U.S. patent application number 14/505184 was filed with the patent office on 2015-01-22 for substrate processing including correction for deposition location.
The applicant listed for this patent is Intermolecular, Inc.. Invention is credited to Jeremy Cheng, Indranil De, Ho Yin Owen Fong, Zhendong Hong, Dan Wang.
Application Number | 20150025670 14/505184 |
Document ID | / |
Family ID | 51845713 |
Filed Date | 2015-01-22 |
United States Patent
Application |
20150025670 |
Kind Code |
A1 |
Cheng; Jeremy ; et
al. |
January 22, 2015 |
Substrate Processing Including Correction for Deposition
Location
Abstract
Substrate processing including correction for deposition
location is described, including a combinatorial processing chamber
that incorporates the correction. The combinatorial processing
chamber can be used to process multiple regions of a substrate
using different processing parameters on different regions. For
example, one region can have one material deposited on it and
another region can have a different material deposited on it,
although other combinations and variations are possible. The
combinatorial processing chamber uses a rotating and revolving
substrate pedestal to be able to deposit on all locations or
positions on a substrate. The combinatorial processing chamber uses
a correction factor that accounts for variations in alignment
and/or configuration of the processing chamber so that the actual
location of deposition of a region is approximately the same as a
desired location of deposition.
Inventors: |
Cheng; Jeremy; (Cupertino,
CA) ; De; Indranil; (Mountain View, CA) ;
Fong; Ho Yin Owen; (San Jose, CA) ; Hong;
Zhendong; (San Jose, CA) ; Wang; Dan;
(Saratoga, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Intermolecular, Inc. |
San Jose |
CA |
US |
|
|
Family ID: |
51845713 |
Appl. No.: |
14/505184 |
Filed: |
October 2, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12651172 |
Dec 31, 2009 |
8882917 |
|
|
14505184 |
|
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|
Current U.S.
Class: |
700/114 |
Current CPC
Class: |
C23C 14/54 20130101;
B01J 2219/00326 20130101; B01J 2219/00695 20130101; C23C 14/505
20130101; B01J 2219/0043 20130101; B01J 2219/00689 20130101; C23C
14/042 20130101; B01J 2219/00536 20130101; B01J 2219/00443
20130101; B01J 2219/00612 20130101; G05B 19/402 20130101; B01J
19/0046 20130101; G05B 2219/45031 20130101; B01J 2219/00693
20130101 |
Class at
Publication: |
700/114 |
International
Class: |
G05B 19/402 20060101
G05B019/402 |
Claims
1. A method comprising: obtaining a correction factor, wherein the
correction factor accounts for offsets of a rotation center of a
substrate pedestal, a revolution center, and a center of a first
substrate; using the correction factor, determining at least one of
a first rotation angle for rotating the substrate pedestal holding
the first substrate, or a first revolution angle for revolving a
processing aperture relative to the first substrate for positioning
the processing aperture relative to the first substrate;
positioning the processing aperture relative to the first substrate
using at least one of rotating the substrate pedestal by the first
rotation angle, or revolving the processing aperture by the first
revolution angle; and after positioning, processing a first region
of the first substrate.
2. The method of claim 1, wherein the processing the first region
comprises using physical vapor deposition (PVD).
3. The method of claim 1, further comprising: determining the
correction factor comprises: processing multiple regions of a
second substrate; determining correction vectors to calculate
offsets of actual locations of the multiple regions compared to
desired locations of the multiple regions; and calculating the
correction factor based on the correction vectors.
4. The method of claim 3, further comprising measuring the actual
locations of the multiple regions of the second substrate and
comparing the actual locations of the multiple regions compared to
the desired locations of the multiple regions.
5. The method of claim 3, wherein the correction vectors are
determined using an iterative two-dimensional Newton's method.
6. The method of claim 1, further comprising processing a second
region on the first substrate.
7. The method of claim 6, wherein the first region and the second
region are processed using different processing parameters.
