U.S. patent application number 09/811379 was filed with the patent office on 2001-09-13 for reactor vessel having improved cup, anode and conductor assembly.
Invention is credited to Hanson, Kyle M., Woodruff, Daniel J..
Application Number | 20010020583 09/811379 |
Document ID | / |
Family ID | 22343164 |
Filed Date | 2001-09-13 |
United States Patent
Application |
20010020583 |
Kind Code |
A1 |
Woodruff, Daniel J. ; et
al. |
September 13, 2001 |
Reactor vessel having improved cup, anode and conductor
assembly
Abstract
An improved anode, cup and conductor assembly for a reactor
vessel includes an anode assembly supported within a cup which
holds a supply of process fluid. The cup is supported around its
perimeter within the reactor vessel. The anode assembly has an
anode shield carrying an anode, the anode shield having upwardly
extending brackets with radially extending members. A diffusion
plate is supported above the anode by the anode brackets using
first bayonet connections. The anode shield and the anode are
supported from below by a delivery tube which also serves to
deliver process fluid to the cup. A second bayonet connection is
provided between a top portion of the delivery tube and the anode
assembly. The fluid delivery tube has a fixed height within the
vessel. The anode elevation is adjusted by the interposing of a
spacer of desired thickness between the anode and the tube. An
electrical conductor is connected to the anode, and passes through
the tube to be electrically accessible outside the vessel. The
conductor is connected to the anode with a plug-in connection which
is completed when the tube is coupled to the anode by the second
bayonet connection. A spring loaded bellows seal and a corrugated
sleeve seal the electrical conductor from the anode, through the
delivery tube, and to the outside electrical accessibility. The
diffusion plate and the anode assembly are installable and
removable from a top side of the reactor vessel using a tool which
is lockable to the diffusion plate or to the anode. The tool
provides a handle for manual engagement or disengagement of the
first and second bayonet connections.
Inventors: |
Woodruff, Daniel J.;
(Kalispell, MT) ; Hanson, Kyle M.; (Kalispell,
MT) |
Correspondence
Address: |
PERKINS COIE LLP
PATENT-SEA
P.O. BOX 1247
SEATTLE
WA
98111-1247
US
|
Family ID: |
22343164 |
Appl. No.: |
09/811379 |
Filed: |
March 15, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09811379 |
Mar 15, 2001 |
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09112300 |
Jul 9, 1998 |
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6228232 |
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Current U.S.
Class: |
204/242 |
Current CPC
Class: |
C25D 17/001 20130101;
C25D 5/08 20130101; C25D 17/06 20130101; C25D 7/123 20130101 |
Class at
Publication: |
204/242 |
International
Class: |
C25D 017/00 |
Claims
1. In a reactor vessel for processing a semiconductor wafer, the
vessel having a cup for holding a level of processing fluid, an
anode arranged at a first position within the cup, and a wafer
support for holding a wafer at a second position spaced from the
anode, the improvement comprising: an anode; an anode support
supporting said anode at an elevation within the cup, said anode
and said anode support having interengaging members forming a
bayonet connection therebetween.
2. The improvement according to claim 1, wherein said anode support
extends vertically from a base plate of said vessel, through a
bottom wall of said cup to said anode.
3. The improvement according to claim 1, wherein said anode support
comprises a tube having a fluid inlet connectable to an external
source of process fluid, and a fluid outlet in fluid communication
with said cup, and a fluid path between said fluid inlet and said
fluid outlet.
4. The improvement according to claim 1, comprising an anode shield
fastened to said anode, and at least partially defining a plurality
of slots, and said anode support includes a plurality of radially
extending tabs adapted to engage said slots when said anode is
rotated on said anode support, said slots and said tabs defining
said bayonet connection.
5. The improvement according to claim 4, further comprising an
electrical conductor extending through said anode support and
electrically connected to said anode by a plug-and-socket
connection, and a bellows seal surrounding said plug-and-socket
connection and pressed to said anode by engagement of the bayonet
connection.
6. The improvement according to claim 1, wherein one of said anode
or said anode support includes slots, and the respective other
includes corresponding radial tabs which together define said
bayonet connection, said slots each including a vertical slot
region which intersects a horizontal slot region, said horizontal
slot region having a recess for receiving a tab therein: and a
spring arranged between said anode and said support for holding
said tabs into said recesses.
7. The improvement according to claim 1 wherein said anode support
comprises a tube having an attachment plate fastened thereto
between said anode and said tube, said attachment having radially
extending tabs, and said anode having slots for receiving said tabs
when said anode is rotated relative to said tube.
8. In a reactor for processing a semiconductor wafer, the vessel
having a cup for holding a level of process fluid, an anode
arranged at a position within the cup, and a wafer support for
holding a wafer at a second position spaced from the anode, the
improvement comprising: an anode diffusion plate; and an anode
diffusion plate support, said anode diffusion plate arranged
between the anode and the wafer, the anode diffusion plate support
and the anode diffusion plate having interengaging parts which form
at least one bayonet connection therebetween.
9. The improvement according to claim 8, wherein said diffusion
plate support includes a plurality of brackets and said diffusion
plate includes a plurality of slots adapted to be engaged by said
brackets by rotation of said diffusion plate relative to said
diffusion plate support.
10. The improvement according to claim 9 wherein said brackets each
include an upstanding leg and a radially extending end portion, and
said diffusion plate includes a circumferentially arranged channel
sized for receiving said end portion therein, and a plurality of
recesses for passing said end portions into said channel.
11. The improvement according to claim 8, wherein said diffusion
plate support comprises an anode shield which carries said anode,
and said brackets extend around and above said anode to said
diffusion plate.
12. A reactor for electroplating a wafer, comprising: a vessel; a
cup for holding a supply of process fluid, said cup held within
said vessel; an anode located within said cup and having a top
surface and a bottom surface; a conductor electrically connected to
said bottom surface of said anode by a plug-in connection; an anode
support mechanically connected to said anode by a bayonet
connection; and said conductor extending downwardly through said
vessel and exposed outside of said housing for electrical
connection thereto.
13. The reactor according to claim 12, further comprising a
diffusion plate and an anode shield, said anode shield arranged
against said bottom surface of said anode and having brackets
extending above said top surface of said anode, and said diffusion
plate carried on said brackets, spaced at a distance above said top
surface of said anode.
14. The reactor according to claim 13 wherein said diffusion plate
and said brackets include interengaging parts which form at least
one bayonet connection.
15. A reactor according to claim 13, wherein said brackets are
formed in unitary fashion with said anode shield, and extend
perpendicularly therefrom, and each of said brackets has a tab
member, and said diffusion plate includes a plurality of horizontal
slots, and each tab member is received in one of said bayonet
slots.
16. A reactor according to claim 12, wherein said anode support
comprises an anode post surrounding said conductor, said cup having
an opening in a bottom wall thereof for receiving the anode post,
said anode post having a fluid inlet which is connectable outside
said vessel, and a fluid outlet which is exposed within said cup,
and a fluid path between said inlet and said outlet.
17. A reactor according to claim 12, wherein said anode support
comprises a tube, and said mechanical connection includes radially
extending tabs carried by said tube which engage horizontal slots
carried by said anode.
18. The reactor according to claim 12 further comprising a tool
having a handle, said tool and said diffusion plate having
interengaging portions which together define a bayonet connection,
said tool and said diffusion plate lockable together by vertical
mating and then relative rotation.
