U.S. patent application number 11/101834 was filed with the patent office on 2005-09-08 for modular semiconductor workpiece processing tool.
Invention is credited to Berner, Robert W., Coyle, Kevin W., Lund, Worm, Schmidt, Wayne J., Woodruff, Daniel J., Zila, Vladimir.
Application Number | 20050193537 11/101834 |
Document ID | / |
Family ID | 24729520 |
Filed Date | 2005-09-08 |
United States Patent
Application |
20050193537 |
Kind Code |
A1 |
Berner, Robert W. ; et
al. |
September 8, 2005 |
Modular semiconductor workpiece processing tool
Abstract
The present invention provides for a semiconductor workpiece
processing tool and methods for handling semiconductor workpiece
therein. The semiconductor workpiece processing tool preferably
includes an interface section comprising at least one interface
module and a processing section comprising a plurality of
processing modules for processing the semiconductor workpieces. The
semiconductor workpiece processing tool may have a conveyor for
transferring the semiconductor workpieces between the interface
modules and the processing modules.
Inventors: |
Berner, Robert W.;
(Kalispell, MT) ; Woodruff, Daniel J.; (Kalispell,
MT) ; Schmidt, Wayne J.; (Kalispell, MT) ;
Coyle, Kevin W.; (Kalispell, MT) ; Zila,
Vladimir; (Carbough, CA) ; Lund, Worm;
(Bellevue, WA) |
Correspondence
Address: |
PERKINS COIE LLP
P.O. BOX 1247
PATENT-SEA
SEATTLE
WA
98111-1247
US
|
Family ID: |
24729520 |
Appl. No.: |
11/101834 |
Filed: |
April 7, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11101834 |
Apr 7, 2005 |
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10157762 |
May 28, 2002 |
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10157762 |
May 28, 2002 |
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09810192 |
Mar 16, 2001 |
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6440178 |
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09810192 |
Mar 16, 2001 |
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08680068 |
Jul 15, 1996 |
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6203582 |
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Current U.S.
Class: |
29/25 |
Current CPC
Class: |
H01L 21/6719 20130101;
H01L 21/67173 20130101; Y10T 29/40 20150115; Y10S 414/141 20130101;
H01L 21/67196 20130101; H01L 21/67742 20130101; H01L 21/6723
20130101; C25D 7/12 20130101 |
Class at
Publication: |
029/025 |
International
Class: |
B21F 041/00 |
Claims
1-4. (canceled)
5. A head assembly for holding a microelectronic workpiece in
electrochemical processing, comprising: a motor having a rotor
axis; a support coupled to the motor to rotate about the rotor
axis, the support being configured to carry a microelectronic
workpiece facedown in a workpiece processing plane generally normal
to the rotor axis; and a plurality of electrical contacts carried
by the support, the electrical contacts having first sections
outside of a workpiece zone where a workpiece is positioned
relative to the support and second sections projecting from the
first sections into a perimeter area of the workpiece zone, wherein
individual second sections of the electrical contacts have (a) an
inclined portion extending at an inclined angle relative to the
workpiece processing plane and (b) a conductive contact region
configured to press against a surface of the workpiece upon which
electrochemical processing is to occur.
6. The head assembly of claim 5 wherein the first sections of the
electrical contacts project from the support member to a level
beyond the workpiece processing plane and the second sections
project from the first sections toward the workpiece processing
plane.
7. The head assembly of claim 5 wherein the inclined portions of
the second sections of the electrical contacts are sloped toward
the workpiece processing plane.
8. A tool for electrochemical processing of microelectronic
workpieces, comprising: a chamber; a head assembly aligned with the
chamber, the head assembly including a motor having a rotor axis, a
support coupled to the motor to rotate about the rotor axis, and a
plurality of electrical contacts carried by the support, wherein
the support is configured to carry a microelectronic workpiece
facedown in a workpiece processing plane generally normal to the
rotor axis, and the contacts have first sections outside of a
workpiece zone where a workpiece is positioned relative to the
support and second sections projecting from the first sections, and
wherein individual second sections of individual electrical
contacts have (a) an inclined portion extending at an inclined
angle relative to the workpiece processing plane and (b) a
conductive contact region configured to press against a surface of
the workpiece upon which electrochemical processing is to
occur.
9. The tool of claim 8 wherein the first sections of the electrical
contacts project from the support member to a level beyond the
workpiece processing plane and the second sections project from the
first sections toward the workpiece processing plane.
10. The tool of claim 8 wherein the inclined portions of the second
sections are sloped toward the workpiece processing plane.
Description
TECHNICAL FIELD
[0001] The present invention relates to tools for performing liquid
and gaseous processing of semiconductor workpieces, and more
particularly to tools which process semiconductor workpieces
requiring low contaminant levels.
BACKGROUND OF THE INVENTION
[0002] Semiconductor workpieces, such as wafers and the like, are
the subject of extensive processing to produce integrated circuits,
data disks and similar articles. During such processing it is often
necessary to treat a particular workpiece or workpiece surface with
either gaseous or liquid chemicals. Such treatment allows for films
or layers of material to be deposited or grown on a workpiece
surface. One method of accomplishing this is to expose the
particular workpiece to desired processing environments in which
desired chemicals are present to form or grow such films or layers.
Some processing regimes involve moving the workpiece within the
processing environment to effectuate film or layer coverage.
[0003] It has been increasingly desirable to minimize the size of
features in integrated circuits during such processing to provide
circuits having reduced size and increased integration and
capacity. However, the reduction in feature size of such circuits
is limited by contaminants such as particles, crystals, metals and
organics which can cause defects and render the circuit
inoperational. These limitations in feature size caused by
contaminants have prevented utilization of full resolution
capability of known processing techniques.
[0004] It is therefore highly desirable to conduct such
semiconductor workpiece processing within a regulated environment
which preferably involves some type of automated or computer
controlled processing. The regulated environment has minimal human
contact to provide a low contaminant environment. Providing a
regulated environment reduces the chances of an inadvertent
contamination which could render the workpiece useless.
[0005] Therefore, an increased need exists for providing a
processing environment which adequately performs semiconductor
workpiece processing steps in the presence of minimal
contaminants.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Preferred embodiments of the invention are described below
with reference to the accompanying drawings, which are briefly
described below.
[0007] FIG. 1 is an isometric view of the semiconductor workpiece
processing tool in accordance with the present invention.
[0008] FIG. 2 is a cross-sectional view taken along line 2-2 of the
semiconductor workpiece processing tool shown in FIG. 1.
[0009] FIGS. 3-8 are a diagrammatic representation of a workpiece
cassette turnstile and elevator of a preferred interface module of
the semiconductor workpiece processing tool according to the
present invention operating to exchange workpiece cassettes between
a hold position and an extraction position.
[0010] FIG. 9 is an isometric view of a preferred workpiece
cassette tray engageable with the turnstile of an interface module
of the semiconductor workpiece processing tool.
[0011] FIG. 10 is an isometric view of an embodiment of a
semiconductor workpiece conveyor of the semiconductor workpiece
processing tool in accordance with the present invention.
[0012] FIG. 11 is a cross-sectional view taken along line 11-11 of
the semiconductor workpiece conveyor shown in FIG. 10.
[0013] FIG. 12 is a first isometric view of an embodiment of a
semiconductor workpiece transport unit of the semiconductor
workpiece conveyor shown in FIG. 10.
[0014] FIG. 13 is a second isometric view of the semiconductor
workpiece transport unit shown in FIG. 12 with the cover thereof
removed.
[0015] FIG. 14 is a functional block diagram of an embodiment of a
control system of the semiconductor workpiece processing tool in
accordance with the present invention.
[0016] FIG. 15 is a functional block diagram of a master/slave
control configuration of an interface module control subsystem for
controlling a workpiece cassette interface module of the processing
tool.
[0017] FIG. 16 is a functional block diagram of an interface module
control subsystem coupled with components of a workpiece cassette
interface module of the processing tool.
[0018] FIG. 17 is a functional block diagram of a workpiece
conveyor control subsystem coupled with components of a workpiece
conveyor of the processing tool.
[0019] FIG. 18 is a functional block diagram of a workpiece
processing module control subsystem coupled with components of a
workpiece processing module of the processing tool.
[0020] FIG. 19 is a functional block diagram of a stave processor
of the interface module control subsystem shown in FIG. 16 coupled
with components of a workpiece interface module of the processing
tool.
[0021] FIG. 20 is a functional block diagram of a slave processor
of the workpiece conveyor control subsystem shown in FIG. 17
coupled with components of a workpiece conveyor of the processing
tool.
[0022] FIG. 21 is a functional block diagram of a slave processor
of the workpiece processing module control subsystem shown in FIG.
18 coupled with components of a workpiece processing module of the
processing tool.
[0023] FIG. 22 is an environmental view of the semiconductor
processing head of the present invention showing two processing
heads in a processing station, one in a deployed, "closed" or
"processing" position, and one in an "open" or "receive wafer"
position.
[0024] FIG. 23 is an isometric view of the semiconductor processing
head of the present invention.
[0025] FIG. 24 is a side elevation view of the processing head of
the present invention showing the head in a "receive wafer"
position.
[0026] FIG. 25 is a side elevation view of the processing head of
FIG. 5 showing the head in a rotated position ready to lower the
wafer into the process station.
[0027] FIG. 26 is a side elevation view of the processing head of
FIG. 5 showing the head operator pivoted to deploy the processing
head and wafer into the bowl of the process station.
[0028] FIG. 27 is a schematic front elevation view of the
processing head indicating the portions detailed in FIGS. 28 and
29.
[0029] FIG. 28 is a front elevation sectional view of the left half
of the processing head of the apparatus of the present invention
also showing a first embodiment of the wafer holding fingers.
[0030] FIG. 29 is a front elevation sectional view of the left half
of the processing head of the apparatus of the present invention
also showing a first embodiment of the wafer holding fingers.
[0031] FIG. 30 is an isometric view of the operator base and
operator arm of the apparatus of the present invention with the
protective cover removed.
[0032] FIG. 31 is a right side elevation view of the operator arm
of the present invention showing the processing head pivot drive
mechanism.
[0033] FIG. 32 is a left side elevation view of the operator arm of
the present invention showing the operator arm drive mechanism.
[0034] FIG. 33 is schematic plan view of the operator arm
indicating the portions detailed in FIGS. 34 and 35.
[0035] FIG. 34 is a partial sectional plan view of the right side
of the operator arm showing the processing head drive
mechanism.
[0036] FIG. 35 is a partial sectional plan view of the left side of
the operator arm showing the operator arm drive mechanism.
[0037] FIG. 36 is a side elevational view of a semiconductor
workpiece holder constructed according to a preferred aspect of the
invention.
[0038] FIG. 37 is a front sectional view of the FIG. 1
semiconductor workpiece holder.
[0039] FIG. 38 is a top plan view of a rotor which is constructed
in accordance with a preferred aspect of this invention, and which
is taken along line 3-3 in FIG. 37.
[0040] FIG. 39 is an isolated side sectional view of a finger
assembly constructed in accordance with a preferred aspect of the
invention and which is configured for mounting upon the FIG. 38
rotor.
[0041] FIG. 40 is a side elevational view of the finger assembly of
FIG. 39.
[0042] FIG. 41 is a fragmentary cross-sectional enlarged view of a
finger assembly and associated rotor structure.
[0043] FIG. 42 is a view taken along line 7-7 in FIG. 4 and shows a
portion of the preferred finger assembly moving between an engaged
and disengaged position.
[0044] FIG. 43 is a view of a finger tip of the preferred finger
assembly and shows an electrode tip in a retracted or disengaged
position (solid lines) and an engaged position (phantom lines)
against a semiconductor workpiece.
[0045] FIG. 44 is an isometric view of the apparatus of the present
invention showing a five station plating module.
[0046] FIG. 45 is an isometric view of one embodiment of the
apparatus of the system of FIG. 44 showing the internal components
of the five unit plating module.
[0047] FIG. 46 is an isometric view showing the plating tank and
the process bowls of the system of FIG. 44.
[0048] FIG. 47 is an isometric detail of a plating chamber of the
apparatus of the present invention.
[0049] FIG. 48 is front elevation sectional view of the present
invention showing the plating tank, the plating chambers, and the
associated plumbing.
[0050] FIG. 49 is side elevation sectional view of the present
invention showing the plating tank and a plating chamber.
[0051] FIG. 50 is a side sectional view of the apparatus of the
present invention showing a workpiece support positioned over an
electroplating process bowl.
[0052] FIG. 51 is a side sectional view of the apparatus of the
present invention showing a workpiece support supporting a
workpiece for processing within an electroplating process bowl.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] This disclosure of the invention is submitted in furtherance
of the constitutional purposes of the U.S. Patent Laws "to promote
the progress of science and useful arts" (Article 1, Section
8).
1TABLE 1 Listing of Subsections of Detailed Description and
Pertinent Items with Reference Numerals and Page Numbers Processing
Tool Generally 12 semiconductor workpiece processing 12 tool 10
interface section 12 13 processing section 14 13 workpiece
cassettes 16 13 first port 32 13 second port 33 13 powered doors
35, 36 13 plating module 20 14 pre-wet module 22 14 resist strip
module 24 14 rear closure surface 18 15 air supply 26 15 exhaust
ducts 58, 59 15 frame 65 15 workpiece transport unit guide 66 15
workpiece transport units 62, 64 16 user interface 30 17 window 34
17 vents 37 17 two interface modules 38, 39 18 workpiece cassette
turnstile 40, 41 18 workpiece cassette elevator 42, 43 18 workpiece
cassette support 47, 48 18 semiconductor workpiece conveyor 60 19
workpiece holder 810 19 workpiece support 401 20 finger assemblies
409 20 Interface Module 22 saddles 45, 46 23 turnstile shaft 49 24
powered shaft 44 25 Workpiece Cassette Tray 26 workpiece cassette
tray 50 26 base 51 26 upright portion 54 26 lateral supports 52 26
groove 53 26 Semiconductor Workpiece Conveyor 27 paths of movement
68, 70 28 guide rails 63, 64 28 Extensions 69, 75 28 drive
operators 71, 74 28 electromagnet 79 29 Cable guards 72, 73 29
linear bearing 76 29 horizontal roller 77 29 Semiconductor
Workpiece Transport Units 30 train 84 30 workpiece transfer arm
assembly 86 30 workpiece transfer arm elevator 90 30 cover 85 30
first arm extension 87 30 shaft 83 30 second arm extension 88 31
axis 82 31 wafer support 89 31 light or other beam emitter 81 32
CCD array 91 32 Control System Generally 32 control system 100 32
grand master controller 101 33 interface module control 110 33
conveyor control 113 33 processing module controls 114, 115 33
additional grand master controllers 102 33 additional processing
module control 34 119 memory mapped devices 160, 161, 162 34 master
controllers 130, 131, 132 34 Master/Slave Configuration 35 data
link 126, 127, 129 as shown in FIG. 36 16-FIG. 18 slave controllers
140, 141, 142 36 turnstile motor 185 38 incremental turnstile
encoder 190 38 saddle motor 186 38 saddle encoder 191 38 Conveyor
Control Subsystem 39 slave processor 171 40 servo controller 176 40
linear encoder 196 40 transfer arm motor 194 40 transfer arm
rotation encoder 197 40 transfer arm elevation motor 195 41
transfer arm elevation encoder 198 41 Absolute encoders 199 41
Processing Module Control 41 slave controller 145, 146 42 process
components 184 42 servo controller 177 42 interface controller 180
42 slave processor 172 43 servo controller 177 43 operator arm 407
43 lift drive shaft 456 43 lift motion encoder 455 43 lift arm 407
43 rotate motor 428 43 processing head 406 43 shafts 429, 430 43
Incremental rotate encoder 435 43 Spin motor 480 43 workpiece
holder 478 43 spin encoder 498 43 fingertips 414 43 pneumatic valve
actuator 201 43 pneumatic piston 502 43 relay 202 44 pump 605 44
Interface Module Control 45 Slave processor 170 45 servo controller
175 46 elevator lift motor 187 46 elevator rotation motor 188 46
ift encoder 192 47 rotation encoder 193 47 Absolute encoders 199 47
Methods 47 Workpiece Support 49 semiconductor processing machine
400 49 workpiece supports 401 49 Workpiece support 402 49 Workpiece
support 403 50 semiconductor manufacturing chamber 50 404 beam
emitter 81 50 operator base 405 50 processing head 406 50 operator
arm 407 50 wafer holder 408 50 fingers 409 50 Workpiece holder 408
50 workpiece spin axis 410 50 process pivot axis 411 50 operator
pivot axis 412 50 workpiece W 51 fingertips 414 51 51 processing
bowl 417 51 left and rigbt forks 418 and 419 52 Operator Base 52
operator base back portion 420 52 operator base left yoke arm 421
53 operator base right yoke arm 422 53 yoke arm fasteners 423 53
operator arm bearings 424 53 operator arm 425 53 Operator Arm 53
process arm rear cavity 426 54 lift motor 452 54 rotate motor 428
54 processing head left pivot shaft 429 54 processing head right
pivot shaft 430 54 Operator Arm-Processing Head Rotate Mechanism 54
Processing head rotate mechanism 431 54 rotate shaft 432 54
securing collar 433 55 rotate motor support 434 55 rotate encoder
435 55 rotate pulley inboard bearing 436 56 rotate belt 437 56
processing head pulley 438 56 rotate belt tensioner 439 56
tensioner hub 468 57 processing head shaft bearing 440 57
processing head rotate bearing 469 57 processing head shaft bearing
441 57 cable brackets 442 and 443 57 rotate overtravel protect 444
58 rotate flag 447 58 Rotate optical switches 445 and 446 59
Operator Arm-Lift Mechanism 59 operator arm lift mechanism 448 59
lift motor shaft 454 59 lift gear drive 453 60 lift drive shaft 456
60 lift bushing 449 60 anchor plate 458 60 anchor fasteners 457 60
60 Lift bearing 450 60 lift bearing support 460 60 operator arm
frame 461 60 lift anchor 451 61 lift overtravel protect 462 61 lift
optical switch low 463 61 lift optical switch high 464 61 lift flag
465 62 lift motor encoder 455 62 lift motor 452 62 slotted lift
flag mounting slots 467 62 lift flag fasteners 466 62 Processing
Head 62 processing head housing 470 63 circumferential grooves 471