8. The method of claim 6, wherein processing the first region forms
a first material, wherein processing the second region forms a
second material, and wherein the first material and the second
material have different compositions.
9. The method of claim 6, further comprising, after processing the
first region and prior to processing the second region,
repositioning the processing aperture relative to the first
substrate using at least one of rotating the substrate pedestal by
the first rotation angle, or revolving the processing aperture by
the first revolution angle.
10. The method of claim 6, further comprising, prior to processing
the second region on the first substrate, using the correction
factor, determining at least one of a second rotation angle for
rotating the substrate pedestal holding the first substrate, or a
second revolution angle for revolving the processing aperture
relative to the first substrate for positioning the processing
aperture relative to the first substrate for processing the first
substrate; and positioning the processing aperture relative to the
first substrate using at least one of rotating the substrate
pedestal by the second rotation angle, or revolving the processing
aperture by the second revolution angle.
11. The method of claim 1, wherein the first rotation angle and the
first revolution angle are both obtained using the correction
factor.
12. The method of claim 1, wherein positioning the processing
aperture relative to the first substrate uses rotating the
substrate pedestal by the first rotation angle and revolving the
processing aperture by the first revolution angle.
13. The method of claim 1, wherein the correction factor comprises:
x.sub.f=r.sub.1 cos .phi..sub.1+r.sub.a cos .phi..sub.2-x.sub.w and
y.sub.f=r.sub.1 sin .phi..sub.1+r.sub.a sin .phi..sub.2-y.sub.w
wherein (x.sub.f, y.sub.f) is the correction factor in Cartesian
coordinates, (r.sub.1, .phi..sub.1) is a position of the processing
aperture above the first substrate after at least one of a rotation
about a first axis and a revolution around a second axis to
position the aperture in polar coordinates, (r.sub.a, .phi..sub.a)
is a vector between the first axis and the processing aperture,
(x.sub.w, y.sub.w) is the first offset,
.phi..sub.2=.phi..sub.a+.theta.-.omega., .theta. is an angle of
rotation of the substrate pedestal, and .omega. is an angle of
revolution of the processing aperture.
14. The method of claim 1, further comprising determining alignment
of the first substrate using an imaging device.
15. The method of claim 1, wherein the processing aperture is
formed in a process kit shield enclosing a plurality of deposition
guns.
16. The method of claim 15, wherein the process kit shield
comprises a slide cover plate and wherein, during processing the
first region of the first substrate, the slide cover plate seals at
least one of the plurality of the deposition guns.
17. The method of claim 15, wherein each of the plurality of
deposition guns is operable to move in a direction substantially
normal to the first substrate.
18. The method of claim 1, wherein rotating the first substrate and
revolving the processing aperture allow to position the processing
aperture over any location of the first substrate.
19. The method of claim 1, wherein an axis of rotating the first
substrate is parallel within 5.degree. to an axis of revolving the
processing aperture.
20. The method of claim 1, wherein obtaining the correction factor
and determining at least one of the first rotation angle or the
first revolution angle are performed by a controller.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation Application to U.S. patent
application Ser. No. 12/651,172, filed Dec. 31, 2009, which is
herein incorporated by reference for all purposes. This application
is related to U.S. patent application Ser. No. 12/027,980, filed
Feb. 7, 2008, and entitled "Combinatorial Process System," U.S.
patent application Ser. No. 12/028,643, filed Feb. 8, 2008, and
entitled "Combinatorial Process System," and U.S. patent
application Ser. No. 12/205,544, filed Sep. 5, 2008, and entitled
"Combinatorial Process System," all of which are herein
incorporated by reference for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates generally to semiconductor
processing tools. More specifically, a processing chamber including
a correction for a deposition location is described.
BACKGROUND OF THE INVENTION
[0003] Deposition processes are commonly used in semiconductor
manufacturing to deposit a layer of material onto a substrate.
Processing is also used to remove layers, defining features (e.g.,
etch), preparing layers (e.g., cleans), doping or other processes
that do not require the formation of a layer on the substrate.