19. The reactor according to claim 18 further comprising a tool
having a handle, said tool and said anode carrying interengaging
portions which together define a bayonet connection, said tool and
said anode lockable together by vertical mating and then relative
rotation.
20. The reactor according to claim 12 further comprising a tool
having a handle, said tool and said anode carrying interengaging
portions which together define a bayonet connection, said tool and
said anode lockable together by vertical mating and then relative
rotation.
21. A reactor for electroplating a wafer, comprising: a vessel; a
cup for holding a supply of process fluid, said cup held within
said vessel; an anode located within said cup and having a top
surface and a bottom surface; an anode support extending from said
vessel and supporting said anode, said anode support and said anode
having interengaging parts which together comprise a bayonet
connection; an electrical conductor electrically connected to said
anode and electrically connected to an electrical power source
outside of said vessel; anode brackets carried by said anode and
extending to a position above said anode; and a diffusion plate
supported on said anode brackets.
22. The reactor according to claim 21, wherein said brackets are
formed as a unitary structure with an anode shield arranged beneath
said anode, and said brackets include tab members which are
received in horizontal slots formed in edge regions of said
diffusion plate.
23. A method of assembling a reactor vessel having a reservoir
container with an open top and a cup supported within the container
and accessible through the open top, and an anode support
accessible through the open top, comprising the steps of: providing
an anode; providing that said anode and said anode support include
therebetween engageable parts which define a bayonet connection;
lowering said anode through the open top and engaging said parts in
a vertical direction; and turning said anode with respect to said
anode support to fully engage said parts.
24. The method according to claim 23 comprising the further steps
of: providing a tool which engages and holds said anode and which
includes a handle; engaging said tool to said anode and holding
said anode with said tool; and said steps of lowering and turning
said anode are undertaken by force exerted on said anode by said
tool; and disengaging said tool from said anode.
25. The method according to claim 24 wherein said step of engaging
said tool to said anode is further defined in that said tool and
said anode include therebetween interacting portions which together
define a bayonet connection, and said tool is engaged to said anode
by vertical mating and then relative rotation.
26. The method according to claim 23 comprising the further steps
of: providing a diffusion plate support extending above said anode;
providing that said diffusion plate and said diffusion plate
support have engageable portions which together define a bayonet
connection; lowering said diffusion plate through said open top to
engage said portions in a vertical direction; and turning said
diffusion plate with respect to said diffusion plate support to
fully engage said portions.
27. The method according to claim 26 comprising the further steps
of: providing a tool which engages and holds said diffusion plate
and which includes a handle; engaging said tool to said diffusion
plate and holding said diffusion plate with said tool; and said
steps of lowering and turning said diffusion plate are undertaken
by force exerted on said diffusion plate by said tool: and
disengaging said tool from said diffusion plate.
28. The method according to claim 27 wherein said step of engaging
said tool to said diffusion plate is further defined in that said
tool and said diffusion plate include between them interacting
portions which together define a bayonet connection, and said tool
is engaged to said diffusion plate by vertical mating and then
relative rotation.
29. A reactor vessel for electroplating a semiconductor wafer,
comprising: a reservoir container including a base plate and a
surrounding container sidewall upstanding from said base plate; a
cup arranges above said base plate, said cup having a bottom wall
and a surrounding cup sidewall upstanding from said bottom wall,
said cup sidewall defining a level of process fluid held within
said cup; an electrode plate arranged within said cup below said
level; a tube sealed to said base plate and extending through said
cup bottom wall to support said electrode plate from said base
plate, said tube having a substantially closed bottom, and a top;
and a conductor wire, arranged within said tube and passing through
said tube bottom and top, said conductor wire having a plug
electrically connected to said electrode plate.
30. The reactor vessel according to claim 29, wherein said tube
includes an inlet opening for receiving process fluid, and at least
one outlet opening into said cup.
31. The reactor vessel according to claim 29, including a sleeve
surrounding said conductor wire and sealed to said electrode plate
and to said bottom of said tube.
32. The reactor vessel according to claim 31, including a bellows
seal surrounding said plug, said top of said tube mechanically
connectable to said electrode plate, said electrode plate having a
socket for receiving said plug to make electrical connection
thereto, and said bellows seal partially compressed to seal against
said electrode plate when said plug is received into said
socket.
33. The reactor vessel according to claim 29, further comprising a
spacer adapted to be interposed between said electrode plate and
said top of said tube to adjust the elevation of said electrode
plate.
34. The reactor vessel according to claim 33, wherein said spacer
is substantially C-shaped.
35. The reactor vessel according to claim 29, further comprising a
plate structure connected to said top of said tube and including a
plurality of radially extending tabs, and said electrode plate
includes a plurality of slot regions for receiving said tabs, said
slot regions having substantially horizontal portions to receive
said tabs by relative rotation between said electrode plate and
said plate structure.
36. The reactor vessel according to claim 35, wherein said
electrode plate includes an anode disc and an anode shield
underlying said anode disc, and said slot regions are formed
between said anode disc and said anode shield.
37. The reactor vessel according to claim 29, further comprising a
sleeve surrounding said conductor wire, and a tube fitting and a
tube coupling at each end of said sleeve, said tube fittings fixed
to said tube bottom and top respectively, said sleeve connected to
said fittings and sealed thereto by said tube couplings.
38. The reactor vessel according to claim 37, wherein said
conductor wire and said sleeve each include an excess length
between said fittings.
39. The reactor vessel according to claim 37, wherein said sleeve
comprises a corrugated tube portion.
40. The reactor vessel according to claim 29, wherein said cup is
supported around its perimeter on said surrounding container
sidewall.
41. The reactor vessel according to claim 40, wherein said cup
further comprises an outer wall surrounding said cup sidewall and
fixed thereto, with intermittent gaps therebetween for the vertical
passage of fluid, said outer wall having a first radial surface
facing downwardly; and said reservoir container further includes an
exhaust ring supported on said vessel sidewall and having a second
radial surface facing upwardly for supporting said first radial
surface; said exhaust ring spaced from said outer wall to define an
exhaust plenum therebetween, said outer wall having at least one
inlet opening into said exhaust plenum and said exhaust ring having
at least one outlet opening out of said plenum.
42. The reactor vessel according to claim 29, wherein said cup
includes a first horizontal surface around its perimeter facing
downwardly and said reservoir container includes a second
horizontal surface facing upwardly for abutting said first
horizontal surface and supporting said cup on said reservoir
container.
43. The reactor vessel according to claim 29, wherein said tube is
sealed to said cup bottom wall.
44. In an electroplating reactor vessel for use with a wafer
holding assembly which holds a wafer to be electroplated as
electrical cathode, the wafer spaced from an anode arranged within
a cup within the reactor vessel, and which cup holds a level of
process fluid, the improvement comprising: a structure for
supporting the cup within the reactor vessel, said structure
carried by a sidewall of the reactor vessel, supporting the cup
substantially around a perimeter of the cup.
45. The improvement according to claim 44, further comprising a
tube fixed within said vessel and supporting the anode from a base
of said vessel, and a spacer between said anode and said tube for
adjusting the height of said anode.
46. The improvement according to claim 45, wherein said tube
includes a process fluid inlet external to said vessel, an internal
fluid pathway, and a fluid outlet into said cup.
47. The improvement according to claim 46, further comprising an
electrical wire connected to said anode and passing through said
internal pathway of said tube, and exiting said tube to be
electrically accessible outside said vessel.