63 rotate shaft openings 474 and 475 63 left and right processing
head mounts 63 472 processing head door 476 63 processing head void
477 63 Processing Head Spin Motor 64 workpiece holder 478 64 spin
axis 479 64 spin motor 480 64 top motor housing 481 65 spin motor
shaft 483 65 workpiece holder rotor 484 65 65 rotor hub 485 65
rotor hub recess 486 65 workpiece shaft snap-ring 488 65 rotor
recess-groove 489 65 spin encoder 498 66 optical tachometer 499 66
Processing Head Finger Actuators 68 Pneumatic piston 502 69
actuator spring 505 69 cavity end cap 507 69 retaining ring 508 69
pneumatic inlet 503 69 pneumatic supply line 504 69 actuator plate
509 69 actuator plate connect screw 510 69 Wave springs 529 69
bushing 512 69 pneumatic piston recess 511 69 finger actuator
contacts 513 70 Processing Head Workpiece Holder 70 finger actuator
lever 514 70 finger stem 515 70 finger diaphragm 519 70 workpiece
holder rotor 484 71 finger opening 521 71 rotor diaphragm lip 523
71 finger spring 520 71 finger actuator tab 522 71 finger collar or
nut 517 71 518 71 finger actuator mechanism 500 71 cavity 501 72
Semiconductor Workpiece Holder -- Electroplating Embodiment 72
semiconductor workpiece holder 810 72 bottom half or bowl 811 73
Processing Head and Processing Head Operator 73 workpiece support
812 73 spin head assembly 814 73 lift/rotate assembly 816 73 motor
818 74 rotor 820 74 rotor spin axis 822 74 finger assembly 824 74
actuator 825 75 rotor center piece 826 75 spokes 828 75 rotor
perimeter piece 830 75 Finger Assembly 76 finger assembly frame 832
77 angled slot 832a 77 finger assembly frame outer flange 834 77
inner drive plate portion 836 77 Finger Assembly Drive System 77
bearing 838 77 collet 840 77 bearing receptacle 839 77 spring 842
78 spring seat 844 78 Finger Assembly Electrical System 78 pin
connector 846 79 finger 848 79 nut 850 79 anti-rotation pin 852 79
finger tip 854 79 electrode contact 858 80 Finger Assembly Drive
System Interface 80 finger actuator 862 80 863 80 first movement
path axis 864 81 secondary linkage 865 81 link arm 867 81 actuator
torque ring 869 81 pneumatic operator 871 81 Engaged and Disengaged
Positions 82 arrow A 82 workpiece standoff 865 83 bend 866 83
Finger Assembly Seal 84 868 84 rim portion 870 84 Methods and
Operation 85 Methods Re Presenting Workpiece 88 Electroplating
Processing Station 91 electroplating module 20 91 workpiece support
401 92 processing head 406 92 operator arm 407 92 operator base 405
92 fingers 409 92 beam emitter 81 93 plating chamber assemblies 603
93 process fluid reservoir 604 93 immersible pump 605 93 module
frame or chassis 606 93 pump discharge filter 607 93 outer
reservoir wall 608 93 inner reservoir wall 609 93 reservoir safety
volume 611 94 inner vessel 612 94 reservoir overflow opening 610 94
heat exchanger 613 94 exchanger inlet 614 94 exchanger outlet 615
94 Bowl Assembly 94 reservoir top 618 95 process bowl or plating
chamber 616 95 bowl side 617 95 bowl bottom 619 95 cup assembly 620
95 fluid cup 621 95 cup side 622 95 cup bottom 623 95 fluid inlet
line 625 95 bowl bottom opening 627 95 cup fluid inlet opening 624
95 inlet line end point 631 95 Fluid outlet openings 628 95 inlet
plenum 629 95 cup filter 630 95 metallic anode 634 96 annular gap
or space 635 96 outer cup wall 636 96 first annular space or
process fluid 96 overflow space 632 cup upper edge 633 96 bowl
upper edge 637 96 crossbars 626 97 bowl bottom center plate 639 97
fluid return openings 638 97 process module deck plate 666 99
levelers 640 99 compliant bowl seal 665 100 cup height adjuster 641
100 cup height adjustment jack 643 100 cup lock nut 642 100 height
adjustment jack 641 100 adjustment tool access holes 667 100 anode
height adjuster 646 101 threaded anode post 664 101 threaded anode
adjustment sleeve 663 101 sleeve openings 668 101 fluid outlet
chamber 662 101 Fluid Transfer Equipment 102 pump suction 647 102
pump body 653 102 pump discharge 648 102 Electric pump motor 650
102 removable filter top 649 103 supply manifold 652 103 fluid
return line 654 103 optional end point 655 103 back pressure
regulator 656 103 Control Devices 104 flow sensors 657 104 flow
signal line 659 104 flow restrictors 658 104 flow control signal
line 660 104 Plating Methods 105
[0054] Processing Tool Generally
[0055] Referring to FIG. 1, a present preferred embodiment of the
semiconductor workpiece processing tool 10 is shown. The processing
tool 10 may comprise an interface section 12 and processing section
14. Semiconductor workpiece cassettes 16 containing a plurality of
semiconductor workpieces, generally designated W, may be loaded
into the processing tool 10 or unloaded therefrom via the interface
section 12. In particular, the workpiece cassettes 16 are
preferably loaded or unloaded through at least one port such as
first port 32 within a front outwardly facing wall of the
processing tool 10. An additional second port 33 may be provided
within the interface section 12 of the processing tool 10 to
improve access and port 32 may be utilized as an input and port 33
may be utilized as an output.
[0056] Respective powered doors 35, 36 may be utilized to cover
access ports 32, 33 thereby isolating the interior of the
processing tool 10 from the clean room. Each door 35, 36 may
comprise two portions. The upper portions and lower portion move
upward and downward, respectively, into the front surface of the
processing tool 10 to open ports 32, 33 and permit access
therein.
[0057] Workpiece cassettes 16 are typically utilized to transport a
plurality of semiconductor workpieces. The workpiece cassettes 16
are preferably oriented to provide the semiconductor workpieces
therein in an upright or vertical position for stability during
transportation of the semiconductor workpieces into or out of the
processing tool 10.
[0058] The front outwardly facing surface of the processing tool 10
may advantageously join a clean room to minimize the number of
harmful contaminants which may be introduced into the processing
tool 10 during insertion and removal of workpiece cassettes 16. In
addition, a plurality of workpiece cassettes 16 may be introduced
into processing tool 10 or removed therefrom at one time to
minimize the opening of ports 32, 33 and exposure of the processing
tool 10 to the clean room environment.
[0059] The interface section 12 joins a processing section 14 of
the processing tool 10. The processing section 14 may include a
plurality of semiconductor workpiece processing modules for
performing various semiconductor process steps. In particular, the
embodiment of the processing tool 10 shown in FIG. 1 includes a
plating module 20 defining a first lateral surface of the
processing section 14. The processing section 14 of the tool 10 may
advantageously include additional modules, such as pre-wet module
22 and resist strip module 24, opposite the plating module 20.
[0060] Alternatively, other modules for performing additional
processing functions may also be provided within the processing
tool 10 in accordance with the present invention. Pre-wet module 22
and resist strip module 24 define a second lateral surface of the
processing tool 10. The specific processing performed by processing
modules of the processing tool 10 may be different or of similar
nature. Various liquid and gaseous processing steps can be used in
various sequences. The processing tool 10 is particularly
advantageous in allowing a series of complex processes to be run
serially in different processing modules set up for different
processing solutions. All the processing can be advantageously
accomplished without human handling and in a highly controlled
working space 11, thus reducing human operator handling time and
the chance of contaminating the semiconductor workpieces.
[0061] The processing modules of the process tool 10 in accordance
with the present invention are preferably modular, interchangeable,
stand-alone units. The processing functions performed by the
processing tool 10 may be changed after installation of the
processing tool 10 increasing flexibility and allowing for changes
in processing methods. Additional workpiece processing modules may
be added to the processing tool 10 or replace existing processing
modules 19.
[0062] The processing tool 10 of the present invention preferably
includes a rear closure surface 18 joined with the lateral sides of
the processing tool 10. As shown in FIG. 1, an air supply 26 may be
advantageously provided intermediate opposing processing modules of
the processing section 14. The interface section 12, lateral sides
of the processing section 14, closure surface 18, and air supply 26
preferably provide an enclosed work space 11 within the processing
tool 10. The air supply 26 may comprise a duct coupled with a
filtered air source (not shown) for providing clean air into the
processing tool 10 of the present invention. More specifically, the
air supply 26 may include a plurality of vents intermediate the
processing modules 19 for introducing clean air into work space
11.
[0063] Referring to FIG. 10, exhaust ducts 58, 59 may be provided
adjacent the frame 65 of a workpiece transport unit guide 66 to
remove the circulated clean air and the contaminants therein.
Exhaust ducts 58, 59 may be coupled with the each of the processing
modules 19 for drawing supplied clean air therethrough. In
particular, clean air is supplied to the workspace 11 of the
processing tool 10 via air supply 26. The air may be drawn adjacent
the workpiece transport units 62, 64 and into the processing
modules 19 via a plurality of vents 57 formed within a shelf or
process deck thereof by an exhaust fan (not shown) coupled with the
output of exhaust ducts 58, 59. Each processing module 19 within
the processing tool 10 may be directly coupled with ducts 58, 59.
The air may be drawn out of the ducts 58, 59 of the processing tool
10 through the rear closant surface 18 or through a bottom of
surface of the processing tool 10. Providing an enclosed work space
and controlling the environment within the work space greatly
reduces the presence of contaminants with the processing tool
10.
[0064] Each of the processing modules 20, 22, 24 may be
advantageously accessed through the rear panel of the respective
module forming the lateral side of the processing tool 10. The
lateral sides of the processing tool 10 may be adjacent a gray room
environment. Gray rooms have fewer precautions against
contamination compared with the clean rooms. Utilizing this
configuration reduces plant costs while allowing access to the
processing components and electronics of each workpiece module 19
of the processing tool 10 which require routine maintenance.
[0065] A user interface 30 may be provided at the outwardly facing
front surface of the processing tool as shown in FIG. 1. The user
interface 30 may advantageously be a touch screen cathode ray tube
control display allowing finger contact to the display screen to
effect various control functions within the processing tool 10. An
additional user interface 30 may also be provided at the rear of
the processing tool 10 or within individual processing modules 20,
22, 24 so that processing tool 10 operation can be effected from
alternate locations about the processing tool 10. Further, a
portable user interface 30 may be provided to permit an operator to
move about the processing tool 10 and view the operation of the
processing components therein. The user interface 30 may be
utilized to teach specified functions and operations to the
processing modules 19 and semiconductor workpiece transport units
62, 64.
[0066] Each module 20, 22, 24 within the processing tool 10
preferably includes a window 34 allowing visual inspection of
processing tool 10 operation from the gray room. Further, vents 37
may be advantageously provided within a top surface of each
processing module 20, 22, 24. Processing module electronics are
preferably located adjacent the vents 37 allowing circulating air
to dissipate heat generated by such electronics.
[0067] The work space 11 within the interface section 12 and
processing section 14 of an embodiment of the processing tool 10 is
shown in detail in FIG. 2.
[0068] The interface section 12 includes two interface modules 38,
39 for manipulating workpiece cassettes 16 within the processing
tool 10. The interface modules 38, 39 receive workpiece cassettes
16 through the access ports 32, 33 and may store the workpiece
cassettes 16 for subsequent processing of the semiconductor
workpieces therein. In addition, the interface modules 38, 39 store
the workpiece cassettes for removal from the processing tool 10
upon completion of the processing a of the semiconductor workpieces
within the respective workpiece cassette 16.
[0069] Each interface module 38, 39 may comprise a workpiece
cassette turnstile 40, 41 and a workpiece cassette elevator 42, 43.
The workpiece cassette turnstiles 40, 41 generally transpose the
workpiece cassettes 16 from a stable vertical orientation to a
horizontal orientation where access to the semiconductor workpieces
is improved. Each workpiece cassette elevator 42, 43 has a
respective workpiece cassette support 47, 48 for holding workpiece
cassettes 16. Each workpiece cassette elevator 42, 43 is utilized
to position a workpiece cassette 16 resting thereon in either a
transfer position and extraction position. The operation of the
workpiece interface modules 38, 39 is described in detail
below.
[0070] In a preferred embodiment of the present invention, the
first workpiece interface module 38 may function as an input
workpiece cassette interface for receiving unprocessed
semiconductor workpieces into the processing tool 10. The second
workpiece interface module 39 may function as an output workpiece
cassette interface for holding processed semiconductor workpieces
for removal from the processing tool 10. Workpiece transport units
62, 64 within the processing tool 10 may access workpiece cassettes
16 held by either workpiece interface module 38, 39. Such an
arrangement facilitates transferring of semiconductor workpieces
throughout the processing tool 10.
[0071] A semiconductor workpiece conveyor 60 is shown intermediate
processing modules 20, 22, 24 and interface modules 38, 39 in FIG.
2. The workpiece conveyor 60 includes workpiece transport units 62,
64 for transferring individual semiconductor workpieces W between
each of the workpiece interface modules 38, 39 and the workpiece
processing modules 19.
[0072] Workpiece conveyor. 60 advantageously includes a transport
unit guide 66, such as an elongated rail, which defines a plurality
of paths 68, 70 for the workpiece transport units 62, 64 within the
processing tool 10. A workpiece transport unit 62 on a first path
68 may pass a workpiece transport unit 64 positioned on a second
path 70 during movement of the transport units 62, 64 along
transport guide 66. The processing tool 10 may include additional
workpiece transport units to facilitate the transfer of
semiconductor workpieces W between the workpiece processing modules
20, 22, 24 and workpiece interface modules 38, 39.
[0073] Each processing module 20, 22, 24 includes at least one
semiconductor workpiece holder such as workpiece holder 810 located
generally adjacent the workpiece conveyor 60. In particular, each
of the workpiece transport units 62, 64 may deposit a semiconductor
workpiece upon a semiconductor workpiece support 401 of the
appropriate semiconductor processing module 20, 22, 24.
Specifically, workpiece transport unit 64 is shown accessing an
semiconductor workpiece support 401 of processing module 20. The
workpiece transport units may either deposit or retrieve workpieces
on or from the workpiece supports 401.
[0074] More specifically, the second arm extension 88 may support a
semiconductor workpiece W via vacuum support 89. The appropriate
workpiece transport unit 62, 64 may approach a workpiece support
401 by moving along transport unit guide 66. After reaching a
proper location along guide 66, the first extension 87 and second
extension 88 may rotate to approach the workpiece support 401. The
second extension 88 is positioned above the workpiece support 401
and subsequently lowered toward engagement finger assemblies 409 on
the workpiece support 401. The vacuum is removed from vacuum
support 89 and finger assemblies 409 grasp the semiconductor
workpiece W positioned therein. Second extension 88 may be lowered
and removed from beneath the semiconductor workpiece held by the
workpiece engagement fingers.
[0075] Following completion of processing of the semiconductor
workpiece within the appropriate processing module 20, 22, 24, a
workpiece transport unit 62, 64 may retrieve the workpiece and
either deliver the workpiece to another processing module 20, 22,
24 or return the workpiece to a workpiece cassette 16 for storage
or removal from the processing tool 10.
[0076] Each of the workpiece transport units 62, 64 may access a
workpiece cassette 16 adjacent the conveyor 60 for retrieving a
semiconductor workpiece from the workpiece cassette 16 or
depositing a semiconductor workpiece therein. In particular,
workpiece transport unit 62 is shown withdrawing a semiconductor
workpiece W from workpiece cassette 16 upon elevator 42 in FIG.
2.
[0077] More specifically, the second extension 88 and vacuum
support 89 connected therewith may be inserted into a workpiece
cassette 16 positioned in the extraction position. Second extension
88 and vacuum support 89 enter below the lower surface of the
bottom semiconductor workpiece W held by workpiece cassette 16. A
vacuum may be applied via vacuum support 89 once support 89 is
positioned below the center of the semiconductor workpiece W being
removed. The second extension 88, vacuum support 89 and
semiconductor workpiece W attached thereto may be slightly raised
via transfer arm elevator 90. Finally, first extension 87 and
second extension 88 may be rotated to remove the semiconductor
workpiece W from the workpiece cassette 16. The workpiece transport
unit 62, 64 may thereafter deliver the semiconductor workpiece W to
a workpiece processing module 19 for processing.
[0078] Thereafter, workpiece transport unit 62 may travel along
path 68 to a position adjacent an appropriate processing module 20,
22, 24 for depositing the semiconductor workpiece upon workpiece
processing support 401 for processing of the semiconductor
workpiece.
[0079] Interface Module
[0080] Referring to FIG. 3-FIG. 8, the operation of the interface
module 38 is shown in detail. The following discussion is limited
to workpiece interface module 38 but is also applicable to
workpiece interface module 39 inasmuch as each interface module 38,
39 may operate in substantially the same manner.
[0081] Preferably, the first workpiece interface module 38 and the
second workpiece interface module 39 may function as a respective
semiconductor workpiece cassette 16 input module and output module
of the processing tool 10. Alternately, both modules can function
as both input and output. More specifically, workpiece cassettes 16
holding unprocessed semiconductors workpieces may be brought into
the processing tool 10 via port 32 and temporarily stored within
the first workpiece interface module 38 until the semiconductor
workpieces are to be removed from the workpiece cassette 16 for
processing. Processed semiconductor workpieces may be delivered to
a workpiece cassette 16 within the second workpiece interface
module 39 via workpiece transport units 62, 64 for temporary
storage and/or removal from the processing tool 10.
[0082] The workpiece interface modules 38, 39 may be directly
accessed by each of the workpiece transport units 62, 64 within the
processing tool 10 for transferring semiconductor workpieces
therebetween. Providing a plurality of workpiece cassette interface
modules 38, 39 accessible by each workpiece transport unit 62, 64
facilitates the transport of semiconductor workpieces W throughout
the processing tool 10 according to the present invention.