Processes and process shall be used throughout the application to
refer to these and other possible known processes used for
semiconductor manufacturing and any references to a specific
process should be read in the context of these other possible
processes. In addition, similar processing techniques apply to the
manufacture of integrated circuits (IC) semiconductor devices, flat
panel displays, optoelectronics devices, data storage devices,
magneto electronic devices, magneto optic devices, packaged
devices, and the like. As feature sizes continue to shrink,
improvements, whether in materials, unit processes, or process
sequences, are continually being sought for the deposition
processes. However, semiconductor companies have traditionally
conducted research and development (R&D) on full wafer
processing through the use of split lots, as the deposition systems
are designed to support this processing scheme. This approach has
resulted in ever escalating R&D costs and the inability to
conduct extensive experimentation in a timely and cost effective
manner.
[0004] Techniques and systems for depositing increasing processing
throughput for semiconductor R&D have been previously
described. However, some of these systems are amenable to improved
accuracy during deposition to increase throughput. Thus, techniques
for improving the accuracy of the testing of multiple different
process variations on a single substrate is provided to more
efficiently evaluate the viability of different materials, unit
processes, or process sequences.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Various embodiments of the invention are disclosed in the
following detailed description and the accompanying drawings:
[0006] FIG. 1 is a simplified schematic diagram illustrating a
processing chamber configured to combinatorially process a
substrate disposed therein in accordance with one embodiment of the
invention;
[0007] FIG. 2 is a simplified schematic diagram of exemplary
different positions of the process kit shield relative to a
substrate in accordance with one embodiment of the invention;
[0008] FIG. 3 is a simplified schematic diagram illustrating a
pattern disposed over a substrate in accordance with one embodiment
of the invention;
[0009] FIG. 4 a simplified schematic diagram illustrating an
integrated high productivity combinatorial (HPC) system in
accordance with one embodiment of the invention;
[0010] FIG. 5 is an overhead view of a substrate showing a center
of the substrate, a revolution center of the process kit shield and
the processing aperture, and a position of the processing aperture
over the substrate;
[0011] FIG. 6 is an overhead view of the substrate after the
substrate has been rotated, showing the center of the substrate,
the revolution center, and the position of the processing
aperture;
[0012] FIG. 7 is an overhead view of the substrate after the
substrate pedestal has revolved;
[0013] FIG. 8 illustrates correction vectors on a substrate that
can be used to determine a correction factor according to various
embodiments described herein;
[0014] FIG. 9 illustrates a substrate processing using the
processing chamber after a rotation and a revolution;
[0015] FIG. 10 illustrates a case where the processing aperture is
offset from the desired position;
[0016] FIG. 11 illustrates a substrate that can be used to
determine a correction factor for the processing chamber;
[0017] FIG. 12 is a flowchart describing a process for determining
a correction factor for a semiconductor processing chamber;
[0018] FIG. 13 is a flowchart describing a process for processing
one or more regions of a substrate using a processing chamber and
correction factor as described herein; and
[0019] FIGS. 14A and 14B illustrate another technique for improving
alignment of a substrate relative to a substrate pedestal.
DETAILED DESCRIPTION
[0020] A detailed description of one or more embodiments is
provided below along with accompanying figures. The detailed
description is provided in connection with such embodiments, but is
not limited to any particular example. The scope is limited only by
the claims and numerous alternatives, modifications, and
equivalents are encompassed. Numerous specific details are set
forth in the following description in order to provide a thorough
understanding. These details are provided for the purpose of
example and the described techniques may be practiced according to
the claims without some or all of these specific details. For the
purpose of clarity, technical material that is known in the
technical fields related to the embodiments has not been described
in detail to avoid unnecessarily obscuring the description.
[0021] According to various embodiments, a combinatorial processing
chamber is described herein. The combinatorial processing chamber
can be used to process multiple regions of a substrate using
different processing parameters on different regions. For example,
one region can have one material deposited on it and another region
can have a different material deposited on it, although other
combinations and variations are possible. The combinatorial
processing chamber uses a rotating and revolving substrate pedestal
to be able to position a processing aperture relative to a
substrate and to be able to deposit on all locations or positions
on a substrate. The combinatorial processing chamber uses a
correction factor that accounts for variations in alignment and/or
configuration of the processing chamber so that the actual location
of deposition of a region is approximately the same as a desired
location of deposition.