48. The improvement according to claim 47, further comprising a
sleeve and a bellows seal, wherein said wire is contained within
said sleeve, located within said tube, said sleeve sealing said
wire within said tube, and said bellows seal sealing said wire
between said tube and said anode.
49. The improvement according to claim 48, wherein said wire and
said sleeve include excess length between ends of said tube to
allow vertical displacement of said anode when replacing said
spacer.
50. The improvement according to claim 45, wherein said anode is
connected to said tube by a bayonet connection, and said anode is
engaged or disengaged from said tube by relative rotation
therebetween.
51. The improvement according to claim 45, wherein said tube
penetrates said bottom wall of said cup through a central opening
and is sealed thereto.
52. In an electroplating reactor vessel for use with a wafer
holding assembly which holds a wafer to be electroplated as
electrical cathode, the wafer spaced from an anode arranged within
a cup within the reactor vessel, and which cup holds a level of
process fluid, the improvement comprising: a tube, said tube
supporting said anode from a base of said vessel and defining a
fluid path therein from outside said vessel to inside said cup, and
an electric wire connected to said anode and passing through said
tube and exiting said tube to be electrically connectable from
outside said vessel.
53. The improvement according to claim 52, wherein said tube is
substantially closed at top and bottom ends, said wire passing
through said top and bottom ends, and comprising a sleeve for
sealing said wire from said tube top end to said tube bottom
end.
54. The improvement according to claim 53, further comprising a
bellows seal between said anode and said tube top end, said bellows
seal sealing said wire between said anode and said tube top
end.
55. The improvement according to claim 54, wherein said tube top
and said anode include parts which interengage to define a bayonet
connection, and wherein said bellows seal is resiliently compressed
against said anode when said tube top is engaged to said anode.
56. The improvement according to claim 55, further comprising a
coil spring held within said bellows seal and acting between said
tube top and said bellows seal to resiliently press said bellows
seal to said anode.
57. A reactor vessel for electroplating a semiconductor wafer,
comprising: a reservoir container including a base plate and a
surrounding container side wall upstanding from said base plate; a
cup arranged above said base plate, said cup having a bottom wall
and a surrounding cup side wall upstanding from said bottom wall,
said cup side wall defining a level of process fluid held within
said cup; an anode arranged within said cup below said level; an
anode support arranged beneath said anode and supported from said
base plate; a spacer arranged between said anode support and said
anode.
58. The reactor vessel according to claim 57, comprising a
conductor wire, arranged within said anode support and having a
plug electrically connected to said anode.
59. The reactor vessel according to claim 58, wherein said anode
support includes a tube having an inlet opening for receiving
process fluid, and at least one outlet opening into said cup, and
said tube surrounding said conductor wire.
60. The reactor vessel according to claim 59, comprising a sleeve
surrounding said conductor wire and sealed to said anode and to a
bottom of said tube.
61. The reactor vessel according to claim 60, including a bellows
seal surrounding said plug, and said tube mechanically connectable
to said anode, said anode having a socket for receiving said plug
to make electrical connection thereto, said bellows seal partially
compressed to seal against said anode when said plug is received
into said socket.
62. The reactor vessel according to claim 57, comprising: a
structure for supporting the cup within the reactor vessel, said
structure carried by said surrounding container side wall, said
structure supporting said cup substantially around a perimeter of
said cup.
63. A reactor for electroplating a wafer, comprising: a vessel; a
cup held within said vessel for holding a supply of process fluid,
said cup supported substantially around its perimeter by an inside
wall surface of said vessel; an anode located within said cup and
having a top surface and a bottom surface; a conductor having a
protruding tip and a conducting wire connected to said protruding
tip which is electrically connected to said bottom surface of said
anode by a plug-in connection; a delivery tube extending
substantially from a base of said vessel to a bottom of said anode
and having a top and bottom, said tube mechanically connected to
said anode by a bayonet connection, said delivery tube having a
process fluid inlet, a fluid pathway and a process fluid outlet
into said vessel, said conducting wire passing through said pathway
and said bottom of said delivery tube; and a sleeve and a
resiliently compressible bellows seal; said conducting wire sealed
within said pathway by said sleeve and sealed to said anode bottom
surface by said bellows seal, said bellows seal compressed and said
protruding tip enters said socket when said first bayonet
connection is coupled, said conducting wire exposed outside of said
housing for electrical connection thereto; a diffusion plate and an
anode shield, said anode shield arranged against said bottom
surface of said anode and having brackets extending above said top
surface of said anode, and said diffusion plate carried on said
brackets, spaced at a distance above said top surface of said anode
wherein said diffusion plate and said brackets include
interengaging parts which form bayonet connections.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable
BACKGROUND OF THE INVENTION
[0003] In the production of semiconductor integrated circuits and
other semiconductor articles from semiconductor wafers, it is often
necessary to provide multiple metal layers on the wafer to serve as
interconnect metallization which electrically connects the various
devices on the integrated circuit to one another. Traditionally,
aluminum has been used for such interconnects, however, it is now
recognized that copper metallization may be preferable.
[0004] The semiconductor manufacturing industry has applied copper
onto semiconductor wafers by using a "damascene" electroplating
process where holes, commonly called "vias", trenches and/or other
recesses are formed onto a substrate and filled with copper. In the
damascene process, the wafer is first provided with a metallic seed
layer which is used to conduct electrical current during a
subsequent metal electroplating step. The seed layer is a very thin
layer of metal which can be applied using one or more of several
processes. For example, the seed layer of metal can be laid down
using physical vapor deposition or chemical vapor deposition
processes to produce a layer on the order of 1,000 angstroms thick.
The seed layer can advantageously be formed of copper, gold,
nickel, palladium, or other metals. The seed layer is formed over a
surface which is convoluted by the presence of the vias, trenches,
or other recessed device features.
[0005] A copper layer is then electroplated onto the seed layer in
the form of a blanket layer. The blanket layer is plated to an
extent which forms an overlying layer, with the goal of providing a
copper layer that fills the trenches and vias and extends a certain
amount above these features. Such a blanket layer will typically be
formed in thicknesses on the order of 10,000 to 15,000 angstroms
(1-1.5 microns).
[0006] After the blanket layer has been electroplated onto the
semiconductor wafer, excess metal material present outside of the
vias, trenches, or other recesses is removed. The metal is removed
to provide a resulting pattern of metal layer in the semiconductor
integrated circuit being formed. The excess plated material can be
removed, for example, using chemical mechanical planarization.
Chemical mechanical planarization is a processing step which uses
the combined action of a chemical removal agent and an abrasive
which grinds and polishes the exposed metal surface to remove
undesired parts of the metal layer applied in the electroplating
step.
[0007] The electroplating of the semiconductor wafers takes place
in a reactor assembly. In such an assembly an anode electrode is
disposed in a plating bath, and the wafer with the seed layer
thereon is used as a cathode. Only a lower face of the wafer
contacts the surface of the plating bath. The wafer is held by a
support system that also conducts the requisite cathode current to
the wafer. The support system may comprise conductive fingers that
secure the wafer in place and also contact the wafer in order to
conduct electrical current for the plating operation.
[0008] One embodiment of a reactor assembly is disclosed in U.S.
Ser. No. 08/988,333 filed Sep. 30, 1997 entitled "Semiconductor
Plating System Workpiece Support Having Workpiece-Engaging
Electrodes With Distal Contact Part and Dielectric Cover." FIG. 1
illustrates such an assembly. As illustrated the assembly 10
includes reactor vessel 11 for electroplating a metal, a processing
head 12 and an electroplating bowl assembly 14.