[0083] Each workpiece interface module 38, 39 preferably includes a
workpiece cassette turnstile 40 and a workpiece cassette elevator
42 adjacent thereto. The access ports 32, 33 are adjacent the
respective workpiece cassette turnstiles 40, 41. Workpiece
cassettes 16 may be brought into the processing tool 10 or removed
therefrom via ports 32, 33.
[0084] Workpiece cassettes 16 are preferably placed in a vertical
position onto cassette Frays 50 prior to delivery into the
processing tool 10. Cassette trays 50 are shown in detail in FIG.
9. The vertical position of workpiece cassettes 16 and the
semiconductor workpieces therein provides a secure orientation to
maintain the semiconductor workpieces within the workpiece cassette
16 for transportation.
[0085] Each workpiece cassette turnstile 40, 41 preferably includes
two saddles 45, 46 each configured to hold a workpiece cassette 16.
Providing two saddles 45, 46 enables two workpiece cassettes 16 to
be placed into the processing tool 10 or removed therefrom during a
single opening of a respective access door 35, 36 thereby
minimizing exposure of the workspace 11 within the processing tool
10 to the clean room environment.
[0086] Each saddle 45, 46 includes two forks engageable with the
cassette tray 50. Saddles 45, 46 are powered by motors within the
workpiece cassette turnstile shaft 49 to position the workpiece
cassette 16 in a horizontal or vertical orientation. The workpiece
cassettes 16 and semiconductor workpieces therein are preferably
vertically oriented for passage through the access ports 32, 33 and
horizontally oriented in a transfer or extraction position to
provide access of the workpieces therein to the workpiece transport
units 62, 64.
[0087] The workpiece cassette 16 held by workpiece cassette
turnstile 40 in FIG. 3, also referred to as workpiece cassette 15,
is in a hold position (also referred to herein as a load position).
The semiconductor workpieces within a workpiece cassette 16 in the
hold position may be stored for subsequent processing.
Alternatively, the semiconductor workpieces within a workpiece
cassette 16 in the hold position may be stored for subsequent
removal from the processing tool 10 through an access port 32,
33.
[0088] Referring to FIG. 3, the workpiece cassette 16 supported by
the workpiece cassette elevator 42, also referred to as workpiece
cassette 17, is in an extraction or exchange position.
Semiconductor workpieces may either be removed from or placed into
a workpiece cassette 16 positioned in the extraction position via a
workpiece transport unit 62, 64.
[0089] The workpiece cassette turnstile 41 and workpiece cassette
elevator 42 may exchange workpiece cassettes 15, 17 to transfer a
workpiece cassette 17 having processed semiconductor workpieces
therein from the extraction position to the hold position for
removal from the processing tool 10. Additionally, such an exchange
may transfer a workpiece cassette 15 having unprocessed
semiconductor workpieces therein from the hold position to the
extraction position providing workpiece transport units 62, 64 with
access to the semiconductor workpiece therein.
[0090] The exchange of workpiece cassettes 15, 17 is described with
reference to FIG. 4-FIG. 8. Specifically, saddle 46 is positioned
below a powered shaft 44 of workpiece cassette elevator 42. Shaft
44 is coupled with a powered workpiece cassette support 47 for
holding a workpiece cassette 16. Shaft 44 and workpiece cassette
support 47 attached thereto are lowered as shown in FIG. 4 and
shaft 44 passes between the forks of saddle 46.
[0091] Referring to FIG. 5, a motor within shaft 44 rotates
workpiece cassette support 47 about an axis through shaft 44
providing the workpiece cassette 17 thereon in an opposing relation
to the workpiece cassette 15 held by workpiece cassette turnstile
40. Both saddles 45, 46 of workpiece cassette turnstile 40 are
subsequently tilted into a horizontal orientation as shown in FIG.
6. The shaft 44 of workpiece cassette elevator 42 is next lowered
and workpiece cassette 17 is brought into engagement with saddle 46
as depicted in FIG. 7. The shaft 44 and workpiece cassette support
47 are lowered an additional amount to clear rotation of workpiece
cassettes 16. Referring to FIG. 8, workpiece cassette turnstile 40
rotates 180 degrees to transpose workpiece cassettes 15, 17.
[0092] Workpiece cassette 17 having processed semiconductor
workpieces therein is now accessible via port 32 for removal from
the processing tool 10. Workpiece cassette 15 having unprocessed
semiconductors therein is now positioned for engagement with
workpiece cassette support 47. The transfer process steps shown in
FIG. 3-FIG. 8 may be reversed to elevate the workpiece cassette 15
into the extraction position providing access of the semiconductor
workpieces to workpiece transport units 62, 64.
[0093] Workpiece Cassette Tray
[0094] A workpiece cassette tray 50 for holding a workpiece
cassette 16 is shown in detail in FIG. 9. Each cassette tray 50 may
include a base 51 and an upright portion 54 preferably
perpendicular to the base 51. Two lateral supports 52 may be formed
on opposing sides of the base 51 and extend upward therefrom.
Lateral supports 52 assist with maintaining workpiece cassettes 16
thereon in a fixed position during the movement, rotation and
exchange of workpiece cassettes 16. Each lateral support 52
contains a groove 53 preferably extending the length thereof
configured to engage with the forks of saddles 45, 46.
[0095] The workpiece cassette trays 50 are preferably utilized
during the handling of workpiece cassettes 16 within the workpiece
cassette interface modules 38, 39 where the workpiece cassettes 16
are transferred from a load position to an extraction position
providing access of the semiconductor workpieces W to workpiece
transport units 62, 64 within the conveyor 60.
[0096] Semiconductor Workpiece Conveyor
[0097] The processing tool 10 in accordance with the present
invention advantageously provides a semiconductor workpiece
conveyor 60 for transporting semiconductor workpieces throughout
the processing tool 10. Preferably, semiconductor workpiece
conveyor 60 may access each workpiece cassette interface module 38,
39 and each workpiece processing module 19 within processing tool
10 for transferring semiconductor workpieces therebetween. This
includes processing modules from either side.
[0098] One embodiment of the workpiece conveyor 60 is depicted in
FIG. 10. The workpiece conveyor 60 generally includes a workpiece
transport unit guide 66 which preferably comprises an elongated
spine or rail mounted to frame 65. Alternatively, transport unit
guide 66 may be formed as a track or any other configuration for
guiding the workpiece transport units 62, 64 thereon. The length of
workpiece conveyor 60 may be varied and is configured to permit
access of the workpiece transport units 62, 64 to each interface
module 38, 39 and processing modules 20, 22, 24.
[0099] Workpiece transport unit guide 66 defines the paths of
movement 68, 70 of workpiece transport units 62, 64 coupled
therewith. Referring to FIG. 11, a spine of transport unit guide 66
includes guide rails 63, 64 mounted on opposite sides thereof. Each
semiconductor workpiece transport unit 62, 64 preferably engages a
respective guide rail 63, 64. Each guide rail can mount one or more
transport units 62, 64. Extensions 69, 75 may be fixed to opposing
sides of guide 66 for providing stability of the transport units
62, 64 thereagainst and to protect guide 66 from wear. Each
workpiece transport unit 62, 64 includes a roller 77 configured to
ride along a respective extension 69, 75 of guide 66.
[0100] It is to be understood that workpiece conveyor 60 may be
formed in alternate configurations dependent upon the arrangement
of interface modules 38, 39 and processing modules 20, 22, 24
within the processing tool 10. Ducts 58, 59 are preferably in fluid
communication with extensions from each workpiece processing module
19 and an exhaust fan for removing circulated air from the
workspace 11 of the processing tool 10.
[0101] Each workpiece transport unit 62, 64 is powered along the
respective path 68, 70 by a suitable driver. More specifically,
drive operators 71, 74 are advantageously mounted to respective
sides of transport unit guide 66 to provide controllable axial
movement of workpiece transport units 62, 64 along the transport
unit guide 66.
[0102] The drive operators 71, 74 may be linear magnetic motors for
providing precise positioning of workpiece transport units 62, 64
along guide 66. In particular, drive operators 71, 74 are
preferably linear brushless direct current motors. Such preferred
driver operators 71, 74 utilize a series of angled magnetic
segments which magnetically interact with a respective
electromagnet 79 mounted on the workpiece transport units 62, 64 to
propel the units along the transport unit guide 66.
[0103] Cable guards 72, 73 may be connected to respective workpiece
transport units 62, 64 and frame 65 for protecting communication
and power cables therein. Cable guards 72, 73 may comprise a
plurality of interconnected segments to permit a full range of
motion of workpiece transport units 62, 64 along transport unit
guide 66.
[0104] As shown in FIG. 11, a first workpiece transport unit 62 is
coupled with a first side of the spine of guide 66. Each workpiece
transport unit 62, 64 includes a linear bearing 76 for engagement
with linear guide rails 63, 64. Further, the workpiece transport
units 62, 64 each preferably include a horizontal roller 77 for
engaging a extension 69 formed upon the spine of the guide 66 and
providing stability.
[0105] FIG. 11 additionally shows an electromagnet 79 of the first
workpiece transport unit 62 mounted in a position to magnetically
interact with drive actuator 71. Drive actuator 71 and
electromagnet 79 provide axial movement and directional control of
the workpiece transport units 62, 64 along the transport unit guide
66.
[0106] Semiconductor Workpiece Transport Units
[0107] Preferred embodiments of the semiconductor workpiece
transport units 62, 64 of the workpiece conveyor 60 are described
with reference to FIG. 12 and FIG. 13.
[0108] In general, each workpiece transport unit 62, 64 includes a
movable carriage or tram 84 coupled to a respective side of the
transport unit guide 66, a workpiece transfer arm assembly 86
movably connected to the tram 84 for supporting a semiconductor
workpiece W, and a workpiece transfer arm elevator 90 for adjusting
the elevation of the transfer arm assembly 86 relative to tram
84.
[0109] Referring to FIG. 12, a cover 85 surrounds the portion of
tram 84 facing away from the transport unit guide 66. Tram 84
includes linear bearings 76 for engagement With respective guide
rails 63, 64 mounted to transport unit guide 66. Linear bearings 76
maintain the tram 84 in a fixed relation with the transport unit
guide 66 and permit axial movement of the tram 84 therealong. A
roller 77 engages a respective extension 69 for preventing rotation
of tram 84 about guide rail 63, 64 and providing stability of
workpiece transport unit 62. The electromagnet 79 is also shown
connected with the tram 84 in such a position to magnetically
interact with a respective transport unit 62, 64 drive actuator 71,
74.
[0110] A workpiece transfer arm assembly 86 extends above the top
of tram 84. The workpiece transfer arm assembly 86 may include a
first arm extension 87 coupled at a first end thereof with a shaft
83. A second arm extension 88 may be advantageously coupled with a
second end of the first extension 87. The first arm extension 87
may rotate 360 degrees about shaft 83 and second arm extension 88
may rotate 360 degrees about axis 82 passing through a shaft
connecting first and second arm extensions 87, 88.
[0111] Second extension 88 preferably includes a wafer support 89
at a distal end thereof for supporting a semiconductor workpiece W
during the transporting thereof along workpiece conveyor 60. The
transfer arm assembly 86 preferably includes a chamber coupled with
the workpiece support 89 for applying a vacuum thereto and holding
a semiconductor workpiece W thereon.
[0112] Providing adjustable elevation of transfer arm assembly 86,
rotation of first arm extension 87 about the axis of shaft 83, and
rotation of second extension 88 about axis 82 allows the transfer
arm 86 to access each semiconductor workpiece holder 810 of all
processing modules 19 and each of the wafer cassettes 16 held by
interface modules 38, 39 within the processing tool 10. Such access
permits the semiconductor workpiece transport units 62, 64 to
transfer semiconductor workpieces therebetween.
[0113] The cover 85 has been removed from the workpiece transport
unit 62, 64 shown in FIG. 13 to reveal a workpiece transfer arm
elevator 90 coupled with tram 84 and transfer arm assembly 86.
Transfer arm elevator 90 adjusts the vertical position of the
transfer arm assembly 86 relative to the tram 84 during the steps
of transferring a semiconductor workpiece between the workpiece
support 89 and one of a workpiece holder 810 and the workpiece
cassette 16.
[0114] The path position of the tram 84 of each workpiece transport
unit 62, 64 along the transport unit guide 66 is precisely
controlled using a positional indicating array, such as a CCD array
91 of FIG. 13. In one embodiment of the processing tool 10, each
semiconductor workpiece holder 810 within a processing module 19
has a corresponding light or other beam emitter 81 mounted on a
surface of the processing module 19 as shown in FIG. 2 for
directing a beam of light toward the transport unit guide 66. The
light emitter 81 may present a continuous beam or alternatively may
be configured to generate the beam as a workpiece transport unit
62, 64 approaches the respective workpiece holder 810.
[0115] The transfer arm assembly 86 includes an CCD array 91
positioned to receive the laser beam generated by light emitter 81.
A position indicating array 91 on shaft 83 detects the presence of
the light beam to determine the location of tram 84 along transport
unit guide 66. The positional accuracy of the workpiece transport
unit position indicator is preferably in the range less than 0.003
inch (approximately less than 0.1 millimeter).
[0116] Control System Generally
[0117] Referring to FIG. 14, a presently preferred embodiment of
the control system 100 of the semiconductor workpiece processing
tool 10 in accordance with the present invention generally includes
at least one grand master controller 101 for controlling and/or
monitoring the overall function of the processing tool 10.
[0118] The control system 100 is preferably arranged in a
hierarchial configuration. The grand master controller 101 includes
a processor electrically coupled with a plurality of subsystem
control units as shown in FIG. 14. The control subsystems
preferably control and monitor the operation of components of the
corresponding apparatus (i.e., workpiece conveyor 60, processing
modules 20, 22, 24, interface modules 38, 39, etc.). The control
subsystems are preferably configured to receive instructional
commands or operation instructions such as software code from a
respective grand master control 101, 102. The control subsystems
110, 113-119 preferably provide process and status information to
respective grand master controllers 101, 102.
[0119] More specifically, the grand master control 101 is coupled
with an interface module control 110 which may control each of the
semiconductor workpiece interface modules 38, 39. Further, grand
master control 101 is coupled with a conveyor control 113 for
controlling operations of the workpiece conveyor 60 and a plurality
of processing module controls 114, 115 corresponding to
semiconductor workpiece processing modules 20, 22 within the
processing tool 10.
[0120] The control system 100 of the processing tool 10 according
to the present invention may include additional grand master
controllers 102 as shown in FIG. 14 for monitoring or operating
additional subsystems, such as additional workpiece processing
modules via additional processing module control 119. Four control
subsystems may be preferably coupled with each grand master
controller 101, 102. The grand master controllers 101, 102 are
preferably coupled together and each may transfer process data to
the other.
[0121] Each grand master controller 101, 102 receives and transmits
data to the respective modular control subsystems 110-119. In a
preferred embodiment of the control system 100, a bidirectional
memory mapped device is provided intermediate the grand master
controller and each modular subsystem connected thereto. In
particular, memory mapped devices 160, 161, 162 are provided
intermediate the grand master controller 101 and master controllers
130, 131, 132 within respective interface module control 110,
workpiece conveyor control 113 and processing module control
114.
[0122] Each memory mapped device 150, 160-162 within the control
system 100 is preferably a dual port RAM provided by Cypress for
asynchronouosly storing data. In particular, grand master
controller 101 may write data to a memory location corresponding to
master controller 130 and master controller 130 may simultaneously
read the data. Alternatively, grand master controller 101 may read
data from mapped memory device being written by the master
controller 130. Utilizing memory mapped devices 160-161 provides
data transfer at processor speeds. Memory mapped device 150 is
preferably provided intermediate interface 30 and the grand master
controllers 101, 102 for transferring data therebetween.
[0123] A user interface 30 is preferably coupled with each of the
grand master controllers 101, 102. The user interface 30 may be
advantageously mounted on the exterior of the processing tool 10 or
at a remote location to provide an operator with processing and
status information of the processing tool 10. Additionally, an
operator may input control sequences and processing directives for
the processing tool 10 via user interface 30. The user interface 30
is preferably supported by a general purpose computer within the
processing tool 10. The general purpose computer preferably
includes a 486 100 MHz processor, but other processors may be
utilized.
[0124] Master/Slave Configuration
[0125] Each modular control subsystem, including interface module
control 110, workpiece conveyor control 113 and each processing
module control 114-119, is preferably configured in a master/slave
arrangement. The modular control subsystems 110, 113-119 are
preferably housed within the respective module such as workpiece
interface module 38, 39, workpiece conveyor 60, or each of the
processing modules 20, 22, 24. The grand master controller 101 and
corresponding master controllers 130, 131, 132 coupled therewith
are preferably embodied on a printed circuit board or ISA board
mounted within the general purpose computer supporting user
interface 30. Each grand master controller 101, 102 preferably
includes a 68EC000 processor provided by Motorola and each master
controller 130 and slave controller within control system 100
preferably includes a 80251 processor provided by Intel.
[0126] Each master controller 130, 131, 132 is coupled with its
respective slave controllers via a data link 126, 127, 129 as shown
in FIG. 16-FIG. 18. Each data link 126, 127, 129 preferably
comprises a optical data medium such as Optilink provided by
Hewlett Packard. However, data links 126, 127, 129 may comprise
alternate data transfer media.
[0127] Referring to FIG. 15, the master/slave control subsystem for
the interface module control 110 is illustrated. Each master and
related slave configuration preferably corresponds to a single
module (i.e., interface, conveyor, processing) within the
processing tool 10. However, one master may control or monitor a
plurality of modules. The master/slave configuration depicted in
FIG. 15 and corresponding to the interface module control 110 may
additionally apply to the other modular control subsystems 113,
114, 115.
[0128] The grand master controller 101 is connected via memory
mapped device 160 to a master controller 130 within the
corresponding interface module control 110. The master controller
130 is coupled with a plurality of slave controllers 140, 141, 142.
Sixteen slave controllers may be preferably coupled with a single
master controller 130-132 and each slave controller may be
configured to control and monitor a single motor or process
component, or a plurality of motors and process components.
[0129] The control system 100 of the processing tool 10 preferably
utilizes flash memory. More specifically, the operation
instructions or program code for operating each master controller
130-132 and slave controller 140-147 within the control system 100
may be advantageously stored within the memory of the corresponding
grand master controller 101, 102. Upon powering up, the grand
master controller 101, 102 may poll the corresponding master
controllers 130-132 and download the appropriate operation
instruction program to operate each master controller 130-132.