I. Combinatorial Processing and a Combinatorial Processing
System
A. Combinatorial Processing
[0022] "Combinatorial Processing" generally refers to techniques of
differentially processing multiple regions of a substrate.
Combinatorial processing can be used to produce and evaluate
different materials, chemicals, processes, and techniques related
to semiconductor fabrication as well as build structures or
determine how the above coat, fill or interact with existing
structures. Combinatorial processing varies materials, unit
processes and/or process sequences across multiple regions on a
substrate.
[0023] As an example, a substrate (such as a wafer), can be
processed in a processing chamber that uses a plasma based process
such as physical vapor deposition (PVD) or plasma etching. The
substrate can be processed so that multiple regions of the
substrate are processed using different process parameters. For
example, one region can have a first material deposited thereon,
while another region has a different material deposited thereon to
examine the different properties of the materials. As another
example, the same material can be deposited on two different
regions using different unit processes or process sequences to
examine the effects of the differences in unit process or process
sequence. By depositing multiple regions having different
properties, many different process parameters can be tested or
examined in an accelerated manner.
B. Combinatorial Processing Chamber
[0024] FIG. 1 is a simplified schematic diagram illustrating a
processing chamber configured to combinatorially process a
substrate disposed therein in accordance with one embodiment of the
invention. Processing chamber 100 includes a bottom chamber portion
102 disposed under top chamber portion 116. Within bottom portion
102 substrate pedestal 106 is configured to hold a substrate 108
disposed thereon. Substrate pedestal 106 is capable of rotating
around a central axis 113 of the substrate pedestal 106. In one
embodiment, substrate pedestal 106 rotates approximately 185
degrees to provide full access to the surface of a substrate 108.
In another embodiment substrate pedestal 106 rotates 360 degrees.
In addition, substrate pedestal 106 may move in a vertical
direction or in a planar direction. It should be appreciated that
the rotation and movement in the vertical direction or planar
direction may be achieved through known drive mechanisms which
include magnetic drives, linear drives, worm screws, lead screws, a
differentially pumped rotary feed through drive, etc. In some
embodiments, the center of the substrate 108 may not align with the
center of the substrate pedestal 106 (i.e. the axis 113). The
correction factor can be used to account for this misalignment, as
well as other misalignments.
[0025] Substrate 108 may be a conventional round 200 millimeter,
300 millimeter or any other larger or smaller substrate/wafer size.
In other embodiments, substrate 108 may be a square, rectangular,
or other shaped substrate. One skilled in the art will appreciate
that substrate 108 may be a blanket substrate, a coupon (e.g.,
partial wafer), or even a patterned substrate having predefined
regions. In another embodiment, substrate 108 may have regions
defined through the processing described herein. The term region is
used herein to refer to a localized area on a substrate which is,
was, or is intended to be used for processing or formation of a
selected material. The region can include one region and/or a
series of regular or periodic regions pre-formed on the substrate.
The region may have any convenient shape, e.g., circular,
rectangular, elliptical, wedge-shaped, etc. In the semiconductor
field a region may be, for example, a test structure, single die,
multiple die, portion of a die, other defined portions of a
substrate, or undefined area of substrate, e.g. a blanket substrate
which is defined through the processing. Substrates can be any type
of substrate that can be processed by processing chamber 100, such
as semiconductor substrates for semiconductor devices, substrates
for creating solar, photovoltaic, or optoelectronic devices,
etc.