[0009] As shown in FIG. 1, the electroplating bowl assembly 14
includes a cup assembly 16 which is disposed within a reservoir
chamber 18. Cup assembly 16 includes a fluid cup 20 holding the
processing fluid for the electroplating process. The cup assembly
of the illustrated embodiment also has a depending skirt 26 which
extends below a cup bottom 30 and may have flutes open therethrough
for fluid communication and release of any gas that might collect
as the reservoir chamber fills with liquid. The cup can be made
from polypropylene or other suitable material.
[0010] A bottom opening in the bottom wall 30 of the cup assembly
16 receives a polypropylene riser tube 34 which is adjustable in
height relative thereto by a threaded connection between the bottom
wall 30 and the tube 34. A fluid delivery tube 44 is disposed
within the riser tube 34. A first end of the delivery tube 44 is
secured by a threaded connection 45 to an anode 42. An anode shield
40 is attached to the anode 42 by screws 74. The delivery tube 44
supports the anode within the cup. The fluid delivery tube 44 is
secured to the riser tube 34 by a fitting 50. The fitting 50 can
accommodate height adjustment of the delivery tube 44 within the
riser tube. As such, the connection between the fitting 50 and the
riser tube 34 facilitates vertical adjustment of the delivery tube
and thus the anode vertical position. The delivery tube 44 can be
made from a conductive material, such as titanium, and is used to
conduct electrical current to the anode 42 as well as to supply
fluid to the cup.
[0011] Process fluid is provided to the cup through the delivery
tube 44 and proceeds therefrom through fluid outlet openings 56.
Plating fluid fills the cup through the openings 56, supplied from
a plating fluid pump (not shown).
[0012] An upper edge of the cup side wall 60 forms a weir which
limits the level of electroplating solution or process fluid within
the cup. This level is chosen so that only the bottom surface of
the wafer W is contacted by the electroplating solution. Excess
solution pours over this top edge into the reservoir chamber 18.
The level of fluid in the chamber 18 can be maintained within a
desired range for stability of operation by monitoring and
controlling the fluid level with sensors and actuators. One
configuration includes sensing a high level condition using an
appropriate switch 63 and then draining fluid through a drain line
controlled by a control valve (not shown). The out flow liquid from
chamber 18 can be returned to a suitable reservoir. The liquid can
then be treated with additional plating chemicals or other
constituents of the plating or other process liquid, and used
again.
[0013] A diffusion plate 66 is provided above the anode 42 for
providing a more controlled distribution of the fluid plating bath
across the surface of wafer W. Fluid passages in the form of
perforations are provided over all, or a portion of, the diffusion
plate 66 to allow fluid communication therethrough. The height of
the diffusion plate within the cup assembly is adjustable using
threaded diffusion plate height adjustment mechanisms 70.
[0014] The anode shield 40 is secured to the underside of the
consumable anode 42 using anode shield fasteners 74. The anode
shield prevents direct impingement on the anode by the plating
solution as the solution passes into the processing chamber. The
anode shield 40 and anode shield fasteners 74 can be made from a
dielectric material, such as polyvinylidene fluoride or
polypropylene. The anode shield serves to electrically isolate and
physically protect the backside or the anode. It also reduces the
consumption of organic plating liquid additives.
[0015] The processing head 12 holds a wafer W for rotation about a
vertical axis R within the processing chamber. The processing head
12 includes a rotor assembly having a plurality of wafer-engaging
fingers 89 that hold the wafer against holding features of the
rotor. Fingers 89 are preferably adapted to conduct current between
the wafer and a plating electrical power supply and act as current
thieves. Portions of the processing head 12 mate with the
processing bowl assembly 14 to provide a substantially closed
processing volume 13.
[0016] The processing head 12 can be supported by a head operator.
The head operator can include an upper portion which is adjustable
in elevation to allow height adjustment of the processing head. The
head operator also can have a head connection shaft which is
operable to pivot the head 12 about a horizontal pivot axis.
Pivotal action of the processing head using the operator allows the
processing head to be placed in an open or faced-up position (not
shown) for loading and unloading wafer W.
[0017] Processing exhaust gas must be removed from the volume 13.
FIGS. 1 and 2 illustrate an outer vessel side wall 76 that extends
upwardly from the vessel base plate 75 to a top end into which is
nested an intermediate exhaust ring 77 having circumferentially
spaced-apart slots 78 therethrough. The slots 78 communicate
exhaust gas from inside the vessel 13 to a thin annular plenum 79
located between the intermediate exhaust ring 77 and the outer bowl
side wall 76. Surrounding the outer bowl side wall 76 is a vessel
ring assembly 80 which forms with the side wall 76 an external,
annular collection chamber 81. Gas which is collected in the plenum
79 passes through intermittent orifices 82 and into the annular
collection chamber 81. Gas collected in the collection chamber 81
is passed through an exhaust nozzle 83 to be collected and
recycled.
[0018] The above described apparatus can suffer from some
drawbacks. The threaded connection 45 of the anode and the delivery
tube may introduce some risk of thread damage during maintenance or
installation of a new anode onto the delivery tube. This type of
construction also makes the rotational engagement and installation
of, or the disengagement and removal of, the anode to/from the
delivery tube difficult and time consuming, due to the heavy weight
of the anode and the tight clearances between the anode 42 and the
cup sidewall 60. The threaded connection requires a sufficient
number of anode rotations for a complete threaded engagement during
assembly, or complete threaded disengagement during
disassembly.
[0019] Additionally, in electroplating processes using a consumable
anode, it is desired to have an anodic film deposited on a surface
of the anode. This film is applied to the anode before wafer
processing. However, this anodic film is very fragile and any hand
or tool contact with the anodic film during engagement or
disengagement is likely to damage the film, which must then be
re-grown. This makes the threaded, rotational manipulation and
handling of the anode during installation or removal particularly
difficult. Also, handling the anode assembly or the diffusion plate
during the assembly and disassembly can contaminate surfaces of the
anode assembly, the diffusion plate, or other inside surfaces
within the volume 13.
[0020] The threaded height adjustment of the diffusion plate using
threaded height adjustment mechanisms 70 also requires a time
consuming operation to precisely install the diffusion plate to the
anode. A plurality of securements, such as Allen head screws, are
required to be removed to disassemble the diffusion plate from the
anode and reinstalled during reassembly. This is an important
consideration since the diffusion plate must be removed routinely
to inspect anodic film formation on the anode. The adjustment of
the plural screw mechanisms can also introduce height and level
inaccuracies of the diffusion plate with respect to the anode
and/or reactor cup.
[0021] Also, the cup assembly located inside the reactor vessel is
supported by an adjustable threaded engagement with the riser tube.
The threaded engagement may introduce cup height and level
misadjustments.
[0022] The threaded height adjustment of the anode assembly within
the cup, by adjusting the delivery tube, can introduce height and
levelness misadjustments. Additionally, the delivery tube being
vertically adjustable by loosening of a locking nut located below
the reactor vessel, requires access to both the top side of the cup
for viewing the anode height adjustment, and the bottom side of the
vessel to loosen this locking nut. If the reactor vessel is
supported on a deck this requires access to both above and below
the deck. Additionally, the delivery tube being vertically
adjustable at the reactor vessel base plate requires a more complex
seal mechanism between the delivery tube and the anode post at the
vessel base plate. Also, the delivery tube serving the dual
function of being a liquid conduit and an electrical conductor
requires the tube to be constructed of a metallic material which is
conductive yet substantially inert to the process chemistry. Such a
conduit has been composed of titanium, which is costly.