Similarly, each master controller 130-132 may poll respective slave
controllers 140-147 for identification. Thereafter, the master
controller 130-132 may initiate downloading of the appropriate
program from the grand master controller 101, 102 to the respective
slave controller 140-147 via the master controller 130-132.
[0130] Each slave controller may be configured to control and
monitor a single motor or a plurality of motors within a
corresponding processing module 19, interface module 38, 39 and
workpiece conveyor 60. In addition, each slave controller 140-147
may be configured to monitor and control process components 184
within a respective module 19. Any one slave controller, such as
slave controller 145 shown in FIG. 21, may be configured to control
and/or monitor servo motors and process components 184.
[0131] Each slave controller includes a slave processor which is
coupled with a plurality of port interfaces. Each port interface
may be utilized for control and/or monitoring of servo motors and
process components 184. For example, a port may be coupled with a
servo controller card 176 which is configured to operate a
workpiece transfer unit 62, 64. The slave processor 171 may operate
the workpiece transfer unit 62, 64 via the port and servo
controller 176. More specifically, the slave processor 171 may
operate servo motors within the workpiece transfer unit 62, 64 and
monitor the state of the motor through the servo controller
176.
[0132] Alternatively, different slave controllers 140, 141 may
operate different components within a single processing tool
device, such as interface module 38. More specifically, the
interface module control 110 and components of the interface module
38 are depicted in FIG. 16. Slave controller 140 may operate
turnstile motor 185 and monitor the position of the turnstile 40
via incremental turnstile encoder 190. Slave controller 140 is
preferably coupled with the turnstile motor 185 and turnstile
encoder 190 via a servo control card (shown in FIG. 19). Slave
controller 141 may operate and monitor saddle 45 of the turnstile
40 by controlling saddle motor 186 and monitoring saddle encoder
191 via a servo control card.
[0133] A port of a slave processor may be coupled with an interface
controller card 180 for controlling and monitoring process
components within a respective processing module 19. For example, a
flow sensor 657 may provide flow information of the delivery of
processing fluid to a processing bowl within the module. The
interface controller 180 is configured to translate the data
provided by the flow sensors 657 or other process components into a
form which may be analyzed by the corresponding slave processor
172. Further, the interface controller 180 may operate a process
component, such as a flow controller 658, responsive to commands
from the corresponding slave processor 172.
[0134] One slave controller 140-147 may contain one or more servo
controller and one or more interface controller coupled with
respective ports of the slave processor 170-172 for permitting
control and monitor capabilities of various component motors and
processing components from a single slave controller.
[0135] Alternatively, a servo controller and interface controller
may each contain an onboard processor for improving the speed of
processing and operation. Data provided by an encoder or process
component to the servo controller or interface controller may be
immediately processed by the on board processor which may also
control a respective servo motor or processing component responsive
to the data. In such a configuration, the slave processor may
transfer the data from the interface processor or servo controller
processor to the respective master controller and grand master
controller.
[0136] Conveyor Control Subsystem
[0137] The conveyor control subsystem 113 for controlling and
monitoring the operation of the workpiece conveyor 60 and the
workpiece transport units 62, 64 therein is shown in FIG. 17. In
general, a slave controller 143 of conveyor control 113 is coupled
with drive actuator 71 for controllably moving and monitoring a
workpiece transport unit 62 along the guide 66. Further, slave
controller 143 may operate transfer arm assembly 86 of the
workpiece transport unit 62 and the transferring of semiconductor
workpieces thereby. Similarly, slave controller 144 may be
configured to operate workpiece transport unit 64 and drive
actuator 74.
[0138] The interfacing of slave controller 143 and light detector
91, drive actuator 71, linear encoder 196 and workpiece transport
unit 62 is shown in detail in FIG. 20. The slave processor 171 of
slave controller 143 is preferably coupled with a servo controller
176. Slave processor 171 may control the linear position of
workpiece transport unit 62 by operating drive actuator 71 via
servo controller 176. Light detector 91 may provide linear position
information of the workpiece transport unit 62 along guide 66.
Additionally, a linear encoder 196 may also be utilized for
precisely monitoring the position of workpiece transport unit 62
along guide 66.
[0139] The conveyor slave processor 171 may also control and
monitor the operation of the transfer arm assembly 86 of the
corresponding workpiece transport unit 62. Specifically, the
conveyor processor 171 may be coupled with a transfer arm motor 194
within shaft 83 for controllably rotating the first and second arm
extensions 87, 88. An incremental transfer arm rotation encoder 197
may be provided within the shaft 83 of each workpiece transport
unit 62 for monitoring the rotation of transfer arm assembly 86 and
providing rotation data thereof to servo controller 176 and slave
processor 171.
[0140] Slave controller 143 may be advantageously coupled with
transfer arm elevation motor 195 within elevator 90 for controlling
the elevational position of the transfer arm assembly 86. An
incremental transfer arm elevation encoder 198 may be provided
within the transfer arm elevator assembly 90 for monitoring the
elevation of the transfer arm assembly 86.
[0141] In addition, conveyor slave controller 143 may be coupled
with an air supply control valve actuator (not shown) via an
interface controller for controlling a vacuum within wafer support
89 for selectively supporting a semiconductor workpiece
thereon.
[0142] Absolute encoders 199 may be provided within the workpiece
conveyor 60, interface modules 38, 39 and processing modules 19 to
detect extreme conditions of operation and protect servo motors
therein. For example, absolute encoder 199 may detect a condition
where the transfer arm assembly 86 has reached a maximum height and
absolute encoder 199 may turn off elevator 90 to protect transfer
arm elevator motor 195.
[0143] Processing Module Control
[0144] The control system 100 preferably includes a processing
module control subsystem 114-116 corresponding to each workpiece
processing module 20, 22, 24 within the processing tool 10
according to the present invention. The control system 100 may also
include additional processing module control subsystem 119 for
controlling and/or monitoring additional workpiece processing
modules 19.
[0145] Respective processing module controls 114, 115, 116 may
control and monitor the transferring of semiconductor workpieces W
between a corresponding workpiece holder 810 and workpiece
transport unit 62, 64. Further, processing module controls 114,
115, 116 may advantageously control and/or monitor the processing
of the semiconductor workpieces W within each processing module 20,
22, 24.
[0146] Referring to FIG. 18, a single slave controller 147 may
operate a plurality of workpiece holders 401c-401e within a
processing module 20. Alternatively, a single slave controller 145,
146 may operate and monitor a single respective workpiece holder
401a, 401b. An additional slave controller 148 may be utilized to
operate and monitor all process components 184 (i.e., flow sensors,
valve actuators, heaters, temperature sensors) within a single
processing module 19. Further, as shown in FIG. 21, a single slave
controller 145 may operate and monitor a workpiece holder 410 and
process components 184.
[0147] In addition, a single slave controller 145-148 may be
configured to operate and monitor one or more workpiece holder 401
and processing components 184. The interfacing of a slave
controller 145 to both a workpiece holder 401 and process
components is shown in the control system embodiment in FIG. 21. In
particular, a servo controller 177 and interface controller 180 may
be coupled with respective ports connected to slave processor 172
of slave controller 145.
[0148] Slave processor 172 may operate and monitor a plurality of
workpiece holder components via servo controller 177. In
particular, slave processor 172 may operate lift motor 427 for
raising operator arm 407 about lift drive shaft 456. An incremental
lift motion encoder 455 may be provided within a workpiece holder
401 to provide rotational information of lift arm 407 to the
respective slave processor 172 or a processor within servo
controller 177. Slave processor 172 may also control a rotate motor
428 within workpiece holder 401 for rotating a processing head 406
about shafts 429, 430 between a process position and a
semiconductor workpiece transfer position. Incremental rotate
encoder 435 may provide rotational information regarding the
processing head 406 to the corresponding slave processor 172.
[0149] Spin motor 480 may also be controlled by a processor within
servo controller 177 or slave processor 172 for rotating the
workpiece holder 478 during processing of a semiconductor workpiece
W held thereby. An incremental spin encoder 498 is preferably
provided to monitor the rate of revolutions of the workpiece holder
478 and supply the rate information to the slave processor 172.
[0150] Plating module control 114 advantageously operates the
fingertips 414 of the workpiece holder 478 for grasping or
releasing a semiconductor workpiece. In particular, slave processor
172 may operate a valve via pneumatic valve actuator 201 for
supplying air to pneumatic piston 502 for actuating fingertips 414
for grasping a semiconductor workpiece. The slave controller 145
within the plating module control 114 may thereafter operate the
valve actuator 201 to remove the air supply thereby disengaging the
fingertips 414 from the semiconductor workpiece. Slave processor
172 may also control the application of electrical current through
the finger assembly 824 during the processing of a semiconductor
workpiece by operating relay 202.
[0151] The processing module controls 114, 115, 116 preferably
operate and monitor the processing of semiconductor workpieces
within the corresponding workpiece processing modules 20, 22, 24
via instrumentation or process components 184.
[0152] Referring to FIG. 21, the control operation for the plating
processing module 20 is described. Generally, slave processor 172
monitors and/or controls process components 184 via interface
controller 180. Slave processor 172 within the plating module
control 114 operates pump 605 to draw processing solution from the
process fluid reservoir 604 to the pump discharge filter 607. The
processing fluid passes through the filter, into supply manifold
652 and is delivered via bowl supply lines to a plurality of
processing plating bowls wherein the semiconductor workpieces are
processed. Each bowl supply line preferably includes a flow sensor
657 coupled with the plating processing module control 114 for
providing flow information of the processing fluid thereto.
Responsive to the flow information, the slave processor 172 may
operate an actuator of flow controller 658 within each bowl supply
line to control the flow of processing fluid therethrough. Slave
processor 172 may also monitor and control a back pressure
regulator 656 for maintaining a predetermined pressure level within
the supply manifold 652. The pressure regulator 656 may provide
pressure information to the slave processor 172 within the plating
processing control module 114.
[0153] Similarly, processing module control subsystems 115, 116 may
be configured to control the processing of semiconductor workpieces
within the corresponding prewet module 22 and resist module 24.
[0154] Interface Module Control
[0155] Each interface module control subsystem 110 preferably
controls and monitors the operation of workpiece interface modules
38, 39. More specifically, interface module control 110 controls
and monitors the operation of the workpiece cassette turnstiles 40,
41 and elevators 42, 43 of respective semiconductor workpiece
interface modules 38, 39 to exchange workpiece cassettes 16.
[0156] Slave processor 170 within slave controller 140 of interface
module control 110 may operate and monitor the function of the
interface modules 38, 39. In particular, slave processor 170 may
operate doors 35, 36 for providing access into the processing tool
10 via ports 32, 33. Alternatively, master control 100 may operate
doors 35, 36.
[0157] Referring to FIG. 19, an embodiment of the interface module
control portion for controlling workpiece interface module 38 is
discussed. In particular, the slave processor 170 is coupled with
servo controller 175. Either slave processor 170 or a processor on
board servo controller 175 may operate the components of interface
module 38. In particular, slave processor 170 may control turnstile
motor 185 for operating rotate functions of turnstile 40 moving
workpiece cassettes 16 between a load position and a transfer
position. Incremental turnstile encoder 190 monitors the position
of turnstile 40 and provides position data to slave processor 170.
Alternatively, servo controller 175 may include a processor for
reading information from turnstile encoder 190 and controlling
turnstile motor 185 in response thereto. Servo controller 175 may
alert slave processor 170 once turnstile 40 has reaches a desired
position.
[0158] Each workpiece cassette turnstile 40 includes a motor for
controlling the positioning of saddles 45, 46 connected thereto.
The slave processor 170 may control the position of saddles 45, 46
through operation of the appropriate saddle motor 186 to orient
workpiece cassettes 16 attached thereto in one of a vertical and
horizontal orientation. Incremental saddle encoders 191 are
preferably provided within each workpiece cassette turnstile 40 for
providing position information of the saddles 45, 46 to the
respective slave processor 170.
[0159] Either slave processor 170 or servo controller 175 may be
configured to control the operation of the workpiece cassette
elevator 42 for transferring a workpiece cassette 16 between either
the exchange position and the extraction position. The slave
processor 170 may be coupled with an elevator lift motor 187 and
elevator rotation motor 188 for controlling the elevation and
rotation of elevator 42 and elevator support 47. Incremental lift
encoder 192 and incremental rotation encoder 193 may supply
elevation and rotation information of the elevator 42 and support
47 to slave processor 170.
[0160] Absolute encoders 199 may be utilized to notify slave
processor of extreme conditions such as when elevator support 47
reaches a maximum height. Elevator lift motor 187 may be shut down
in response to the presence of an extreme condition by absolute
encoder 199.
[0161] Methods
[0162] Additional aspects of this invention include novel methods
of handling semiconductor workpieces W within a semiconductor
workpiece processing tool 10. The method of handling semiconductor
workpieces within a processing tool 10 having at least one
workpiece processing module 19 and a workpiece conveyor 60 includes
a step of receiving a workpiece cassette 16 having a plurality of
semiconductor workpieces W therein into the workpiece processing
tool 10. The method additionally includes steps of simultaneously
moving a first and second workpiece transport unit 62, 64 along the
workpiece conveyor 60 to simultaneously transport individual
semiconductor workpieces W between the workpiece cassettes 16 and
processing modules 19.
[0163] The workpiece cassette 16 may be preferably translated or
otherwise reoriented between an approximately vertical orientation
and an approximately horizontal orientation within the workpiece
processing tool 10. Specifically, each workpiece cassette 16 and
the semiconductor workpieces W therein are preferably oriented in a
vertical position during the step of loading the workpiece cassette
16 into the processing tool 10 or removing a workpiece cassette 16
therefrom. The workpiece cassettes 16 and semiconductor workpieces
therein are preferably oriented in a horizontal position during the
step of extracting semiconductor workpieces W from the workpiece
cassette 16. Further, a plurality of workpiece cassettes 16 may be
stored within the processing tool 10 to limit the exposure of the
workspace 11 of the processing tool 10 to the surrounding clean
room environment.
[0164] The methods can also preferably provide for introducing
unprocessed semiconductor workpieces into a first interface module
38 for storage. Workpiece transport units 62, 64 may access the
unprocessed semiconductor workpieces within a workpiece cassette 16
held by the first interface module 38. Processed semiconductor
workpieces are preferably placed into workpiece cassettes 16 held
within the output processing module 39 for removal from the
processing tool 10.
[0165] The present invention additionally provides for a method of
handling semiconductor workpieces W within a processing tool 10
having a plurality of workpiece processing modules 19 adjacent
opposing sides of a workpiece conveyor 60. The processing modules
are preferably along both sides and are accessible by transport
units from either side of conveyor 60. In particular, the method
comprises the steps of receiving a workpiece cassette 16 into the
processing tool 10 and storing the workpiece cassette 16 therein.
The semiconductor workpieces may be individually transferred via
the workpiece conveyor 60 to selected workpiece processing modules
19.
[0166] The method may include a translation step where the
semiconductor workpiece cassettes 16 are advantageously positioned
in a vertical orientation for stability during the receiving step
and in a horizontal orientation during an extraction step to
facilitate access to the semiconductor workpieces within a
respective workpiece cassette 16. The workpiece transport units 62,
64 may access each workpiece processing module 19 adjacent opposing
sides of the workpiece conveyor 60 to transfer the semiconductor
workpieces therebetween. Preferably, each workpiece transport unit
62, 64 travels along paths defined by the workpiece conveyor
60.
[0167] The method preferably provides for introducing unprocessed
semiconductor workpieces into a first interface module 38 for
storage and placing processed semiconductor workpieces into
workpiece cassettes 16 held within the output processing module 39
for temporary storage and removal from the processing tool 10.
[0168] Workpiece Support
[0169] Turning now to FIG. 22, a semiconductor processing machine
400 having two workpiece supports 401 is shown. Workpiece support
402 is shown in a "open" or "receive wafer" position in order to
receive a workpiece or semiconductor wafer for further processing.
Workpiece support 403 is shown in a "closed" or "deployed" position
wherein the semiconductor wafer has been received by the workpiece
support and is being exposed to the semiconductor manufacturing
process in the semiconductor manufacturing chamber 404. FIG. 1 also
shows an optional beam emitter 81 for emitting a laser beam
detected by robotic wafer conveyors to indicate position of the
unit.
[0170] Turning now to FIG. 23, an enlarged view of the workpiece
support 401 is shown. Workpiece support 401 advantageously includes
operator base 405, a processing head 406, and an operator arm 407.
Processing head 406 preferably includes workpiece holder or wafer
holder 408 and which further includes fingers 409 for securely
holding the workpiece during further process and manufacturing
steps. Workpiece holder 408 more preferably spins about workpiece
spin axis 410.
[0171] The processing head is advantageously rotatable about
processing head pivot axis or, more briefly termed, process pivot
axis 411. In this manner, a workpiece (not shown) may be disposed
between and grasped by the fingers 409, at which point the
processing head is preferably rotated about process head pivot axis
411 to place the workpiece in a position to be exposed to the
manufacturing process.
[0172] In the preferred embodiment, operator arm 407 may be pivoted
about operator pivot axis 412. In this manner, the workpiece is
advantageously lowered into the process bowl (not shown) to
accomplish a step in the manufacture of the semiconductor
wafer.
[0173] Turning now to FIGS. 24-26, the sequence of placing a
workpiece on the workpiece support and exposing the workpiece to
the semiconductor manufacturing process is shown. In FIG. 24, a
workpiece W is shown as being held in place by fingertips 414 of
fingers 409. Workpiece W is grasped by fingertips 414 after being
placed in position by robot or other means.
[0174] Once the workpiece W has been securely engaged by fingertips
414, processing head 406 can be rotated about process head pivot
axis 411 as shown in FIG. 25. Process head 406 is preferably
rotated about axis 411 until workpiece W is at a desired angle,
such as approximately horizontal. The operator arm 407 is pivoted
about operator arm pivot axis 412 in a manner so as to coordinate
the angular position of processing head 406. In the closed
position, the processing head is placed against the rim of bowl 416
and the workpiece W is essentially in a horizontal plane. Once the
workpiece W has been secured in this position, any of a series of
various semiconductor manufacturing process steps may be applied to
the workpiece as it is exposed in the processing bowl 417.