[0026] Top chamber portion 116 of chamber 100 in FIG. 1 includes
process kit shield 110, which defines a confinement region over a
radial portion of substrate 108. Process kit shield 110 is in
essence a sleeve having a base (optionally integral with the
shield) and an optional top within chamber 100 that may be used to
confine a plasma generated therein. The generated plasma will
dislodge particles from a target to process (e.g., be deposited) on
an exposed surface of substrate 108 to combinatorially process
regions of the substrate in one embodiment. In other embodiments,
other types of processing, such as plasma etching, can be performed
using the processing chamber 100. Process kit shield 110 is capable
of being moved in and out of chamber 100, i.e., the process kit
shield is a replaceable insert. Process kit shield 110 includes an
optional top portion, sidewalls and a base. In one embodiment,
process kit shield 110 is configured in a cylindrical shape,
however, the process kit shield may be any suitable shape and is
not limited to a cylindrical shape.
[0027] The process kit shield 110 is removable and replaceable.
When the process kit shield 110 is removed and/or replaced, the
calibration of the processing chamber 100 can be affected. If
coordinates are selected to deposit at a desired location (region)
on the substrate 108, the processing aperture 112 may deposit at an
actual location offset from the desired location because the
components of the processing chamber 100 may have a different
alignment than they did previously.
[0028] The base of process kit shield 110 includes a processing
aperture 112 that is configured to deposit at least one material on
the substrate. The processing aperture 112 can emit materials to be
deposited (e.g. sputtered) on the region of the substrate 108 over
which the processing aperture 112 is positioned. Within top portion
116 is cover plate 118 which is moveably disposed over the base of
process kit shield 110. Cover plate 118 (or aperture shutter) may
move across a bottom surface of the base of process kit shield 110
in order to cover or expose processing aperture 112 in one
embodiment. In another embodiment, cover plate 118 is controlled
through an arm extension which moves the cover plate to expose or
cover processing aperture 112 as will be described in more detail
below. It should be noted that although a single processing
aperture 112 is illustrated, multiple apertures may be included.
Each processing aperture 112 may be associated with a dedicated
cover plate or a cover plate can be configured to cover more than
one aperture simultaneously or separately. Alternatively,
processing aperture 112 may be a larger opening and plate 118 may
extend with that opening to either completely cover it or place one
or more fixed apertures within that opening for processing the
defined regions. In some embodiments, the processing aperture 112
may be rotatable to deposit non-circular patterns to match with the
shape of processed substrates. One or more quartz crystal
microbalance sensors can be mounted on the process kit to calibrate
the PVD film thickness and quality.
[0029] The optional top plate of process kit shield 110 of FIG. 1
may function as a datum shield as will be described further below.
Process heads 114 (also referred to as deposition guns) are
disposed within slots defined within the datum shield in accordance
with one embodiment of the invention. Where a datum shield is
utilized in the chamber, a datum shield slide cover plate 120 may
be included. Datum shield slide cover plate 120 (or gun shutter)
functions to seal off a deposition gun when the deposition gun may
not be used for the processing. For example, two deposition guns
114 are illustrated in FIG. 1. Process heads 114 are moveable in a
vertical direction so that one or both of the guns may be lifted
from the slots of the datum shield. While two process heads are
illustrated, any number of process heads may be included, e.g.,
three or four process heads may be included. Where more than one
process head is included, the plurality of process heads may be
referred to as a cluster of process heads. Slide cover plate 120
can be transitioned to isolate the lifted process heads 114 from
the processing area defined within process kit shield 110. In this
manner, the process heads are isolated from certain processes when
desired. It should be noted that while one slide cover plate 120 is
illustrated, multiple slide cover plates may be included so that
each slot or opening of the datum shield is associated with a cover
plate. Alternatively, slide cover plate 120 may be integrated with
the top of the shield unit 110 to cover the opening as the process
head is lifted or individual covers can be used for each
target.