[0023] The present inventors have recognized that it would be
advantageous to provide a reactor vessel having an improved
connection arrangement between anode and diffusion plate, and
between anode and anode support structure to avoid some of the
foregoing problems. Further, the inventors have recognized that it
would be advantageous to provide a reactor vessel arrangement that
facilitates easier assembly and disassembly of diffusion plate,
anode, anode support structure and anode electrical conductor than
found in the foregoing system. Still further, the present inventors
have recognized that it would be advantageous to provide a reactor
vessel which eliminates threaded connections to as great a degree
as possible.
[0024] The inventors have recognized that it would be advantageous
to provide a reactor vessel having: an improved mechanical
connection arrangement between anode and delivery tube, an improved
electrical connection between anode and an outside electrical power
source, an improved accessibility for adjusting elements of the
reactor vessel, an improved accuracy of vertical adjustment between
the anode and the cup, and an improved accuracy of vertical and
level adjustment of the cup within the reactor vessel.
BRIEF SUMMARY OF THE INVENTION
[0025] An improved reactor vessel is disclosed herein. The improved
reactor vessel includes a reservoir container having a base with a
surrounding container sidewall upstanding from the base. A cup is
arranged above the base, the cup having a bottom wall and a
surrounding cup sidewall upstanding from the bottom wall, the cup
sidewall defining a level of process fluid held within the cup. The
cup is supported within the reactor vessel on the surrounding
container sidewall substantially around a perimeter of the cup.
Unlike the reactor vessel of FIG. 1, which supports the cup at a
central location by threaded engagement with the riser tube, the
cup of the present invention is supported around its outside
perimeter at a precise and stable level with respect to the reactor
vessel. An electrode plate, such as a consumable anode, is arranged
within the cup below the fluid level.
[0026] The reactor vessel includes bayonet style connections
between an anode assembly and a diffusion plate, and a bayonet
style connection between an anode support structure and the anode
assembly. A tool is provided which simplifies the installation and
removal of the diffusion plate and the anode assembly, while
minimizing the risk of contamination or damage to the anode
assembly, diffusion plate, or other surfaces within the reactor
vessel.
[0027] In one embodiment, the reactor vessel includes as separate
pieces, an anode electrical conductor and a fluid delivery tube.
The delivery tube functions as the anode support structure for
adjustably supporting the anode assembly, and as a conduit for
delivering process fluid into the cup surrounding the anode. A
corrugated sleeve or tube seals the electrical conductor within the
delivery tube.
[0028] The fluid delivery tube is fixed at its top end to the anode
assembly by a bayonet connection. A protruding tip of the conductor
which extends above the delivery tube engages a socket formed in
the anode. The engagement of the tip into the socket occurs
simultaneously with the engagement of the bayonet connection. A
spring within the bellows seal resiliently holds the bayonet
connection in its engaged condition and assists in maintaining a
sealed connection between the bellows seal and the anode.
[0029] The delivery tube is sealed to the base and extends through
the cup bottom wall to support the anode assembly from the base.
The tube has a substantially closed bottom and a top. The anode
electrical conductor includes a conductor wire which is arranged
within the tube and passes through the tube bottom and top, the
conductor wire being connected to the protruding tip. The tube
includes an inlet opening for receiving process fluid, and at least
one outlet opening into the cup.
[0030] The reactor vessel includes a fixed incremental vertical
adjustment and level adjustment between the anode assembly and the
reactor cup. A spacer (or spacers) having a desired thickness is
(are) interposed between the anode and the delivery tube to set the
anode height within the cup. The spacer is C-shaped so as to be
installable without complete dismantling of the electrical
conductor assembly. The electrical conductor includes an excess
length within the delivery tube for the purpose of allowing room
for the removal and installation of the C-shaped spacer during
level adjustment of the cup.
[0031] The anode assembly includes an anode shield that carries the
anode. A plurality of brackets, preferably formed as a unitary
structure with the anode shield, extend upwardly from the anode.
The diffusion plate is connected to the plurality of brackets by a
bayonet connection at each bracket. The diffusion plate is thus
held elevated above the anode.
[0032] The reactor vessel configuration simplifies construction and
assembly thereof. The anode assembly can easily be removed from the
fluid delivery tube and the electrical conductor disconnected from
the anode due to the bayonet connection between the delivery tube
and the anode, and the tip/socket connection between the electrical
conductor and the anode. A threaded connection between anode
assembly and delivery tube is eliminated. Misadjustment of the
anode assembly caused by the threaded connection between delivery
tube and the anode assembly is eliminated. Assembly drawbacks
associated with threaded connections such as damaged threads, and
time consuming assembly/disassembly are reduced or avoided. The
anode assembly need only be depressed, turned and withdrawn to be
disengaged and removed from the reactor vessel.
[0033] The level adjustment of the anode can be accomplished
entirely with access only on a top side of the reactor. No
loosening operation or threaded adjustment on a bottom side of the
reactor is required. The anode can be removed and installed from a
top side of the reactor. The protruding tip and its associated
flange can then be lifted up so that the spacer can be exchanged
with a replacement spacer or spacers, for a more precise height or
level adjustment.
[0034] By replacing the delivery tube having a threaded vertical
adjustment at the vessel bottom wall with a fixed delivery tube
having no relative movement between the vessel bottom wall and the
tube, a reduced seal mechanism complexity is achieved for the
delivery tube at the vessel bottom wall. The delivery tube can be
permanently sealed to the vessel bottom wall without provision for
relative vertical adjustment between the delivery tube and an anode
post at the bottom wall.
[0035] A conductor wire sealed from the process fluid by a
dielectric sleeve is used in combination with a dielectric material
delivery tube resulting in an effective and more cost efficient
construction. By separating the process fluid delivery function
from the electrical conduction function, the need for a costly
titanium delivery tube is eliminated.
[0036] The diffusion plate is more easily removed and reinstalled
by virtue of the bayonet connections at each of the brackets of the
anode shield. The small screws which were previously required to be
removed with, for example, an Allen wrench, to remove the diffusion
plate from the diffusion plate height adjusting mechanism, are
eliminated. Additionally, the threaded height adjustment mechanisms
are eliminated which could otherwise adversely vary the installed
height or levelness of the diffusion plate.
[0037] A multi-function tool is also provided which functions to
engage and install/remove the diffusion plate from the anode
assembly, and also to engage and install/remove the anode assembly
from the fluid delivery tube. The tool reduces or eliminates
handling of the diffusion plate and the anode assembly during
installation or removal which can cause anodic film damage,
contamination and damage to the diffusion plate or anode assembly
or the vessel interior.