[0175] Since the processing head 406 is engaged by the operator arm
407 on the left and right side by the preferably horizontal axis
411 connecting the pivot points of processing head 406, a high
degree of stability about the horizontal plane is obtained.
Further, since the operator arm 407 is likewise connected to the
operator base 405 at left and right sides along the essentially
horizontal line 412 connecting the pivot points of the operator
arm, the workpiece support forms a structure having high rigidity
in the horizontal plane parallel to and defined by axes 411 and
412. Finally, since operator base 405 is securely attached to the
semiconductor process machine 400, rigidity about the spin axis 410
is also achieved.
[0176] Similarly, since processing head 406 is nested within the
fork or yoke shaped operator arm 407 having left and right forks
418 and 419, respectively, as shown in FIG. 23, motion due to
cantilevering of the processing head is reduced as a result of the
reduced moment arm defined by the line connecting pivot axes 411
and 412.
[0177] In a typical semiconductor manufacturing process, the
workpiece holder 408 will rotate the workpiece, having the process
head 406 secured at two points, that is, at the left and right
forks 418 and 419, respectively, the vibration induced by the
rotation of the workpiece holder 408 will be significantly reduced
along the axis 411.
[0178] A more complete description of the components of the present
invention and their operation and interrelation follows.
[0179] Operator Base
[0180] Turning now to FIG. 30, operator base 405 is shown. The
present invention advantageously includes an operator base 405
which forms an essentially yoke-shaped base having an operator base
back portion 420, an operator base left yoke arm 421, and an
operator base right yoke arm 422. Yoke arms 421 and 422 are
securely connected to the base of the yoke 420. In the preferred
embodiment, the yoke arms are secured to the yoke base by the yoke
arm fasteners 423. The yoke arm base in turn is advantageously
connected to the semiconductor process machine 400 as shown in FIG.
22.
[0181] The upper portions of the yoke arm advantageously include
receptacles for housing the operator arm bearings 424 which are
used to support the pivot shafts of the operator arm 425, described
more fully below.
[0182] Operator Arm
[0183] Still viewing FIG. 30, the present invention advantageously
includes an operator arm 407. As described previously, operator arm
407 preferably pivots about the operator arm pivot axis 412 which
connects the center line defined by the centers of operator arm
pivot bearings 424.
[0184] Operator arm or pivot arm 407 is advantageously constructed
in such a manner to reduce mass cantilevered about operator arm
pivot axis 412. This allows for quicker and more accurate
positioning of the pivot arm as it is moved about pivot arm axis
412.
[0185] The left fork of the pivot arm 418, shown more clearly in
FIG. 32, houses the mechanism for causing the pivot arm to lift or
rotate about pivot arm pivot axis 412. Pivot arm right fork 419,
shown more clearly in FIG. 31, houses the mechanism for causing the
processing head 406 (not shown) to rotate about the process head
pivot axis 411.
[0186] The process arm rear cavity 426, shown in FIG. 30, houses
the lift motor 452 for causing the operator arm 407 to rotate about
pivot arm axis 412. Process arm rear cavity 426 also houses rotate
motor 428 which is used to cause the processing head 406 to rotate
about the processing head pivot axis 411. The rotate motor 428 may
more generally be described as a processing head pivot or rotate
drive. Processing head 406 is mounted to operator arm 407 at
processing head left pivot shaft 429 and processing head right
pivot shaft 430.
[0187] Operator arm 407 is securely attached to left yoke arm 421
and right yoke arm 422 by operator arm pivot shafts 425 and
operator arm pivot bearings 424, the right of which such bearing
shaft and bearings are shown in FIG. 30.
[0188] Operator Arm-Processing Head Rotate Mechanism
[0189] Turning now to FIG. 34, a sectional plan view of the right
rear corner of operator arm 407 is shown. The right rear section of
operator arm 407 advantageously contains the rotate mechanism which
is used to rotate processing head 406 about processing head pivot
shafts 430 and 429. Processing head rotate mechanism 431 preferably
consists of rotate motor 428 which drives rotate shaft 432, more
generally described as a processing head drive shaft. Rotate shaft
432 is inserted within rotate pulley 425 which also functions as
the operator arm pivot shaft. As described previously, the operator
arm pivot shaft/lift pulley is supported in operator arm pivot
bearings 424, which are themselves supported in operator base yoke
arm 422. Rotate shaft 432 is secured within left pulley 424 by
securing collar 433. Securing collar 433 secures rotate pulley 425
to rotate shaft 432 in a secure manner so as to assure a positive
connection between rotate motor 428 and rotate pulley 425. An inner
cover 584 is also provided.
[0190] Rotate motor 428 is disposed within process arm rear cavity
426 and is supported by rotate motor support 434. Rotate motor 428
preferably is a servo allowing for accurate control of speed and
acceleration of the motor. Servo motor 428 is advantageously
connected to rotate encoder 435 which is positioned on one end of
rotate motor 428. Rotate encoder 435, more generally described as
processing head encoder, allows for accurate measurement of the
number of rotations of rotate motor 428, as well as the position,
speed, and acceleration of the rotate shaft 432. The information
from the rotate encoder may be used in a rotate circuit which may
then be used to control the rotate motor when the rotate motor is a
servo. This information is useful in obtaining the position and
rate of travel of the processing head, as well as controlling the
final end point positions of the processing head as it is rotated
about process head rotate axis 411.
[0191] The relationship between the rotate motor rotations, as
measured by rotate encoder 435, may easily be determined once the
diameters of the rotate pulley 425 and the processing head pulley
438 are known. These diameters can be used to determine the ratio
of rotate motor relations to processing head rotations. This may be
accomplished by a microprocessor, as well as other means.
[0192] Rotate pulley 425 is further supported within operator arm
407 by rotate pulley inboard bearing 436 which is disposed about an
extended flange on the rotate pulley 425. Rotate pulley inboard
bearing 436 is secured by the body of the operator arm 407, as
shown in FIG. 34.
[0193] Rotate pulley 425 advantageously drives rotate belt 437,
more generally described as a flexible power transmission coupling.
Referring now to FIG. 31, rotate belt 437 is shown in the side view
of the right arm 419 of the operator arm 407. Rotate belt 437 is
preferably a toothed timing belt to ensure positive engagement with
the processing head drive wheel, more particularly described herein
as the processing head pulley 438, (not shown in this view). In
order to accommodate the toothed timing belt 437, both the rotate
pulley 425 and the processing head pulley 438 are advantageously
provided with gear teeth to match the tooth pattern of the timing
belt to assure positive engagement of the pulleys with the rotate
belt.
[0194] Rotate mechanism 431 is preferably provided with rotate belt
tensioner 439, useful for adjusting the belt to take up slack as
the belt may stretch during use, and to allow for adjustment of the
belt to assure positive engagement with both the rotate pulley and
the processing head pulley. Rotate belt tensioner 439 adjusts the
tension of rotate belt 437 by increasing the length of the belt
path between rotate pulley 425 and processing head pulley 438,
thereby accommodating any excess lengths in the belt. Inversely,
the length of the belt path may also be shortened by adjusting
rotate belt tensioner 439 so as to create a more linear path in the
upper portion of rotate belt 437. The tensioner 439 is adjusted by
rotating it about tensioner hub 468 and securing it in a new
position.
[0195] Turning now to FIG. 34, processing head pulley 438 is
mounted to processing head rotate shaft 430 in a secured manner so
that rotation of processing head pulley 438 will cause processing
head rotate shaft 430 to rotate. Processing head shaft 430 is
mounted to operator arm right fork 419 by processing head shaft
bearing 440, which in turn is secured in the frame of the right
fork 419 by processing head rotate bearing 469. In a like manner,
processing head shaft 429 is mounted in operator arm left fork 418
by processing head shaft bearing 441, as shown in FIG. 30.
[0196] Processing head pivot shafts 430 and 429 are advantageously
hollow shafts. This feature is useful in allowing electrical,
optical, pneumatic, and other signal and supply services to be
provided to the processing head. Service lines such as those just
described which are routed through the hollow portions of
processing head pivot shafts 429 and 430 are held in place in the
operator arms by cable brackets 442 and 443. Cable brackets 442 and
443 serve a dual purpose. First, routing the service lines away
from operating components within the operator arm left and right
forks. Second, cable brackets 442 and 443 serve a useful function
in isolating forces imparted to the service cables by the rotating
action of processing head 406 as it rotates about processing head
pivot shafts 429 and 430. This rotating of the processing head 406
has the consequence that the service cables are twisted within the
pivot shafts as a result of the rotation, thereby imparting forces
to the cables. These forces are preferably isolated to a particular
area so as to minimize the effects of the forces on the cables. The
cable brackets 442 and 443 achieve this isolating effect.
[0197] The process head rotate mechanism 431, shown in FIG. 34, is
also advantageously provided with a rotate overtravel protect 444,
which functions as a rotate switch. Rotate overtravel protect 444
preferably acts as a secondary system to the rotate encoder 435
should the control system fail for some reason to stop servo 428 in
accordance with a predetermined position, as would be established
by rotate encoder 435. Turning to FIG. 34, the rotate overtravel
protect 444 is shown in plan view. The rotate overtravel protect
preferably consists of rotate optical switches 445 and 446, which
are configured to correspond to the extreme (beginning and end
point) portions of the processing head, as well as the primary
switch component which preferably is a rotate flag 447. Rotate flag
447 is securely attached to processing head pulley 438 such that
when processing head shaft 430 (and consequently processing head
406) are rotated by virtue of drive forces imparted to the
processing head pulley 425 by the rotate belt 437, the rotate flag
447 will rotate thereby tracking the rotate motion of processing
head 406. Rotate optical switches 445 and 446 are positioned such
that rotate flag 447 may pass within the optical path generated by
each optical switch, thereby generating a switch signal. The switch
signal is used to control an event such as stopping rotate motor
428. Rotate optical switch 445 will guard against overtravel of
processing head 406 in one direction, while rotate optical switch
446 will provide against overtravel of the processing head 406 in
the opposite direction.
[0198] Operator Arm-Lift Mechanism
[0199] Operator arm 407 is also advantageously provided with an
operator arm lift mechanism 448 which is useful for causing the
operator arm to lift, that is, to pivot or rotate about operator
arm pivot axis 412. Turning to FIG. 35, the operator arm lift
mechanism 448 is shown in the sectional plan view of the right rear
corner of operator arm 407.
[0200] Operator arm lift mechanism 448 is advantageously driven by
lift motor 452. Lift motor 452 may be more generally described as
an operator arm drive or operator arm pivot drive. Lift motor 452
is preferably a servo motor and is more preferably provided with an
operator encoder, more specifically described as lift motor encoder
456. When lift motor 452 is a servo motor coupled with lift encoder
456, information regarding the speed and absolute rotational
position of the lift motor shaft 454 may be known from the lift
encoder signal. Additionally, by virtue of being a servo mechanism,
the angular speed and acceleration of lift motor 452 may be easily
controlled by use of the lift signal by an electrical circuit. Such
a lift circuit may be configured to generate desired lift
characteristics (speed, angle, acceleration, etc.). FIG. 14 shows
that the lift operator may also include a brake 455 which is used
to safely stop the arm if power fails.
[0201] Lift motor 452 drives lift motor shaft 454 which in turn
drives lift gear drive 453. Lift gear drive 453 is a gear reduction
drive to produce a reduced number of revolutions at lift drive
shaft 456 as the function of input revolutions from lift motor
shaft 454.
[0202] Lift drive gear shaft 456 is secured to lift anchor 451
which is more clearly shown in FIG. 32. Lift anchor 451 is
preferably shaped to have at least one flat side for positively
engaging lift bushing 449. Lift anchor 451 is secured to lift drive
shaft 456 by anchor plate 458 and anchor fasteners 457. In this
manner, when lift drive shaft 456 is rotated, it will positively
engage lift bushing 449. Returning to FIG. 35, it is seen that lift
bushing 449 is mounted in operator left yoke arm 421, and is thus
fixed with respect to operator base 405. Lift bearing 450 is
disposed about the lift bushing shank and is supported in operator
arm 407 by lift bearing support 460 which is a bushing configured
to receive lift bearing 450 on a first end and to support lift gear
drive 453 on a second end. Lift bearing support 460 is further
supported within operator arm 407 by operator arm frame 461. The
lift arm is thus free to pivot about lift bushing 449 by virtue of
lift bearing 450.
[0203] In operation, as lift motor 452 causes lift gear drive 453
to produce rotations at gear drive shaft 456, lift anchor 451 is
forced against lift bushing 449 which is securely positioned within
right operator yoke arm 421. The reactive force against the lift
anchor 451 will cause lift bearing support 460 to rotate relative
to lift bushing 449. Since lift bushing 449 is fixed in operator
base 405, and since operator base 405 is fixed to processing
machine 400, rotation of lift bearing support 460 will cause lift
arm 407 to pivot about operator arm pivot axis 412, thereby moving
the processing head 406. It is advantageous to consider the gear
drive shaft (or "operator arm shaft") as being fixed with respect
to operator base 405 when envisioning the operation of the lift
mechanism.
[0204] Operator lift mechanism 448 is also advantageously provided
with a lift overtravel protect 462 or lift switch. The lift rotate
protect operates in a manner similar to that described for the
rotate overtravel protect 444 described above. Turning now to FIG.
32, a left side view of the operator arm 407 is shown which shows
the lift overtravel protect in detail.
[0205] The lift overtravel protect preferably includes a lift
optical switch low 463 and a lift optical switch high 464. Other
types of limit switches can also be used. The switch high 464 and
switch low 463 correspond to beginning and endpoint travel of lift
arm 407. The primary lift switch component is lift flag 465, which
is firmly attached to left operator base yoke arm 421. The lift
optical switches are preferably mounted to the movable operator arm
407. As operator arm 407 travels in an upward direction in pivoting
about operator arm pivot axis 412, lift optical switch high 464
will approach the lift flag 465. Should the lift motor encoder 455
fail to stop the lift motor 454 as desired, the lift flag 465 will
break the optical path of the lift optical switch high 464 thus
producing a signal which can be used to stop the lift motor. In
like manner, when the operator arm 407 is being lowered by rotating
it in a clockwise direction about the operator arm pivot axis 412,
as shown in FIG. 32, overtravel of operator arm 407 will cause lift
optical switch low 463 to have its optical path interrupted by lift
flag 465, thus producing a signal which may be used to stop lift
motor 452. As is shown in FIG. 32, lift flag 465 is mounted to left
operator base yoke arm 421 with slotted lift flag mounting slots
467 and removable lift flag fasteners 466. Such an arrangement
allows for the lift flag to be adjusted so that the lift overtravel
protect system only becomes active after the lift arm 407 has
traveled beyond a preferred point.
[0206] Processing Head
[0207] Turning now to FIG. 27, a front elevation schematic view of
the processing head 406 is shown. Processing head 406 is described
in more detail in FIGS. 28 and 29. Turning now to FIG. 28, a
sectional view of the left front side of processing head 406 is
shown. Processing head 406 advantageously includes a processing
head housing 470 and frame 582. Processing head 406 is preferably
round in shape in plan view allowing it to easily pivot about
process head pivot axis 411 with no interference from operator arm
407, as demonstrated in FIGS. 24-26. Returning to FIG. 28,
processing head housing 470 more preferably has circumferential
grooves 471 which are formed into the side of process head housing
470. Circumferential grooves 471 have a functional benefit of
increasing heat dissipation from processing head 406.
[0208] The sides of processing head housing 470 are advantageously
provided with rotate shaft openings 474 and 475 for receiving
respectively left and right processing head pivot shafts 429 and
430. Processing head pivot shafts 429 and 430 are secured to the
processing head 406 by respective left and right processing head
mounts 472 and 473. Processing head mounts 472 and 473 are
affirmative connected to processing head frame 582 which also
supports processing head door 476 which is itself securely fastened
to processing head housing 470. Consequently, processing head pivot
shafts 429 and 430 are fixed with respect to processing head 407
and may therefore rotate or pivot with respect to operator arm 407.
The details of how processing head pivot shafts 429 and 430 are
received within operator arm 407 were discussed supra.
[0209] Processing head housing 470 forms a processing head void 477
which is used to house additional processing head components such
as the spin motor, the pneumatic finger actuators, and service
lines, all discussed more fully below.
[0210] The processing head also advantageously includes a workpiece
holder and fingers for holding a workpiece, as is also more fully
described below.
[0211] Processing Head Spin Motor
[0212] In a large number of semiconductor manufacturing processes,
is desirable to spin the semiconductor wafer or workpiece during
the process, for example to assure even distribution of applied
process fluids across the face of the semiconductor wafer, or to
aid drying of the wafer after a wet chemistry process. It is
therefore desirable to be able to rotate the semiconductor
workpiece while it is held by the processing head.
[0213] The semiconductor workpiece is held during the process by
workpiece holder 478 described more fully below. In order to spin
workpiece holder 478 relative to processing head 406 about spin
axis 479, an electric, pneumatic, or other type of spin motor or
workpiece spin drive is advantageously provided.
[0214] Turning to FIG. 29, spin motor 480 has armatures 526 which
drive spin motor shaft 483 in rotational movement to spin workpiece
holder 478. Spin motor 480 is supported by bottom motor bearing 492
in bottom motor housing 482. Bottom motor housing 482 is secured to
processing head 406 by door 476. Spin motor 480 is thus free to
rotate relative to processing head housing 470 and door 476. Spin
motor 480 is preferably additionally held in place by top motor
housing 481 which rests on processing head door 476. Spin motor 480
is rotationally isolated from top motor housing 481 by top motor
bearing 493, which is disposed between the spin motor shaft 483 and
top motor housing 481.
[0215] The spin motor is preferably an electric motor which is
provided with an electrical supply source through pivot shaft 429
and/or 430. Spin motor 480 will drive spin motor shaft 483 about
spin axis 479.