[0030] Top section 116 of chamber 100 of FIG. 1 includes sidewalls
and a top plate which house process kit shield 110. Arm extensions
114a, which are fixed to process heads 114 extend through the
region defined within top portion 116. Arm extensions 114a may be
attached to a suitable drive, e.g., lead screw, worm gear, etc.,
configured to vertically move process heads 114 toward a top plate
of top portion 116. Arm extensions 114a may be pivotably affixed to
process heads 114 to enable the process heads to tilt relative to a
vertical axis. In one embodiment, process heads 114 tilt toward
processing aperture 112. In another embodiment, arm extensions 114a
are attached to a bellows that allows for the vertical movement and
tilting of process heads 114. Where a datum shield is utilized, the
openings are configured to accommodate the tilting of the process
heads. In one embodiment, the process heads are tilted by ten
degrees or less relative to the vertical axis. It should be
appreciated that the tilting of the process head enables tuning so
that the gun may be tilted toward an aperture in the base plate to
further enhance uniformity of a layer of material deposited through
the aperture.
[0031] As illustrated in FIG. 1, process kit shield 110 is moveable
in a vertical direction. The substrate pedestal 106 is configured
to revolve around an axis 111 and rotate about an axis 113. The
rotation and revolution of the substrate pedestal 106 allows for
the positioning of the processing aperture 112 over any location of
the substrate 108. The revolution of the substrate pedestal 106, in
particular, revolves the processing aperture 112 relative to the
substrate 108 (and relative to the substrate pedestal 106). As used
herein, revolution and revolving refer to positioning the
processing aperture 112 by rotating it about an axis 111 relative
to the substrate 108 and substrate pedestal 106. For example, in
other embodiments, the process kit shield 110 is configured and
able to revolve around the axis 111. It should be appreciated that
the axis 111 around which the substrate pedestal 106 revolves is
offset from both the axis 113 around which substrate pedestal 106
rotates and an axis 109 of a cluster of process heads in one
embodiment. In one embodiment, the axis 111 is approximately
parallel to the axis 113, for example, the axis 111 may be parallel
to within 5.degree. of the axis 113. In this manner, a plurality of
regions on substrate 108 may be exposed for combinatorial
processing as described further with reference to FIG. 3. While
process heads 114 are described as clustered on the same axis as
processing aperture 112, additional heads may be offset from the
cluster of heads for doping, implantation or deposition of small
amounts of a material, e.g., 1-10% without limitation. An
alternative embodiment to provide access to regions on the entire
substrate may include linear movement of upper chamber 116 as
opposed to movement in an arc as shown in the figures.
[0032] FIG. 2 is a simplified schematic diagram of exemplary
different positions of the process kit shield 110 in accordance
with one embodiment of the invention. Process kit shield 110 and
the processing aperture 112 may move relative to the substrate 108.
As discussed herein, substrate pedestal 106 may revolve about the
axis 111 to move the process kit shield 110 between positions 110-1
and 110-2 relative to the substrate pedestal 106. It should be
appreciated that top section 116 may be any suitable shape to
accommodate this movement, including circular, kidney shaped, oval,
rectangular, etc. In addition, the relative size of the process kit
shield 110 may be based on the number of heads and other design
factors. Thus, the process kit shield 110 may be smaller, larger,
or the same size as substrate 108 depending on the number and
configuration of process heads as well as other design factors.
FIGS. 5-7 illustrate the positioning of the processing aperture 112
above the substrate 108 during the rotation of the substrate 108
and the revolution of the processing aperture 112.
[0033] In some embodiments described herein, a controller
controlling the rotation of the substrate pedestal 106 and the
revolution of the process kit shield 110 can apply a correction
factor to account for offsets due to misalignments in the
processing chamber 100. The correction factor can be applied so
that the actual location of deposition on the substrate 108 is
approximately the same as the desired location of deposition on the
substrate.
[0034] FIG. 3 is a simplified schematic diagram illustrating a
pattern disposed over a substrate in accordance with one embodiment
of the invention. In FIG. 3, an array of regions 180 (i.e. multiple
regions 180) are processed on substrate 108. In order to provide
access to those regions for processing, between processing steps
and per the experimental design processing aperture 112 is moved
across a surface of substrate 108 within the slot in the base plate
and the substrate 108 is rotated and the processing aperture 112 is
revolved relative to the substrate 108 as necessary so that
multiple regions can be processed combinatorially on one substrate.