[0038] An additional advantage of the bayonet connections of the
diffusion plate and the anode in combination with the
multi-function tool is the fact that a reduced overhead clearance
is required to remove the diffusion plate and the anode. In
comparison, to manually detach and remove, and later reinstall, the
diffusion plate and anode of the reactor shown in FIG. 1, the
entire head assembly including the lift and rotate mechanism which
manipulates the rotor must be removed. After the reactor is
reassembled and the head assembly is reinstalled, the wafer loading
robot or manipulator (not shown) which loads wafers onto the rotor,
must be reinstructed or recalibrated to ensure an accurate
placement of wafers on the rotor. This step is time consuming and
costly. Because the diffusion plate and anode assembly of the
present invention can be manipulated and removed using simplified
hand manipulations with the multi-function tool, it is possible
that the lift and rotate mechanism can remain in place and only the
rotor removed from the processing head to obtain enough access for
diffusion plate and anode assembly removal and reinstallation. It
is anticipated that this advantage of the invention will result in
a reduced disassembly, inspection, and reassembly time during
maintenance of the reactor vessel.
[0039] Numerous other advantages and features of the present
invention will become readily apparent from the following detailed
description of the invention and the embodiments thereof, from the
claims and from the accompanying drawings in which details of the
invention are fully and completely disclosed as part of this
specification.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0040] FIG. 1 is an exploded partially sectional view of a reactor
vessel and processing head;
[0041] FIG. 2 is an enlarged fragmentary sectional view taken from
FIG. 1;
[0042] FIG. 3 is a perspective view of a reactor vessel constructed
in accordance with one embodiment of the present invention;
[0043] FIG. 4 is an exploded perspective view of the reactor vessel
of FIG. 3;
[0044] FIG. 5 is a top view of the reactor vessel of FIG. 3;
[0045] FIG. 6 is a bottom view of the reactor vessel of FIG. 3;
[0046] FIG. 7 is a sectional view taken generally along line 7-7 of
FIG. 5;
[0047] FIG. 7A is an enlarged fragmentary sectional view from FIG.
7;
[0048] FIG. 8 is a sectional view taken generally along line 8-8 of
FIG. 5;
[0049] FIG. 9 is a sectional view taken generally along 9-9 of FIG.
5;
[0050] FIG. 10 is an enlarged perspective view of a fluid delivery
tube shown in FIG. 7;
[0051] FIG. 11 is an exploded perspective view of one embodiment of
an anode conductor assembly;
[0052] FIG. 12 is a sectional view of the anode conductor assembly
of FIG. 11;
[0053] FIG. 13 is an enlarged fragmentary sectional view of the
anode conductor assembly of FIG. 12;
[0054] FIG. 14 is a top perspective view of a diffusion plate and
anode removal/installation tool constructed in accordance with one
embodiment of the present invention;
[0055] FIG. 15 is a bottom perspective view of the tool of FIG.
14;
[0056] FIG. 16 is a fragmentary bottom perspective view of an
alternate lock pin arrangement for the tool in FIG. 14;
[0057] FIG. 17 is a perspective view of one embodiment of an anode
shield as used in the reactor vessel of FIG. 3;
[0058] FIG. 18 is a fragmentary, enlarged perspective view of the
anode shield of FIG. 17;
[0059] FIG. 19 is an exploded perspective view of one embodiment of
a diffusion plate as used in the reactor vessel of FIG. 3;
[0060] FIG. 20 is a perspective view of the diffusion plate of FIG.
19; and
[0061] FIG. 21 is a bottom perspective view of one embodiment of a
bottom ring portion of the diffusion plate of FIG. 19.
DETAILED DESCRIPTION OF THE INVENTION
[0062] While this invention is susceptible of embodiment in many
different forms, there are shown in the drawings and will be
described herein in detail specific embodiments thereof with the
understanding that the present disclosure is to be considered as an
exemplification of the principles of the invention and is not
intended to limit the invention to the specific embodiments
illustrated.
[0063] FIGS. 3-6 illustrate a reactor vessel 100 which is to be
used in cooperation with a processing head 12 (as shown in FIG. 1).
The processing head 12 may, for example, be of the type disclosed
in U.S. Ser. No. 08/988,333 filed Sep. 30, 1997 entitled:
"Semiconductor Plating System Workpiece Support Having
Workpiece-Engaging Electrodes With Distal Contact Part and
Dielectric Cover" herein incorporated by reference. The processing
head holds a wafer to be processed within a substantially closed
processing volume 103 of the reactor vessel 100, and rotates the
wafer during processing. The vessel 100 is shown without a vessel
exhaust ring assembly for clarity to illustrate the underlying
parts. It is to be understood that the outer vessel exhaust ring
assembly 80 and exhaust nozzle 83 as shown for example in FIG. 1
would be mounted around the vessel 100 as shown for example in FIG.
2.
[0064] The reactor vessel 100 includes a rotor supporting ring or
rim 110 mounted on an inner exhaust ring 124 which is carried on a
reservoir container 120. A diffusion plate 112 is carried by an
anode shield 116 which, in turn, carries an anode 114. The anode
114 is preferably a consumable anode composed of copper or other
plating material. The anode 114 and the anode shield 116 are
fastened together forming an anode assembly 117. A reactor cup
assembly 118 is supported on, and partially held within, a
reservoir container assembly 120. An anode electrical conductor
assembly 122 extends vertically through the reservoir container 120
and makes electrical connection with the anode 114 as described
below. A de-plating electrode 123 in the form of a ring 123a and a
contact support 123b allows for periodic de-plating of
wafer-engaging fingers 89 (shown in FIG. 1).
[0065] FIGS. 7-9 illustrate the rotor support ring 110 nesting into
the exhaust ring 124 of the reservoir container assembly 120. The
cup assembly 118 includes a cup inner sidewall 130 defining at its
upper edge 130a an overflow weir, and a cup outer sidewall 131
which extends upward to a bottom 110a of the rotor support ring
110. The inner and outer sidewalls 130, 131 are radially connected
by intermittent webs 132 formed integrally with the sidewalls 130,
131. A container or "cup" 139 for holding process fluid is formed
by a cup bottom wall 138 and the inner sidewall 130.
[0066] The reservoir container assembly 120 includes a surrounding
reservoir sidewall 140 that is sealed to a base plate 142 and
supports the exhaust ring 124 at a top thereof. The cup assembly
118 is supported by an outer edge 131b of the outer sidewall 131
resting on a ledge 124a of the exhaust ring 124 which, in turn, is
supported by a top edge 140a of the vessel sidewall 140. Thus the
elevation and level of the cup assembly 118 is preferably fixed,
i.e., it is non-adjustable with respect to the reservoir 120.
[0067] The anode 114 is connected by fasteners (as shown for
example in FIG. 1) to the anode shield 116. The anode 114 is
supported within the cup sidewall 130 by an anode support structure
such as a fluid delivery tube or "anode post" 134. The anode post
134 is in the form of a cylindrical tube (see FIG. 10) having top
and bottom ends substantially closed as described below. The anode
post 134 extends through an opening 143 through the reservoir base
plate 142 and through an opening 136 in the cup bottom wall 138.
The anode post 134 is sealed to the cup bottom wall 138 around the
opening 136 with an O-ring 137. Further, the anode post is sealed
to the base plate 142 around the opening 143 by plastic welding or
other sealing technique.
[0068] Extending downwardly from the cup sidewall 130 is a fluted
skirt 148 having a plurality of slots 150 for allowing passage of
process fluids. Through the base plate 142 of the reservoir
container 120 passes an overflow standpipe 154 having an open end
155 for receiving process fluid. Also, connected to the bottom wall
142 is a process outlet 158 for the draining of process fluid from
the reservoir container 120. It is to be understood that the
standpipe 154 and the process outlet 158 would be connected to
process piping to deliver process fluid to a recycling system or
other process fluid system. In this regard, a precise control of
the process fluid level in the container 120 can be maintained
through use of a high process fluid level switch 170 and a low
process fluid level switch 171 within the container 120 which open
and close a control valve (not shown) connected to the outlet
158.