[0216] To secure workpiece holder rotor 484 to spin motor shaft
483, workpiece holder rotor 484 is preferably provided with a rotor
hub 485. Rotor hub 485 defines a rotor hub recess 486 which
receives a flared end of workpiece holder shaft 491. The flared end
487 of workpiece holder shaft 491 is secured within the rotor hub
recess 486 by workpiece shaft snap-ring 488 which fits within rotor
recess groove 489 above the flared portion 487 of workpiece holder
shaft 491.
[0217] The workpiece holder shaft 491 is fitted inside of spin
motor shaft 483 and protrudes from the top of the spin motor shaft.
The top of workpiece holder shaft 491 is threaded to receive thin
nut 527 (see FIG. 28). Thin nut 527 is tightened against optical
tachometer 499 (describe more fully below). Optical tachometer 499
is securely attached to spin motor shaft 483 such that as the spin
motor 480 rotationally drives the spin motor shaft 483, the
workpiece holder shaft 491 is also driven.
[0218] Workpiece holders may be easily changed out to accommodate
various configurations which may be required for the various
processes encountered in manufacturing of the semiconductors. This
is accomplished by removing spin encoder 498 (described below), and
then thin nut 527. Once the thin nut has been removed the workpiece
holder 478 will drop away from the processing head 406.
[0219] The processing head is also advantageously provided with a
spin encoder 498, more generally described as a workpiece holder
encoder, and an optical tachometer 499. As shown in FIG. 28, spin
encoder 498 is mounted to top motor housing 481 by encoder support
528 so as to remain stationary with respect to the processing head
406. Optical tachometer 499 is mounted on spin motor shaft 483 so
as to rotate with the motor 480. When operated in conjunction, the
spin encoder 498 and optical tachometer 499 allow the speed,
acceleration, and precise rotational position of the spin motor
shaft (and therefore the workpiece holder 478) to be known. In this
manner, and when spin motor 480 is provided as a servo motor, a
high degree of control over the spin rate, acceleration, and
rotational angular position of the workpiece with respect to the
process head 407 may be obtained.
[0220] In one application of the present invention the workpiece
support is used to support a semiconductor workpiece in an
electroplating process. To accomplish the electroplating an
electric current is provided to the workpiece through an alternate
embodiment of the fingers (described more fully below). To provide
electric current to the finger, conductive wires are run from the
tops of the fingers inside of the workpiece holder 478 through the
electrode wire holes 525 in the flared lower part of workpiece
holder shaft 491. The electrode wires are provided electric current
from electrical lines run through processing pivot shaft 429 and/or
430.
[0221] The electrical line run through pivot shaft 430/429 will by
nature be stationary with respect to processing head housing 470.
However, since the workpiece holder rotor is intended to be capable
of rotation during the electroplating process, the wires passing
into workpiece support shaft 491 through electrode wire holes 525
may rotate with respect to processing head housing 470. Since the
rotating electrode wires within workpiece shaft 491 and the
stationary electrical supply lines run through pivot shaft 430/429
must be in electrical communication, the rotational/stationary
problem must be overcome. In the preferred embodiment, this is
accomplished by use of electrical slip ring 494.
[0222] Electrical slip ring 494, shown in FIG. 28, has a lower wire
junction 529 for receiving the conductive ends of the electrical
wires passing into workpiece holder shaft 491 by electrode wire
holes 525. Lower wire junction 529 is held in place within
workpiece holder shaft 491 by insulating cylindrical collar 497 and
thus rotates with spin motor shaft 483. The electrode wires
terminate in a single electrical contact 531 at the top of the
lower wire junction 529. Electrical slip ring 494 further has a
contact pad 530 which is suspended within the top of workpiece
holder shaft 491. Contact pad 530 is mechanically fastened to spin
encoder 498, which, as described previously, remains stationary
with respect to processing head housing 470. The stationary to
rotational transition is made at the tip of contact pad 530, which
is in contact with the rotating electrical contact 531. Contact pad
530 is electrically conductive and is in electrical communication
with electrical contact 531. In the preferred embodiment, contact
pad 530 is made of copper-beryllium. A wire 585 carries current to
finger assemblies when current supply is needed, such as on the
alternative embodiment described below.
[0223] Processing Head Finger Actuators
[0224] Workpiece holder 478, described more fully below,
advantageously includes fingers for holding the workpiece W in the
workpiece holder, as shown in FIGS. 28 and 29. Since the workpiece
holder 478 may be removed as described above, it is possible to
replace one style of workpiece holder with another. Since a variety
of workpiece holders with a variety of fingers for holding the
workpiece is possible, it is desirable to have a finger actuator
mechanism disposed within processing head 407 which is compatible
with any given finger arrangement. The invention is therefore
advantageously provided with a finger actuator mechanism.
[0225] Turning to FIG. 28, a finger actuator mechanism 500 is
shown. Finger actuator mechanism 500 is preferably a pneumatically
operated mechanism. A pneumatic cylinder is formed by a cavity 501
within top motor housing 481. Pneumatic piston 502 is disposed
within cavity 501. Pneumatic piston 502 is biased in an upward
position within cavity 501 by actuator spring 505. Actuator spring
505 is confined within cavity 501 by cavity end cap 507, which is
itself constrained by retaining ring 508. Pneumatic fluid is
provided to the top of pneumatic piston 502 via pneumatic inlet
503. Pneumatic fluid is provided to pneumatic inlet 503 by
pneumatic supply line 504 which is routed through processing head
pivot shaft 429 and hence through the left fork 418 of the operator
arm 407. Turning to FIG. 29, it can be seen that a second pneumatic
cylinder which is identical to the pneumatic cylinder just
described is also provided.
[0226] Pneumatic piston 502 is attached to actuator plate 509 by
actuator plate connect screw 510. Wave springs 529 provide
flexibility to the connecting at screws 510. Actuator plate 509 is
preferably an annular plate concentric with the spin motor 580 and
disposed about the bottom motor housing 482, and is symmetrical
about spin axis 479. Actuator plate 509 is secured against
pneumatic piston 502 by bushing 512 which is disposed in pneumatic
piston recess 511 about pneumatic piston 502. Bushing 512 acts as a
support for wave springs 529 to allow a slight tilting of the
actuator plate 509. Such an arrangement is beneficial for providing
equal action against the finger actuator contracts 513 about the
entire actuator plate or ring 509.
[0227] When pneumatic fluid is provided to the space above the
pneumatic piston 502, the pneumatic piston 502 travels in a
downward direction compressing actuator spring 505. As pneumatic
piston 502 travels downward, actuator plate 509 is likewise pushed
downward by flexible bushing 512. Actuator plate 509 will contact
finger actuator contacts 513 causing the fingers to operate as more
fully described below.
[0228] Actuator seals 506 are provided to prevent pneumatic gas
from bypassing the top of the pneumatic piston 502 and entering the
area occupied by actuator spring 505.
[0229] Processing Head Workpiece Holder
[0230] Workpiece holder 478 is used to hold the workpiece W, which
is typically a semiconductor wafer, in position during the
semiconductor manufacturing process.
[0231] Turning now to FIG. 29, a finger 409 is shown in cross
section. Finger 409 advantageously includes a finger actuator
contact 513 which is contacted by actuator plate 509, as described
above. Finger actuator contact 513 is connected to finger actuator
lever 514 (more generally, "finger extension") which is
cantilevered from and connected to the finger stem 515. Finger stem
515 is inserted into finger actuator lever 514. Disposed about the
portion of the finger actuator lever which encompasses and secures
finger stem 515 is finger diaphragm 519. Finger diaphragm 519 is
preferably made of a flexible material such as Tetrafluoroethylene,
also known as Teflon.RTM. (registered trademark of E.I. DuPont de
Nemours Company). Finger 409 is mounted to workpiece holder rotor
484 using finger diaphragm 519. Finger diaphragm 519 is inserted
into the finger opening 521 in rotor 484. The finger diaphragm 519
is inserted into the rotor from the side opposite that to which the
workpiece will be presented. Finger diaphragm 519 is secured to
rotor 484 against rotor diaphragm lip 523. Forces are intentionally
imparted as a result of contact between the actuator plate 509 and
the finger actuator contact 513 when the finger actuator mechanism
500 is actuated.
[0232] Finger actuator lever 514 is advantageously biased in a
horizontal position by finger spring 520 which acts on finger
actuator tab 522 which in turn is connected to finger actuator
lever 514. Finger spring 520 is preferably a torsion spring secured
to the workpiece holder rotor 484.
[0233] Finger stem 515 is also preferably provided with finger
collar or nut 517 which holds the finger stem 515 against shoulder
518. Finger collar 517 threads or otherwise securely fits over the
lower end of finger actuator lever 514. Below the finger collar
517, finger stem 515 extends for a short distance and terminates in
fingertip 414. Fingertip 414 contains a slight groove or notch
which is beneficially shaped to receive the edge of the workpiece
W.
[0234] In actuation, finger actuator plate 509 is pushed downward
by finger actuator mechanism 500. Finger actuator plate 509
continues its downward travel contacting finger actuator contacts
513. As actuator plate 509 continues its downward travel, finger
actuator contacts are pushed in a downward direction. As a result
of the downward direction, the finger actuator levers 514 are
caused to pivot.
[0235] In the preferred embodiment, a plurality of fingers are used
to hold the workpiece. In one example, six fingers were used. Once
the actuator plate 509 has traveled its full extent, the finger
stems 515 will be tilted away from the spin axis 479. The
circumference described by the fingertips in this spread-apart
position should be greater than the circumference of the workpiece
W. Once a workpiece W has been positioned proximate to the
fingertips, the pneumatic pressure is relieved on the finger
actuator and the actuator spring 505 causes the pneumatic piston
502 to return to the top of the cavity 501. In so doing, the
actuator plate 509 is retracted and the finger actuator levers are
returned to their initial position by virtue of finger springs
520.
[0236] Semiconductor Workpiece Holder--Electroplating
Embodiment
[0237] FIG. 36 is a side elevational view of a semiconductor
workpiece holder 810 constructed according to a preferred aspect of
the invention.
[0238] Workpiece holder 810 is used for processing a semiconductor
workpiece such as a semiconductor wafer shown in phantom at W. One
preferred type of processing undertaken with workpiece holder 810
is a workpiece electroplating process in which a semiconductor
workpiece is held by workpiece holder 810 and an electrical
potential is applied to the workpiece to enable plating material to
be plated thereon. Such can be, and preferably is accomplished
utilizing a processing enclosure or chamber which includes a bottom
half or bowl 811 shown in phantom lines in FIG. 1. Bottom half 811
together with workpiece holder 810 forms a sealed, protected
chamber for semiconductor workpiece processing. Accordingly,
preferred reactants can be introduced into the chamber for further
processing. Another preferred aspect of workpiece holder 810 is
that such moves, rotates or otherwise spins the held workpiece
during processing as will be described in more detail below.
[0239] Processing Head and Processing Head Operator
[0240] Turning now to FIG. 36, semiconductor workpiece holder 810
includes a workpiece support 812. Workpiece support 812
advantageously supports a workpiece during processing. Workpiece
support 812 includes a processing head or spin head assembly 814.
Workpiece support 812 also includes a head operator or lift/rotate
assembly 816. Spin head assembly 814 is operatively coupled with
lift/rotate assembly 816. Spin head assembly 814 advantageously
enables a held workpiece to be spun or moved about a defined axis
during processing. Such enhances conformal coverage of the
preferred plating material over the held workpiece. Lift/rotate
assembly 816 advantageously lifts spin head assembly 814 out of
engagement with the bottom half 811 of the enclosure in which the
preferred processing takes place. Such lifting is preferably about
an axis x.sub.1. Once so lifted, lift/rotate assembly 816 also
rotates the spin head and held workpiece about an axis x.sub.2 so
that the workpiece can be presented face-up and easily removed from
workpiece support 812. In the illustrated and preferred embodiment,
such rotation is about 180.degree. from the disposition shown in
FIG. 36. Advantageously, a new workpiece can be fixed or otherwise
attached to the workpiece holder for further processing as
described in detail below.
[0241] The workpiece can be removed from or fixed to workpiece
holder 810 automatically by means of a robotically controlled arm.
Alternatively, the workpiece can be manually removed from or fixed
to workpiece holder 810. Additionally, more than one workpiece
holder can be provided to support processing of multiple
semiconductor workpieces. Other means of removing and fixing a
semiconductor workpiece are possible.
[0242] FIG. 37 is a front sectional view of the FIG. 36
semiconductor workpiece holder. As shown, workpiece support 812
includes a motor 818 which is operatively coupled with a rotor 820.
Rotor 820 is advantageously mounted for rotation about a rotor spin
axis 822 and serves as a staging platform upon which at least one
finger assembly 824 is mounted. Preferably, more than one finger
assembly is mounted on rotor 820, and even more preferably, four or
more such finger assemblies are mounted thereon and described in
detail below although only two are shown in FIG. 37. The preferred
finger assemblies are instrumental in fixing or otherwise holding a
semiconductor workpiece on semiconductor workpiece holder 810. Each
finger assembly is advantageously operatively connected or
associated with a actuator 825. The actuator is preferably a
pneumatic linkage which serves to assist in moving the finger
assemblies between a disengaged position in which a workpiece may
be removed from or added to the workpiece holding, and an engaged
position in which the workpiece is fixed upon the workpiece holder
for processing. Such is described in more detail below.
[0243] FIG. 38 is a top or plan view of rotor 820 which is
effectively taken along line 3-3 in FIG. 37. FIG. 37 shows the
preferred four finger assemblies 824. As shown, rotor 820 is
generally circular and resembles from the top a spoked wheel with a
nearly continuous bottom surface. Rotor 820 includes a rotor center
piece 826 at the center of which lies rotor axis 822. A plurality
of struts or spokes 828 are joined or connected to rotor center 826
and extend outwardly to join with and support a rotor perimeter
piece 830. Advantageously, four of spokes 828 support respective
preferred finger assemblies 824. Finger assemblies 824 are
advantageously positioned to engage a semiconductor workpiece, such
as a wafer W which is shown in phantom lines in the position such
would occupy during processing. When a workpiece is so engaged, it
is fixedly held in place relative to the rotor so that processing
can be effected. Such processing can include exposing the workpiece
to processing conditions which are effective to form a layer of
material on one or more surfaces or potions of a wafer or other
workpiece. Such processing can also include moving the workpiece
within a processing environment to enhance or improve conformal
coverage of a layering material. Such processing can, and
preferably does include exposing the workpiece to processing
conditions which are effective to form an electroplated layer on or
over the workpiece.
[0244] Finger Assembly
[0245] Referring now to FIGS. 39-41, various views of a preferred
finger assembly are shown. The preferred individual finger
assemblies are constructed in accordance with the description
below. FIG. 39 is an isolated side sectional view of a finger
assembly constructed in accordance with a preferred aspect of the
invention. FIG. 40 is a side elevational view of the finger
assembly turned 90.degree. from the view of FIG. 39. FIG. 41 is a
fragmentary cross-sectional enlarged view of a finger assembly and
associated rotor structure. The finger assembly as set forth in
FIGS. 39 and 40 is shown in the relative position such as it would
occupy when processing head or spin head assembly 814 (FIGS. 36 and
37) is moved or rotated by head operator or lift/rotate assembly
816 into a position for receiving a semiconductor workpiece. The
finger assembly is shown in FIGS. 39 and 41 in an orientation of
about 180.degree. from the position shown in FIG. 41. This
typically varies because spin head assembly 814 is rotated
180.degree. from the position shown in FIGS. 36 and 37 in order to
receive a semiconductor workpiece. Accordingly, finger assemblies
824 would be so rotated. Lesser degrees of rotation are
possible.
[0246] Finger assembly 824 includes a finger assembly frame 832.
Preferably, finger assembly frame 832 is provided in the form of a
sealed contact sleeve which includes an angled slot 832a, only a
portion of which is shown in FIG. 40. Angled slot 832a
advantageously enables the finger assembly to be moved, preferably
pneumatically, both longitudinally and rotationally as will be
explained below. Such preferred movement enables a semiconductor
workpiece to be engaged, electrically contacted, and processed in
accordance with the invention.
[0247] Finger assembly frame 832 includes a finger assembly frame
outer flange 834 which, as shown in FIG. 41, engages an inner drive
plate portion 836 of rotor 820. Such engagement advantageously
fixes or seats finger assembly frame 832 relative to rotor 820.
Such, in turn, enables the finger assembly, or a portion thereof,
to be moved relative to the rotor for engaging the semiconductor
workpiece.
[0248] Finger Assembly Drive System
[0249] Referring to FIGS. 37 and 39-41, the finger assembly
includes a finger assembly drive system which is utilized to move
the finger assembly between engaged and disengaged positions. The
finger assembly drive system includes a bearing 838 and a collet
840 operatively adjacent the bearing. Bearing 838 includes a
bearing receptacle 839 for receiving a pneumatically driven source,
a fragmented portion of which is shown directly above the
receptacle in FIG. 41. The pneumatically driven source serves to
longitudinally reciprocate and rotate collet 840, and hence a
preferred portion of finger assembly 824. A preferred pneumatically
driven source is described below in more detail in connection with
the preferred longitudinal and rotational movement effectuated
thereby. Such longitudinal reciprocation is affected by a biasing
mechanism in the form of a spring 842 which is operatively mounted
between finger assembly frame 832 and a spring seat 844. The
construction develop a bias between finger assembly frame 832 and
spring seat 844 to bias the finger into engagement against a wafer.
Advantageously, the cooperation between the above mentioned
pneumatically driven source as affected by the biasing mechanism of
the finger assembly drive system, enable collet 840 to be
longitudinally reciprocated in both extending and retracting modes
of movement. As such, finger assembly 824 includes a biased portion
which is biased toward a first position and which is movable to a
second position away from the first position. Other manners of
longitudinally reciprocating the finger assembly are possible.
[0250] Finger Assembly Electrical System
[0251] Referring to FIGS. 37 and 40, the finger assembly preferably
includes a finger assembly electrical system which is utilized to
effectuate an electrical bias to a held workpiece and supply
electrical current relative thereto. The finger assembly electrical
system includes a pin connector 846 and a finger 848. Pin connector
846 advantageously provides an electrical connection to a power
source (not shown) via wire 585 and associate slip ring mechanism,
described above in connection with FIG. 28 and other Figs. This is
for delivering an electrical bias and current to an electrode which
is described below. Pin connector 846 also rides within angled slot
832a thereby mechanically defining the limits to which the finger
assembly may be both longitudinally and rotationally moved.