For example, as used herein, the substrate pedestal 106 (and the
substrate 108) are rotated through an angle .theta., and the
substrate pedestal 106 is revolved through an angle .omega. so that
the processing aperture 112 revolves relative to a center of the
substrate 108.
[0035] FIG. 4 a simplified schematic diagram illustrating an
integrated high productivity combinatorial (HPC) system in
accordance with one embodiment of the invention. HPC system
includes a frame 400 supporting a plurality of processing modules.
It should be appreciated that frame 400 may be a unitary frame in
accordance with one embodiment. In one embodiment, the environment
within frame 400 is controlled. Load lock/factory interface 402
provides access into the plurality of modules of the HPC system.
Robot 414 provides for the movement of substrates (and masks)
between the modules and for the movement into and out of the load
lock 402. Modules 404-412 may be any set of modules and preferably
include one or more combinatorial modules. For example, module 404
may be an orientation/degassing module, module 406 may be a clean
module, either plasma or non-plasma based, module 408 and 410 may
be combinatorial modules (e.g. the processing chamber 100) in
according with this invention or of other design, and module 412
may provide conventional clean or out-gassing as necessary for the
experiment design.
[0036] Any type of chamber or combination of chambers may be
implemented and the description herein is merely illustrative of
one possible combination and not meant to limit the potential
chamber or processes that can be supported to combine combinatorial
processing or combinatorial plus conventional processing of a
substrate/wafer. In one embodiment, a centralized controller 411,
may control the processes of the HPC system. In some embodiments,
the system includes multiple controllers. For example, each module
404-412 may have its own controller, and the robot 414 and
interface 402 may have their own controllers. As used herein, the
controller 411 can represent any combination of controllers, such
as a single controller that operates the entire system, multiple
controllers that operate each module individually, multiple
controllers that each operate multiple modules, etc. Further
details of one possible HPC system are described in U.S.
application Ser. Nos. 11/672,478 and 11/672,473. With HPC system, a
plurality of methods may be employed to deposit material upon a
substrate employing combinatoric processes.
II. Determination of Correction Factor
A. Substrate Layout and Positioning of Processing Aperture Relative
to the Substrate
[0037] FIG. 5 is an overhead view of a substrate 108 showing a
center 502 of the substrate 108, a revolution center 504 (of the
substrate pedestal 106 and the processing aperture 112 relative to
the substrate pedestal 106, along the axis 111), and a position 506
of the processing aperture 112. The position 506 of the processing
aperture 112 represents the position of the processing aperture 112
above the substrate 108, for example as is shown in FIG. 1. The
circle designating the position 506 of the processing aperture 112
denotes an approximate location of a region (e.g. one of the
regions 180) on the substrate 108 that is processed by the
processing chamber 100.
[0038] The layout of the substrate 108 as shown in FIG. 5, as well
as in FIGS. 6 and 7, is an ideal representation of the positions of
the centers 502 and 504 and position 506 of the processing aperture
112. In other words, FIG. 5 illustrates the desired positions of
the revolution center 504 and the desired center position 506 of
the processing aperture 112 when the system is in a "home" position
(i.e. (0, 0)) or when the processing aperture 112 is centered over
the center 502 of the substrate 108. In reality, the centers 502
and 504 and position 506 often do not align into their desired
positions because of the alignment of the individual components of
the processing chamber 100, including the position of the substrate
pedestal 106, the process kit shield 110, and the position of the
substrate 108 relative to the substrate pedestal 106, varies from
the ideal by some amount. In embodiments described herein, the
controller 411 is configured to use a correction factor that
accounts for the difference between the actual positions of the
centers and the desired positions of the centers, as well as the
difference between the location of the center of the substrate
pedestal 106 (i.e. the axis 113) and the center 502 of the
substrate 108. The description accompanying FIGS. 8-12 describes
how the correction factor is calculated. The description
accompanying FIG. 13 describes how deposition using the correction
factor is performed.