[0069] The anode electrical conductor assembly 122 includes at a
bottom end thereof, a fitting 190 having a bottom region 191
threaded for receiving a nut 192. The fitting 190 can be firmly
tightened to a bottom wall 200 of the anode post 134. The fitting
190 includes a top flange 190a with an O-ring seal element 190b
which is drawn into sealing engagement with the top surface 200a of
the wall 200 by advancement of the nut 192 on the fitting 190.
[0070] The anode post 134 includes an internal volume 204 in fluid
communication with outlet openings 206 (shown in FIG. 8), and with
a bottom supply nozzle 208 (shown in FIG. 8), for delivering
process fluid into the cup 139, from an outside source of process
fluid. The anode post 134 is closed at a top end by a top cap
194.
[0071] The anode electrical conductor assembly 122 includes a
corrugated sleeve 210 sealed by a first coupling 212 to a neck 213
of the fitting 190. The sleeve surrounds a conductor wire 221 shown
schematically as a line. The wire 221 is not shown in FIGS. 8 and 9
for clarity. The corrugated sleeve 210 extends upwardly and is
sealed to a neck 225 of a fitting 195 of the top cap 194 by a
second coupling 224.
[0072] FIG. 7A illustrates the sealing arrangement used at the
couplings 212, 224. The necks 213, 225 receive a pre-flared,
non-corrugated end 210b (or 210c) of the corrugated sleeve 210
which is then compressed by a tapered inside surface 225a of the
respective coupling 212, 224, against a tapered outer surface 225b
of the respective necks as the coupling threads 226 are advanced on
respective fitting threads 227. This sealing arrangement is similar
to commercially available flared fittings.
[0073] The top cap 194 includes a support ring 240. The support
ring guides a conductor tip 220 held vertically within a central
aperture of the support ring. The tip 220 is electrically connected
to the conductor wire 221. The cap 194 further includes a
surrounding guide ring 242 around which is carried a bellows seal
260 which extends upwardly from the cap 194. The bellows seal
surrounds the tip 220 and, in its relaxed state, extends to a
position upwardly thereof. The bellows seal 260 includes a top
opening 262 in registry with the tip 220, and a surrounding groove
260c for holding an O-ring seal element 260b (see FIGS. 11-13).
[0074] The top cap 194 is substantially cross-shaped in plan view,
having a plurality of fastener holes 194a (see FIG. 11). A
substantially circular, dished attachment plate 264 is arranged
coaxially with the top cap 194 and includes a central aperture 266
for receiving the guide ring 242 of the top cap 194. The attachment
plate 264, and the cap 194 are fastened together and to the post
134, via an interposed spacer 228, by four fasteners 229. The
fasteners are fit into four holes 264a through the attachment plate
264 (shown in FIG. 4), the four fastener holes 194a through the top
cap 194, four holes 228a through the spacer (shown in FIG. 4), and
then threaded into four threaded holes 134a of the anode post
(shown in FIG. 10). The spacer 228 is selected for a precise
thickness to set the elevation of the anode 114 with respect to the
cup assembly 118, particularly with respect to the top edge 130a of
the sidewall 130.
[0075] The attachment plate 264 is connected to the anode assembly
by a bayonet connection. A bayonet connection is characterized as
one in which one part is connected to another part by first a
movement toward each other and then a second relative rotational
movement between the parts. The attachment plate 264 includes a
plurality of spaced apart, radially extending tabs 265. During
installation of the anode assembly, the tabs 265 vertically enter
vertical slots 267 (see FIGS. 9, 17 and 18) formed in the anode
shield 116, and upon turning of the anode assembly 117 from above,
the tabs 265 are advanced relatively in circular, substantially
horizontal slots 268 formed between the anode 114 and the shield
116. The horizontal slots 268 each terminate in a tab-receiving
recess 269 which restrains the tabs from rotational disengagement
once completely installed. Spring force from a bellows spring
(described below) holds the tabs 265 within the recesses 269.
During engagement of the tabs 265, the bellows 260 and bellows
spring are vertically compressed as the tip 220 is plugged into a
socket 270 formed in the anode 114 to make a solid "plug-in" or
"plug-and-socket" electrical connection thereto.
[0076] To disengage the anode assembly from the attachment plate
264, the anode is pressed downwardly to elevate and disengage the
tabs 265 from the recesses 269, and the anode is turned or rotated
to align the tabs with the vertical slots 267. The anode assembly
can then be withdrawn upwardly. The tip 220 will be pulled free
from the socket 270 and resiliently open up once free of the
socket.
[0077] It can be observed that the height adjustment of the anode
can be set entirely from above. First, the anode 114 and shield 116
are removed from the attachment plate 264. Second, the attachment
plate is removed from the post 134 by removal of the fasteners 229.
Third, the cap 194 is lifted upwardly, and the spacer 228 is
replaced with a spacer having a desired thickness dimension. As
shown in FIG. 4 the spacer 228 is C-shaped to facilitate
replacement around the conductor assembly 122 without complete
disassembly thereof, i.e., there is no need to remove the tip 220
or the top cap 194 from the conductor wire.
[0078] As illustrated particularly in FIGS. 8 and 9, the diffusion
plate 112 is connected to intermittently arranged upstanding
bracket members 274 using bayonet connections. As shown in FIGS. 9
and 21, a connector ring 278 of the diffusion plate 112 has a
C-shaped cross-section forming a channel 279. Each bracket 274
includes a vertical leg 275 and a radially, outwardly extending tab
member 280. During installation, each tab member 280 enters a wide
slot or recess 281 through the bottom leg 279a of the C-shaped
cross-section. Upon relative turning between the ring 278 and the
bracket 274, each vertical leg 275 of each bracket 274 resiliently
passes a detent 282 and enters a more narrow slot or recess 283.
Each detent 282 thus resiliently locks a bracket member 274 to the
connector ring 278. To remove the diffusion plate 112 from the
anode assembly 117, the plate is rotated in an opposite direction.
The legs 275 resiliently deflect radially inwardly a sufficient
amount to pass the detents 282. Finally, the tab members 280 are
withdrawn through the recesses 281.
[0079] FIGS. 11-13 illustrate the construction of one embodiment of
the anode conductor assembly in more detail. As illustrated, the
anode tip 220 has a profile which compresses when installed in the
socket 270 of the anode. The tip includes a small diameter distal
end region 220a, a wide central region 220b, and a narrow base
region 220c. The base region 220c terminates at a flange or stop
220d which sets the extension of the tip 220 from the support ring
240 of the cap 194.
[0080] The tip 220 includes a soldering connection or crimping
region 220e at a bottom end thereof that is used for connecting it
to the conductor wire 221 (shown schematically in FIG. 12). The
conductor wire 221 extends downwardly from the tip 220 through the
fitting 195 of the cap 194, the corrugated sleeve 210, and the
bottom fitting 190. From the bottom fitting 190, the wire 221
extends externally of the reactor vessel 100 for connection to a
plating power supply.
[0081] The corrugated sleeve 210 includes a corrugated length 210a
between the couplings 212, 224 and a first non-corrugated portion
210b which over-fits the neck 225 of the fitting 195, and a second
non-corrugated portion 210c which over-fits the neck 213 of the
fitting 190 as illustrated in FIG. 7A. The couplings 212, 224, by
progressive threaded tightening onto the respective necks 213, 225,
seal the non-corrugated regions 210b, 210c onto the fittings 190,
195 to form a sealed configuration around the conductor wire within
the anode post 134.