[0252] Finger 848 is advantageously fixed or secured to or within
collet 840 by a nut 850 which threadably engages a distal end
portion of collet 840 as shown best in FIG. 39. An anti-rotation
pin 852 advantageously secures finger 848 within collet 840 and
prevents relative rotation therebetween. Electrical current is
conducted from connector 846 through collet 840 to finger 860, all
of which are conductive, such as from stainless steel. The finger
and collet cain be coated with a suitable dielectric coating 856,
such as TEFLON or others. The collet 840 and finger member 860 are
in one form of the invention made hollow and tubular to conduct a
purge gas therethrough.
[0253] Finger assembly 824 may also optionally include a distal tip
or finger tip 854. Tip 854 may also have a purge gas passage formed
therethrough. Finger tip 854 advantageously engages against a
semiconductor workpiece (see FIG. 41) and assists in holding or
fixing the position of the workpiece relative to workpiece holder
810. Finger tip 854 also assists in providing an operative
electrical connection between the finger assembly and a workpiece
to which an electrical biased is to be applied and through which
current can move. Finger tip 85 can include an electrode contact
858 for electrically contacting a surface of a semiconductor
workpiece once such workpiece is secured as describe below.
[0254] Finger Assembly Drive System Interface
[0255] A finger assembly drive system interface is operatively
coupled with the finger assembly drive system to effectuate
movement of the finger assembly between the engaged and disengaged
positions. A preferred finger assembly drive system interface is
described with reference to FIGS. 37 and 41. One component of the
finger assembly drive system interface is a finger actuator 862.
Finger actuator 862 is advantageously provided for moving the
finger assembly between the engaged and disengaged position. Finger
actuator 862 acts by engaging bearing receptacle 839 and moving
finger assembly 824 between an engaged position and a disengaged
position. In the engaged position, finger tip 854 is engaged
against a semiconductor workpiece. In the disengaged position
finger tip 854 is moved away from the workpiece.
[0256] The finger assembly drive system interface includes
pneumatic actuator 825 (FIG. 37). Pneumatic actuators 825 are
operatively connected to an actuation ring 863 and operates
thereupon causing the drive plate to move reciprocally in the
vertical direction as viewed in FIG. 37. Finger actuator 862 is
operatively connected to actuation ring 863 in a manner which, upon
pneumatic actuation, moves the finger actuator into engagement with
bearing receptacle 839 along the dashed line in FIG. 41. Such
allows or enables the finger assembly to be moved longitudinally
along a first movement path axis 864.
[0257] Pneumatic actuator linkage 825 also includes a secondary
linkage 865. Secondary linkage 865 is pneumatic as well and
includes a link arm 867. Link arm 867 is connected or joined to an
actuator torque ring 869. Preferably, torque ring 869 is concentric
with rotor 820 (FIG. 38) and circuitously links each of the finger
actuators together. A pneumatic operator 871 is advantageously
linked with the secondary linkage 865 for applying force and
operating the linkage by angularly displacing torque ring 869. This
in turn rotates the finger assemblies into and away from the
engaged position.
[0258] Preferably finger actuator engagement bits 862, under the
influence of pneumatic linkage 825, moves the finger assembly, and
more specifically collet 840 and finger 848 along a first axial
movement path along axis 864. The finger actuator engagement bits
862, then under as the influence of pneumatic operator 871 are
turned about the axes of each bit like a screwdriver. This moves
collet 840 and finger 848 in a second angular movement. Such second
movement turns the fingers sufficiently to produce the angular
displacement shown in FIG. 42. According to a preferred aspect of
this invention, such movement of the finger assemblies between the
engaged and disengaged positions takes place when spin head
assembly 814 has been moved 1800 from its FIG. 36 disposition into
a face-up condition.
[0259] The engagement bits 862 can be provided with a purge gas
passage therethrough. Gas is supplied via tube 893 and is passed
through the finger assemblies.
[0260] Engaged and Disengaged Positions
[0261] FIG. 42 is a view of a portion of a finger assembly, taken
along line 7-7 in FIG. 39. Such shows in more detail the
above-described engaged and disengaged positions and movement
therebetween relative to a workpiece W. In the disengaged position,
finger 848 is positioned adjacent the semiconductor workpiece and
the finger tip and electrode contact do not overlap with workpiece
W. In the engaged position, the finger tip overlaps with the
workpiece and the electrode is brought to bear against the
workpiece. From the disengaged position, finger assembly 824, upon
the preferred actuation, is moved in a first direction away from
the disengaged position. Preferably, such first direction is
longitudinal and along first movement path axis 864. Such
longitudinal movement is linear and in the direction of arrow A as
shown in FIGS. 39 and 40. The movement moves the finger assembly to
the position shown in dashed lines in FIG. 39. Such movement is
effectuated by pneumatic operator 825 which operates upon actuation
ring 863 (FIG. 37). This in turn, causes finger actuator 862 to
engage with finger assembly 824. Such linear movement is limited by
angled slot 832a. Thereafter, the finger assembly is preferably
moved in a second direction which is different from the first
direction and preferably rotational about the first movement path
axis 864. Such is illustrated in FIG. 42 where the second direction
defines a generally arcuate path between the engaged and disengaged
positions. Such rotational movement is effectuated by secondary
linkage 865 which pneumatically engages the finger actuator to
effect rotation thereof. As so moved, the finger assembly swings
into a ready position in which a semiconductor workpiece is ready
to be engaged and held for processing. Once the finger assembly is
moved or swung into place overlapping a workpiece, the preferred
finger actuator is spring biased and released to bear against the
workpiece. An engaged workpiece is shown in FIG. 41 after the
workpiece has been engaged by finger tip 854 against a workpiece
standoff 865, and spin head assembly 814 has been rotated back into
the position shown in FIG.36. Such preferred pneumatically assisted
engagement takes place preferably along movement path axis 864 and
in a direction which is into the plane of the page upon which FIG.
42 appears.
[0262] As shown in FIG. 39, finger 848 extends away from collet 840
and preferably includes a bend 866 between collet 840 and finger
tip 854. The preferred bend is a reverse bend of around 180.degree.
which serves to point finger tip 854 toward workpiece W when the
finger assembly is moved toward or into the engaged position (FIG.
42). Advantageously, the collet 840 and hence finger 848 are
longitudinally reciprocally movable into and out of the engaged
position.
[0263] Finger Assembly Seal
[0264] The finger assembly preferably includes a finger assembly
seal 868 which is effectuated between finger 848 and a desired
workpiece when the finger assembly is moved into the engaged
position. Preferably, adjacent finger tip 854. Seal 868 is mounted
adjacent electrode contact 858 and effectively seals the electrode
contact therewithin when finger assembly 824 is moved to engage a
workpiece. The seal can be made of a suitable flexible, preferably
elastomeric material, such as VITON.
[0265] More specifically, and referring to FIG. 43, seal 868 can
include a rim portion 870 which engages workpiece surface W and
forms a sealing contact therebetween when the finger assembly is
moved to the engaged position. Such seal advantageously isolates
finger electrode 860 from the processing environment and materials
which may plate out or otherwise be encountered therein. Seal 868
can be provided with an optional bellows wall structure 894 (FIG.
43), that allows more axial flexibility of the seal.
[0266] FIG. 43 shows, in solid lines, seal 868 in a disengaged
position in which rim portion 870 is not engaged with workpiece W.
FIG. 43 also shows, in phantom lines, an engaged position in which
rim portion 870 is engaged with and forms a seal relative to
workpiece W. Preferably and advantageously, electrode contact 858
is maintained in a generally retracted position within seal 868
when the finger assembly is in the disengaged position. However,
when the finger assembly is moved into the engaged position, seal
868 and rim portion 870 thereof splay outwardly or otherwise
yieldably deform to effectively enable the electrode and hence
electrode contact 858 to move into the engaged position against the
workpiece. One factor which assists in forming the preferred seal
between the rim portion and the workpiece is the force which is
developed by spring 842 which advantageously urges collet 840 and
hence finger 860 and finger tip 858 in the direction of and against
the captured workpiece. Such developed force assists in maintaining
the integrity of the seal which is developed in the engaged
position. Another factor which assists in forming the preferred
seal is the yieldability or deformability of the finger tip when it
is brought into contact with the workpiece. Such factors
effectively create a continuous seal about the periphery of
electrode contact 858 thereby protecting it from any materials,
such as the preferred plating materials which are used during
electroplate processing.
[0267] Methods and Operation
[0268] In accordance with a preferred processing aspect of the
present invention, and in connection with the above-described
semiconductor workpiece holder, a sheathed electrode, such as
electrode 856, is positioned against a semiconductor workpiece
surface in a manner which permits the electrode to impart a voltage
bias and current flow to the workpiece to effectuate preferred
electroplating processing of the workpiece. Such positioning not
only allows a desired electrical bias to be imparted to a held
workpiece, but also allows the workpiece itself to be mechanically
held or fixed relative to the workpiece holder. That is, finger
assembly 824 provides an electrical/mechanical connection between a
workpiece and the workpiece holder as is discussed in more detail
below.
[0269] Sheathed electrode 856 includes a sheathed electrode tip or
electrode contact 858 which engages the workpiece surface. A seal
is thus formed about the periphery of the electrode tip or contact
858 so that a desired electrical bias may be imparted to the
workpiece to enable plating material to be plated thereon.
According to a preferred aspect of the processing method, the
sheathed electrode is moved in a first direction, preferably
longitudinally along a movement axis, away from a disengaged
position in which the workpiece surface is not engaged by the
sheathed electrode tip or contact 858. Subsequently, the sheathed
electrode is rotated about the same movement axis and toward an
engaged position in which the electrode tip may engage, so as to
fix, and thereafter bias the workpiece surface. Such preferred
movement is effectuated by pneumatic linkage 825 and pneumatic
operator 871 as described above.
[0270] According to a preferred aspect of the invention, the seal
which is effectuated between the sheath tip and the workpiece is
formed by utilizing a yieldable, deformable sheath tip or terminal
end 868 which includes a sheath tip rim portion 870. The sheath tip
rim portion 870 advantageously splays outwardly upon contacting the
workpiece surface to form a continuous seal about the periphery of
the electrode tip as shown in FIG. 8. The preferred electrode tip
is brought into engagement with the workpiece surface by advancing
the electrode tip from a retracted position within the sheath tip
to an unretracted position in which the workpiece surface is
engaged thereby. Such movement of the electrode tip between the
retracted and unretracted positions is advantageously accommodated
by the yieldable features of the sheath tip or terminal end
868.
[0271] In addition to providing the preferred electrical contact
between the workpiece and the electrode tip, the finger assembly
also forms a mechanical contact or connection between the assembly
and the workpiece which effectively fixes the workpiece relative to
the workpiece holder. Such is advantageous because one aspect of
the preferred processing method includes rotating the workpiece
about rotor axis 822 while the workpiece is exposed to the
preferred plating material. Such not only ensures that the
electrical connection and hence the electrical bias relative to the
workpiece is maintained during processing, but that the mechanical
fixation of the workpiece on the workpiece holder is maintained as
well.
[0272] The above described pneumatically effectuated movement of
the preferred finger assemblies between the engaged and disengaged
positions is but one manner of effectuating such movement. Other
manners of effectuating such movement are possible.
[0273] Methods Re Presenting Workpiece
[0274] The invention also includes novel methods for presenting a
workpiece to a semiconductor process. In such methods, a workpiece
is first secured to a workpiece holder. The methods work equally
well for workpiece holders known in the art and for the novel
workpiece holders disclosed herein.
[0275] In the next step in the sequence, the workpiece holder is
rotated about a horizontal axis from an initial or first position
where the workpiece holder was provided with the workpiece to a
second position. The second position will be at an angle to the
horizontal. The angle of the workpiece holder to the horizontal is
defined by the angle between the plane of the workpiece and the
horizontal. In the method, the workpiece holder is advantageously
suspended about a second horizontal axis which is parallel to the
first horizontal axis of the workpiece holder. At this point in the
method, the angle between the first and second horizontal axes and
a horizontal plane corresponds to the angle between the workpiece
holder and the horizontal. The workpiece holder is then pivoted
about the second horizontal axis to move the workpiece and the
workpiece holder from its initial location to a final location in a
horizontal plane. Advantageously, when the workpiece holder is
pivoted about the second horizontal axis, the first horizontal axis
also pivots about the second horizontal axis.
[0276] Preferably, during the step of rotating the workpiece holder
about the first horizontal axis, the angle of the workpiece holder
with respect to some known point, which is fixed with respect to
the workpiece holder during the rotation process, is continually
monitored. Monitoring allows for precise positioning of the
workpiece holder with respect to the horizontal surface.
[0277] Likewise, during pivoting of the workpiece holder about the
second horizontal axis, it is preferable that the angle defined by
the line connecting the first and second horizontal axes and the
horizontal plane be continually monitored. In this manner, the
absolute position of the workpiece holder (and hence the workpiece
itself) will be known with respect to the horizontal plane. This is
important since the horizontal plane typically will contain the
process to which the workpiece will be exposed.
[0278] It should be noted that in the above and following
description, while the workpiece is described as being presented to
a horizontal plane, it is possible that the workpiece may also be
presented to a vertical plane or a plane at any angle between the
vertical and the horizontal. Typically, the processing plane will
be a horizontal plane due to the desire to avoid gravitational
effects on process fluids to which the workpiece is exposed. In one
embodiment after the workpiece has been presented to the processing
plane, the workpiece holder is rotated about a spin axis to cause
the workpiece to spin in the horizontal plane. Although not
required in all semiconductor manufacturing processes, this is a
common step which may be added in the appropriate circumstance.
[0279] The next advantageous step in the method consists of
pivoting the workpiece holder about the second horizontal axis back
along the path that the workpiece holder was initially pivoted
along when presenting the workpiece to the horizontal process
plane. There is no requirement that the workpiece holder be pivoted
back to the same position whence it began, although doing so may
have certain advantages as more fully described below.
[0280] The method advantageously further consists of the step of
rotating the workpiece holder about the first horizontal axis to
return the workpiece to the position when it was initially
presented to and engaged by the workpiece holder. It is
advantageous to rotate the workpiece holder about the first axis in
a direction opposite from the initial rotation of the workpiece
holder.
[0281] The advantage of having the workpiece holder terminate at an
end position which corresponds to the initial position when the
workpiece was loaded into the workpiece holder is efficiency. That
is, additional machine movements are not required to position the
workpiece holder to receive a new workpiece.
[0282] The method more preferably includes the step of rotating the
workpiece holder about the first horizontal axis at at least two
support points along the first horizontal axis. This beneficially
provides support and stability to the workpiece holder during the
rotation process and subsequent movement of the apparatus.
[0283] The method also more preferably includes the step of
pivoting the workpiece holder along with the first horizontal axis
about the second horizontal axis at at least two support points
along the second horizontal axis. This beneficially provides
additional support for the workpiece holder while allowing the
workpiece holder to be moved in a vertical or "Z-axis"
direction.
[0284] Importantly, the only motion described in the above method
is rotational motion about several axes. In the method described,
there is no translational motion of the workpiece holder in a X-,
Y-, or Z-axis without corresponding movement in another axis as a
result of rotating through an arc.
[0285] Electroplating Processing Station
[0286] The workpiece process tool may comprise several different
modules for performing a variety of manufacturing process steps on
the workpiece or semiconductor wafer. The workpiece processing tool
may advantageously contain electroplating module 20, alternately
known more generally as a workpiece processing station.
[0287] The plating module 20 of FIG. 44 is shown as a 5 bay plating
module. This allows for up to 5 workpieces to be processed
simultaneously. Each of the 5 electroplating bays may alternately
be known as a workpiece processing station. Each workpiece
processing station is advantageously provided with a workpiece
support 401. Each workpiece support is further advantageously
provided with a processing head 406, an operator arm 407, and an
operator base 405. The details of the workpiece support 401 are
described below. The operator base 405 of the workpiece support 401
is mounted to the workpiece processing station by securing it to
the chassis or shelf of the workpiece module.
[0288] Workpiece support 601 is shown in a "open" or "receive
wafer" position whereby a robotic arm or other means will provide a
workpiece to the workpiece support. The workpiece support will
positively engage the workpiece (described more fully below) by
fingers 409 (or more precisely, by finger tips of finger
assemblies, which are also described more fully below). The
processing head 406 will then rotate about the operator arm 407 to
place the workpiece in an essentially downward facing position.
Operator arm 407 will then pivot about operator base 405 to place
the workpiece in the processing bowl as shown at 602 of FIG. 2. The
manufacturing step or process will then be performed upon the
workpiece. Following the manufacturing step, the workpiece will be
returned to the open position shown by workpiece support 601 at
which time the workpiece will be removed from fingers 409.
[0289] Although the invention is described for an electroplating
process, it is to be noted that the general arrangements and
configurations of the workpiece processing stations and their
combination into a multi-workpiece processing station unit may be
applied to a variety of processes used in manufacturing.
[0290] FIG. 44 also shows an optional beam emitter 81 for emitting
a laser beam detected by robotic wafer conveyors (not shown) to
indicate position of the unit.
[0291] Turning to FIG. 45, an isometric view of the electroplating
module 20 with the front panel cut away reveals that the module is
advantageously provided with a series of process bowl assemblies or
plating chamber assemblies 603, a process fluid reservoir 604, and
an immersible pump 605. Each process bowl assembly 603 is connected
to the immersible pump 605 by fluid transfer lines which preferably
are provided with instrumentation and control features described
more fully below.
[0292] The details of the bowl assemblies and their arrangement and
configuration with the other components of the invention described
herein are described more fully below.
[0293] The process fluid reservoir 604 is mounted within the
processing module 20 by attaching it to the module frame or chassis
606. Turning to FIG. 4, the fluid reservoir 604 is shown in
isolation with process bowl assembly 603, immersible pump 605, and
pump discharge filter 607.
[0294] Turning briefly to FIG. 49, a side sectional view of the
fluid reservoir 604 is shown. As can be seen in FIG. 49, process
fluid reservoir 604 is advantageously a double-walled vessel having
an outer reservoir wall 608 and an inner reservoir wall 609
defining a reservoir safety volume 611 therebetween. Fluid
reservoir 604 is preferably a double-walled vessel in the event
that the inner wall 609 should leak. A double-walled vessel
construction design would allow the leak to be contained within the
reservoir safety volume 611 between the outer wall 608 and the
inner wall 609. Should the reservoir safety volume become filled
with fluid leaking from the inner vessel 612, the fluid would
overflow through reservoir overflow opening 610. Reservoir opening
610 is preferably provided with guttering or the like to channel
overflow fluid to a safe collection point (not shown). Further, the
reservoir safety volume may be provided with liquid detection
sensors (not shown) to alert operators in the event that the inner
wall of reservoir 604 should become breached and fluid enter the
reservoir safety volume 611.
[0295] The process module may also be provided with a heat
exchanger 613. Turning to FIG. 48, the heat exchanger 613 is shown
in front elevation view of the process fluid reservoir 604. The
heat exchanger shown in FIG. 48 is a double helix-type having an
exchanger inlet 614 and an exchanger outlet 615. The exchanger 613
may be used for either cooling or heating the process fluid by
circulating respectively either a cooler or warmer fluid through
the exchanger than is present in the reservoir. Alternate designs
of heat exchangers may also effectively be used in the apparatus of
the present invention.
[0296] Bowl Assembly
[0297] Returning to FIG. 46, a plurality of bowl assembly 603 are
shown mounted in reservoir top 618. The indicated process chamber
603 is shown in isometric detail in FIG. 47.
[0298] Turning to FIG. 47, it is seen that the bowl assembly 603 is
secured within reservoir top 618. The process bowl assembly
consists of a process bowl or plating chamber 616 having a bowl
side 617 and a bowl bottom 619. The process bowl is preferably
circular in a horizontal cross section and generally cylindrical in
shape although the process bowl may be tapered as well.
[0299] The invention further advantageously includes a cup assembly
620 which is disposed within process bowl 616. Cup assembly 620
includes a fluid cup 621 having a cup side 622 and a cup bottom
623. As with the process bowl, the fluid cup 621 is preferably
circular in horizontal cross section and cylindrical in shape,
although a tapered cup may be used with a tapered process bowl.
[0300] Process fluid is provided to the process bowl 616 through
fluid inlet line 625. Fluid inlet line rises through bowl bottom
opening 627 and through cup fluid inlet opening 624 and terminates
at inlet line end point 631. Fluid outlet openings 628 are disposed
within the fluid inlet line 625 in the region between the cup fluid
inlet opening 624 and fluid line end point 631. In this way, fluid
may flow from the fluid inlet line 625 into the cup 621 by way of
the inlet plenum 629.
[0301] The cup assembly 620 preferably includes a cup filter 630
which is disposed above the fluid inlet openings and securely fits
between the inner cup wall 622 and the fluid inlet line 625 so that
fluid must pass through the filter before entering the upper
portion of cup 621.
[0302] In an electroplating process, the cup assembly 620 is
advantageously provided with a metallic anode 634. Anode 634 is
secured within the cup assembly by attaching it to the end point
631 of the fluid inlet line. Anode 634 is thus disposed above the
cup filter 630 as well as above fluid inlet opening 628. Anode 634
is preferably circular in shape and of a smaller diameter than the
inside diameter of cup 621. Anode 634 is secured to the end point
631 of fluid inlet line 625 so as to center the anode 634 within
cup 621 creating an annular gap or space 635 between the inner cup
wall 622 and the edge of anode 634. Anode 634 should be so placed
such as to cause the anode annular opening 635 to be of a constant
width throughout its circumference.
[0303] The outer cup wall 636 is advantageously of a smaller
diameter than the inside diameter of bowl 616. Cup assembly 620 is
preferably positioned within bowl 616 such that a first annular
space or process fluid overflow space 632 is formed between bowl
side 617 and cup outer wall 636. The cup assembly is more
preferably positioned such that the annular fluid overflow space
632 is of a constant width throughout its circumference.
[0304] Cup assembly 620 is further advantageously positioned within
bowl 616 such that cup upper edge 633 is below bowl upper edge 637.
Cup 621 is preferably height-adjustable with respect to bowl upper
edge 637, as more fully described below.
[0305] Bowl bottom 619 is preferably configured so as to have a
large open area allowing the free transfer of fluid therethrough.
In the preferred embodiment, this is achieved by the structure
shown in FIG. 47 wherein the process bowl bottom 619 is composed of
crossbars 626 which intersect at bowl bottom center plate 639
creating fluid return openings 638. Bowl bottom center plate 639 is
provided with bowl bottom opening 627 to allow fluid inlet line 625
to pass therethrough. In the preferred embodiment, the bowl sides
617 below the reservoir top 618 are also similarly constructed so
that bowl sides below reservoir top 618 are essentially composed of
4 rectangular sections which then turn inward towards bowl bottom
center plate 639 intersecting thereat. Such a configuration allows
for a high degree of fluid flow to pass through the bowl lower
portion which is disposed within reservoir 604.
[0306] Thus, operation, process fluid is provided through process
fluid inlet line 625 and discharges through fluid outlet openings
628 within the lower part of the cup assembly 620. By virtue of cup
filter 620, fluid entering the fluid inlet plenum 629 is
distributed across the plenum and then flows upward through filter
630 to the bottom of anode 634.
[0307] From the top side of filter 630, the process fluid continues
to flow in an upward direction by virtue of continuing feed of
process fluid through process inlet line 625. The process fluid
flows around the annular gap 635 between the anode 634 and the
inner cup wall 622. As the process fluid continues to well up
within cup 621, it will eventually reach upper cup edge 633 and
will overflow into the overflow annular gap 632 between the outer
cup wall 636 and the inner wall of bowl 616.
[0308] The overflowing fluid will flow from the overflow gap 632
downward through the gap and back into reservoir 604 where it will
be collected for reuse, recycling, or disposal. In this manner, no
process fluid return line is required and no elaborate fluid
collection system is necessary to collect surplus fluid from the
process.
[0309] As a further advantage, the location of the cup filter 630
and anode 634 within the cup 621 provides an even distribution of
fluid inlet into the cup. The even distribution beneficially
assists in providing a quiescent fluid surface at the top of cup
621. In like manner, maintaining a constant distance between the
outer wall of cup 636 and the inner wall of bowl 616 in providing
the overflow gap 632 will assist in providing an even flow of fluid
out of cup 621 and into the reservoir 604. This further
beneficially assists in providing the desired quiescence state of
the process fluid at the top of cup 621.
[0310] The material selection for cup filter 620 will be dictated
by the process and other operating needs. Typically, the filter
will have the capability of filtering particles as small as 0.1
microns. Likewise, the choice of materials for anode 634 will be
dictated by the desired metal to be electroplated onto the
workpiece.
[0311] While the above bowl assembly has been described
particularly for an electroplating process, it can be seen that for
a process where a flow of fluid is required but no anode is
required removing the anode 634 from the cup assembly 603 will
provide a quiescent pool of liquid for the process. In such an
arrangement, the end point 631 of the fluid inlet line 625 would be
capped or plugged by a cap or plug rather than by the anode
634.
[0312] To assist in ensuring that process fluid overflows into the
annular gap 632 evenly, it is necessary to ensure that the cup
upper edge 633 is level such that fluid does not flow off of one
side of cup 621 faster than on another side. To accomplish this
objective, levelers are preferably provided with the process bowl
assembly 603.
[0313] Turning now to FIG. 50, the process bowl assembly of FIG. 47
is shown in cross section along with the workpiece support 401. The
process bowl assembly 603 is shown mounted to the process module
deck plate 666. Plating chamber assembly 603 is preferably provided
with levelers 640 (only one of which is shown in this view) which
allow the plating chamber assembly to be leveled relative to the
top of reservoir 618. The levelers may consist of jack screws
threaded within the edge of module deck plate 666 and in contact
with the process module frame 606 so as to elevate the process bowl
assembly 603 relative to the process module 20. The process bowl
assembly 603 is preferably provided with three such bowl levelers
distributed about the bowl periphery. This allows for leveling in
both an X and Y axis or what may be generically described as "left
and right leveling and front and rear leveling."
[0314] Since process bowl assembly 603 is free to move with respect
to fluid reservoir 604, when process bowl assembly 603 is fit
closely within fluid reservoir 604 as shown in FIG. 50, the process
bowl/fluid reservoir junction preferably has a compliant bowl seal
665 disposed therebetween to allow movement of the process bowl 616
with respect to reservoir inner wall 609. Compliant seal 665
further prevents process fluid from passing through the opening
between the process bowl and the reservoir wall.
[0315] Cup assembly 620 is preferably provided with cup height
adjuster 641. The cup height adjuster shown and described herein
consists of a cup height adjustment jack 643 which is positioned
about an externally portion of inlet line 625. Cup 621 is secured
to cup height adjustment jack 643 with cup lock nut 642. Cup lock
nut 642 is used to secure cup 621 in its height position following
adjustment. The upper end of cup height adjustment jack 641 is
provided with adjustment tool access holes 667 to allow for
adjusting of the height of the cup from the top of the bowl rather
than the underside. The cup height adjuster 641 may additionally be
provided with a fluid seal such as an o-ring (not shown) disposed
within the annular space formed between the adjsutment jack 643 and
the cup bottom 623.
[0316] The process bowl assembly 603 is more preferably provided
with an additional height adjuster for the anode 634. Since it is
desirable to be able to adjust the distance between the anode 634
and the workpiece based upon the particular electroplating process
being used, anode height adjuster 646 is beneficially provided.
Anode height adjuster 646 is formed by mounting the anode 634 on
the threaded anode post 664. A threaded anode adjustment sleeve 663
is used to connect the threaded upper end of inlet line 625. Anode
adjustment sleeve 663 is provided with sleeve openings 668 to allow
fluid to pass from fluid outlet openings 628 into the inlet plenum
629. The space between the bottom of anode post 664 and the upper
end of fluid inlet line 625, and bounded by the anode adjustment
sleeve 663, defines a fluid outlet chamber 662. Fluid outlet
chamber is of variable volume as the anode post 664 moves upward
and downward with height adjustment of the anode 634.
[0317] On the bowl leveler 640 and the height adjusters 641 and 646
described above, it is additionally desirable to provide them with
locking mechanisms so that once the desired positioning of the
device (i.e., the bowl, the cup, or the anode) is achieved, the
position may be maintained by securing the adjusters so that they
do not move out of adjustment as a result of vibration or other
physical events.
[0318] Allowing independent height adjustment of the cup and anode
each with respect to the bowl provides a large degree of
flexability in adjusting the process bowl assembly 603 to
accomodate a wide selection of processes.
[0319] Fluid Transfer Equipment
[0320] To provide process fluid to the process bowl assembly in the
electroplating module of the present invention, the module is
advantageously provided with fluid transfer equipment. The fluid
transfer equipment is provided to draw process fluid from a
reservoir, supply it to the process bowl assemblies, and return it
to a common collection point.
[0321] Turning now to FIG. 48, a cross section of the reservoir and
process bowl assemblies and additional equipment shown in FIG. 46
is shown. FIG. 48 shows a immersible pump 605 which is mounted to
the reservoir top 618. The plating module is advantageously
provided with such a pump which further consists of a fluid suction
or pump suction 647 which draws process fluid from the reservoir
604. The immersible pump pumps fluid from the pump suction 640 into
the pump body 653 and out through the fluid discharge or pump
discharge 648. Immersible pump 605 is preferably driven by an
electric pump motor 650.
[0322] In alternate embodiments of the present invention, a
submersible pump may be deployed. However, the immersible pump has
the advantage that it may be easily removed for servicing and the
like. In yet another embodiment, individual pumps for each of the
process bowl assemblies may be deployed or, process bowls
assemblies may share a set of common pumps. Each such pump would
have a process fluid inlet suction and a process fluid
discharge.
[0323] Returning to the preferred embodiment of FIG. 48, the
plating module preferably has a pump discharge filter 607 which is
connected in line with pump discharge 648. Pump discharge filter
607 is preferably provided with a removable filter top 649 so that
filter cartridges within the filter may be replaced. The filter
type, size and screen size will be dictated by the needs of the
particular process being deployed at the time.
[0324] From the pump discharge filter 607, the process fluid exits
through filter outlet 651 and into supply manifold 652. The supply
manifold supplies all of the process bowl assemblies 603 with
process fluid. Branching off from the supply manifold 652 are the
individual fluid inlet lines 625. The fluid inlet lines 625 are
preferably provided with flow control devices which are more fully
described below.
[0325] At the down stream end of the supply manifold 652 after the
final processing bowl assembly 661, the manifold is routed to fluid
return line 654. Although the supply manifold could be terminated
at an open ended point at optional end point 655, in the preferred
embodiment, the supply manifold 652 is additionally provided with a
back pressure regulator 656, which is described more fully below.
Since it is advantageous to have the back pressure regulator
outside of the fluid reservoir for ease of access, the fluid return
line 654 is provided when the back pressure regulator 656 is
employed.
[0326] Control Devices
[0327] In the preferred embodiment, the work station processing
module of the present invention further includes devices for
controlling the flow and distribution of the process fluid to the
process bowl assemblies.
[0328] With reference to FIG. 48, the apparatus of the present
invention is beneficially provided with flow sensors 657 which are
disposed within the fluid inlet line 625 for each individual
process bowl assembly 603. The flow sensors 657 will measure the
amount of process fluid flowing through each fluid inlet line and
will generate a signal which will be transmitted by flow signal
line 659. A signal will typically be an electrical signal but may
also be a pneumatic or other type of signal.
[0329] The processing modules 603 are also preferrably provided
with flow restrictors 658 which are disposed in fluid inlet lines
625 after the flow sensor 657 but before the fluid outlet opening
628 within cup 621 (shown in FIG. 47). The flow restrictor may
alternately be known as a variable orifice or a control valve. The
flow restrictor 658 may either be manually adjustable, or may be
responsive to a signal provided by flow control signal line 660.
The flow control signal line may be a pneumatic, electrical or
other type of signal. The objective of the flow controller is to
control the quantity of process fluid being provided to the fluid
cup 621 during the processing step of manufacturing the
semiconductor. When the flow restrictor is responsive to a control
signal, the information provided from the flow signal line 659 may
be used to modify or generate the flow control signal which is then
provided to the flow controller 658. This control may be provided
by a micro processor or by other control devices which are
commercially available.
[0330] More preferably, the semiconductor processing module is
provided with back pressure regulator 656. As pump discharge filter
607 becomes restricted due to captured filtrate, the pressure
within supply manifold 652 will drop, reducing flow of process
fluid to the fluid cups 621. Back pressure regulator 656 is used to
maintain a preselected pressure in the supply manifold 652 to
ensure that sufficient pressure is available to provide the
required flow of process fluid to the fluid cups. Back pressure
regulator 656 further comprises an internal pressure sensor and
preferably includes a signal generator for generating a control
signal to open or close the back pressure regulator to increase or
decrease the pressure in the supply manifold. The back pressure
regulator may be controlled by an external controller such as a
micro processor or it may have a local set point and be controlled
by an internal local control mechanism.
[0331] In an alternate embodiment, where a dedicated process pump
is used for each process bowl assembly, a back pressure regulator
would typically not be required.
[0332] Plating Methods
[0333] The present invention also includes a novel method for
processing a semiconductor workpiece during manufacturing.
[0334] In the preferred embodiments of the method, a semiconductor
workpiece or wafer is presented to the semiconductor manufacturing
process. This may be accomplished by use of the workpiece support
401 shown in FIG. 50 and described more fully herein. FIG. 51 shows
the workpiece W being presented to the process. At the time that
the workpiece is presented to the process, the process fluid, which
in an electroplating process is an electrolytic solution, is cause
to flow within a processing chamber (herein the cup 621) to the
workpiece. This assures that a sufficient quantity of fluid is
available for the required process step.
[0335] The workpiece W is preferably presented to the process in a
precisely located position so that all surfaces of the workpiece
are exposed to the solution. In an electroplating process, it is
advantageous to expose only the downward facing or working surface
of the wafer to the electrolytic solution and not the backside of
the wafer. This requires accurate positioning of the wafer with
respect to the fluid surface. In an electroplating process, the
method also requires the step of accurately positioning the
workpiece with respect to the anode 634 so that the anode and
workpiece are separated by an equal distance at all points.
[0336] Once the workpiece has been positioned as the process may
specifically require, the next step in the method is performing the
actual processing step itself. For example, in an electroplating
application, the processing step would include applying an electric
current to the workpiece so as to generate the current through the
electrolytic solution thereby plating out a layer of a desired
metallic substance on the wafer. Typically a current will be
applied to the anode as well, with a negative current being applied
to the workpiece. The processing step is applied for the length of
time which is dictated by the process itself.
[0337] The process further includes the step of continuing a flow
of the process fluid such that the process fluid overflows the
processing chamber and falls under gravitational forces into a
process fluid reservoir. Preferrably the process fluid reservoir is
the same reservoir which provides the process fluid or solution to
the process.
[0338] As an additional step in the method of processing the
semiconductor wafer in the electroplating process, the method
includes the further step of spinning or rotating the workpiece
about a vertical axis while it is exposed to the electrolytic
solution. The rate of rotation varies between about 5 and 30 rpm
and is more preferably approximately 10 rpm. The rotation step
provides the beneficial result of additional assurance of even
distribution of the electrolytic solution across the face of the
workpiece during the electroplating process.
[0339] After the processing has been performed on the semiconductor
wafer, the method advantageously includes the step of removing the
workpiece from the process and returning it to a position where it
may be removed for further processing or removal from the
semiconductor workpiece process tool.
[0340] The method preferably includes the step of performing the
above-described steps at a series of process bowls having a common
fluid reservoir such that the overflowing fluid gravity drains into
a common fluid reservoir.
[0341] In compliance with the statute, the invention has been
described in language more or less specific as to structural and
methodical features. It is to be understood, however, that the
invention is not limited to the specific features shown and
described, since the means herein disclosed comprise preferred
forms of putting the invention into effect. The invention is,
therefore, claimed in any of its forms or modifications within the
proper scope of the appended claims appropriately interpreted in
accordance with the doctrine of equivalents.
* * * * *