[0082] FIG. 11 illustrates the assembly of the conductor assembly
122, absent the wire conductor for clarity. The O-ring 260b is
arranged to fit within a channel 260c of the bellows 260. Another
O-ring 242a is arranged to fit within a channel 242b (see FIG. 13)
of the guide ring 242 to seal the bellows 260 to the top cap
194.
[0083] As illustrated in FIG. 13, a bellows coil spring 290 is fit
within the bellows 260 and the top cap 194. The spring 290 is fit
within an annular channel 292 formed between the guide ring 242 and
the support ring 240. The spring 290 urges the anode assembly away
from the attachment plate 264 to resiliently seat the tabs 265 in
the tab-receiving recesses 269. Additionally, the spring acts to
press the O-ring 260b into the anode to effect a tight seal
thereto.
[0084] FIG. 14 illustrates a multi-function diffusion plate and
anode removal/installation tool 300 of the present invention. The
tool 300 includes a disc structure 302 having a central hole 304.
Bridging across the central hole is a handle 306. The handle is
held to the disc structure by fasteners 307 (shown in FIG. 15). A
lock pin 308 having a grip head 310 penetrates a pin receiving hole
312 through the disc structure 302.
[0085] As illustrated in FIG. 15, the disc structure includes four
L-shaped hook arms 320, each having a vertical leg 322 and a
radially inwardly directed detent or hook portion 324. In
operation, the hook arms 320 extend downwardly. The hook arms 320
are configured and arranged to engage bayonet recesses 330 formed
through an outside of a top perforated plate 112a of the diffusion
plate 112 as illustrated in FIGS. 5, 19 and 20. Each recess 330
includes a wide region 332 for receiving a hook portion 324, and
two narrow regions 334 for snugly receiving a leg 322 into a locked
position (in either direction depending on whether removal or
installation is taking place). When the leg 322 moves in this
position, the hook portion 324 is located below the top perforated
plate 112a. The tool with engaged diffusion plate can then be
rotated in one direction to remove the diffusion plate 112, or
rotate in an opposite direction to install the diffusion plate 112
from or onto the brackets 274.
[0086] The tool 300 also serves as an anode assembly
removal/installation tool once the diffusion plate 112 has been
removed. On a bottom surface of the tool 300 are located four
bracket/engaging recesses 340 that are spaced apart to mate with
the brackets 274 of the anode shield 116. Each recess 340 includes
a recess region 342 for receiving the radially turned end of the
bracket 274 therethrough. A further recess region 344 is defined at
least in part, by a radially extending ledge 346. Extending
vertically from the disc structure 302 are four guide pins 348.
Each guide pin 348 is radially spaced from a respective ledge 346
by a distance approximately equal to, or greater than, a radial
thickness of a respective bracket vertical leg 275. Thus, in
operation, the tool 300 is placed onto the anode assembly 117 with
each bracket 274 received into one of the wide recess regions 342.
The tab member 280 of each bracket 274 is located above a
respective ledge 346. The tool is then rotated relative to the
anode such that the vertical leg 275 of each bracket 274 slides
circumferentially between a respective ledge 346 and a respective
guide pin 348. The tab member 280 of each bracket 274 is thus
captured above the respective ledge 346.
[0087] The lock pin 308 is operated by force of gravity to fall to
a position behind one of the brackets 274 which has passed into the
narrow recess region 344. The lock pin 308 thus prevents
inadvertent reverse rotation of the tool relative to the anode.
This prevents accidental separation of the tool and the relatively
heavy anode assembly during removal, assembly or transporting of
the anode assembly. The lock pin 308 is preferably formed of two
pieces: a bottom piece 308a, having a tool engageable head 350
connected to a first barrel 352, and a top piece 308b which
includes the gripping head 310 connected to a second barrel 354.
The first barrel has a male threaded extension (not shown) which is
engaged by a female threaded socket (not shown) of the second
barrel. Thus relative rotation of the first and second barrels can
separate or join the two pieces 308a, 308b at a seam 308c for
disassembly or assembly of the pin 308. The gripping head 310 and
the engageable head 350 allow retention of the pin to the
interposed disc structure 302, while still allowing vertical
reciprocation with respect thereto.
[0088] Additionally, as illustrated in FIG. 16, the lock pin can
alternately be configured to allow lifting of the lock pin by
sliding pressure (rather than manual lifting) of the respective
bracket 274 during engagement of the tool to the anode assembly.
The pin is designed to be lifted by the top surface of the tab 274
as it enters the slot 342 and then falls into position upon
rotation of the handle. The lock pin however can require manual
lifting of the pin to disengage the tool from the anode assembly,
by relative rotation therebetween. This is accomplished, for
example, by a ratchet tooth shaped pin 350, wherein the ratchet
tooth shaped pin would provide a slanted surface 352 facing an
engagement direction with the bracket 274. The pin 350 includes a
vertical surface 354 facing a tool disengagement direction. A
retaining mechanism such as a detent (not shown) or a two piece
construction with enlarged heads (such as described with regard to
the pin 308) can be provided on the shaped pin to prevent
separating of the shaped pin from the interposed disc structure
302. The retaining mechanism would allow vertical reciprocation of
the pin with respect to the disc structure.
[0089] The tool 300 thus provides an effective means to disassemble
and reassemble the diffusion plate and anode assembly from the
vessel. The tool also reduces contact, damage and contamination of
the anode and anode film.
[0090] FIGS. 19-20 illustrate the diffusion plate 112 in detail.
The diffusion plate includes the top perforated plate 112a which is
attached by fasteners (not shown) through four fastener hole pairs
297a, 297b to the connector ring 278, capturing a spacer ring 298
therebetween. The holes 297b are threaded to engage the fasteners.
The spacer ring 298 has a smaller outside diameter D1 than an
inside diameter D2 between diametrically opposing wide recesses 332
to ensure noninterference of the spacer ring 298 with the hook arms
320 of the tool 300 during installation or removal of the diffusion
plate. The thickness of the spacer ring 298 provides a vertical
space below the perforated plate 112a, particularly below the
bayonet recesses 330, for the hook portion 324 to be received.
[0091] In the disclosed embodiment, the cup assembly 118, the anode
post 134, the reservoir container 120, the anode shield 116, the
diffusion plate 112, the exhaust ring 124, the rotor support ring
110, the corrugated sleeve 210, the spacer 228, the fasteners 229,
the top cap 194, the fitting 190, the nut 192, the couplings 212,
224, and the attachment plate 264, are all preferably composed of
dielectric materials such as natural polypropylene or
polyvinylidene fluoride. The conductor wire 221 is preferably
composed of copper or another appropriate conductor, as is the tip
which also can be gold plated for enhanced electrical contact. The
bellows seal 260 is preferably composed of a Teflon material. The
bellows spring is preferably composed of stainless steel. The
various O-rings are preferably composed of an acid compatible
fluoro-elastomer, depending on the process fluid.
[0092] Numerous modifications may be made to the foregoing system
without departing from the basic teachings thereof. Although the
present invention has been described in substantial detail with
reference to one or more specific embodiments, those of skill in
the art will recognize that changes may be made thereto without
departing from the scope and spirit of the invention as set forth
in the appended claims.
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