[0039] As used herein, the "desired" location of deposition on the
substrate 108 refers to a user's or system's (e.g. the controller
411) input, such as coordinates, describing where to deposit a
region on the substrate. The "actual" location of deposition on the
substrate 108 refers to the actual location that the deposition
occurs at in response to the input, and may differ from the desired
location because of misalignments in the processing chamber or
other reasons. However, using the correction factor, the actual
location can be approximately the same as the desired position. For
example, a user or a system may interact with the processing
chamber 100 by indicating the coordinates on the substrate that a
region should be deposited. The coordinates can be, for example,
Cartesian coordinates expressed in an (x, y) format. The controller
411 converts the coordinates to .theta. and .omega. angles (see
FIGS. 6 and 7) that can be used to rotate and revolve the substrate
pedestal 106. The controller 411 can also include the correction
factor in the conversion to .theta. and .omega. angles to ensure
that the actual and desired locations are approximately the
same.
[0040] FIG. 6 is an overhead view of the substrate 108 after the
substrate 108 has been rotated. As is described above, the
substrate 108 can be rotated by the substrate pedestal 106 about
the axis 113 to change the position of the revolution center 504
(e.g. from the position 504-1 to the position 504-2) so that other
areas of the substrate 108 can be accessible to the processing
aperture 112 by revolving the substrate 108 using the substrate
pedestal 106. As used herein, when the substrate 108 rotates by
rotation of the substrate pedestal 106, the rotation is through an
angle .theta.. As shown in FIG. 6, the processing aperture 112 is
still located at position 506 over the center 502 of the substrate
108 because the substrate pedestal 106 has not revolved to move the
processing aperture 112 relative to the substrate 108. The
processing aperture 112 shown here has a circular shape, however it
is understood that the processing aperture 112 can have any shape,
for example rectangular, triangular, etc. If the processing
aperture 112 is not circular, then upon rotation of the substrate
pedestal 106, the processing aperture 112 may reorient relative to
the substrate 108.
[0041] FIG. 7 is an overhead view of the substrate 108 after the
substrate pedestal 106 has revolved. The substrate pedestal 106
revolves around the axis 111 (i.e. the revolution center 504) and
through an angle .omega. to revolve the processing aperture 112
relative to the substrate 108. The processing aperture 112 (shown
as the position 506) is now positioned over the desired location of
the substrate 108 for deposition. The processing aperture 112 is
positioned over the desired location because the positions as shown
in FIG. 7 represent an ideal representation, where there is no
misalignment and no need for correction. For example, the aperture
112 can be used to deposit at least one material on a region 180 of
the substrate 108 corresponding to the position 506 of the
processing aperture 112. The region can be one of multiple regions
180 that are deposited in a combinatorial manner.
[0042] Using the rotation of the substrate 108 through the angle
.theta. and revolution of the substrate pedestal 106 through the
angle .omega., any location on the substrate 108 can be processed.
Generally, a user of the processing chamber 100 can instruct the
controller 411 to select a location on the substrate 108 to deposit
a material in a region or to perform any other processing operation
(e.g. etching). The location can be specified by giving
coordinates, for example Cartesian coordinates (e.g. in an (x, y)
format) or polar coordinates (e.g. specifying a distance and an
angle in a (r, .phi.)) format, or specifying the coordinates in the
rotation of the substrate 108 and the revolution of the processing
aperture 112 (.theta., .omega.) relative to the substrate pedestal
106. The coordinates can have a correction factor applied to them
such that the intended or desired location of the substrate 108 is
actually processed. The description of FIGS. 8-13 can be used to
determine or calculate and apply the correction factor.
B. Offsets and Correction Vectors
[0043] FIG. 8 illustrates the correction vectors on a substrate 108
that can be used to determine a correction factor according to
various embodiments described herein. The correction factor
described herein accounts for offsets between the actual positions
and the desired positions of certain features. As used herein, the
correction factor accounts for three offsets: a first offset
between the rotation center of the substrate pedestal and the
center of the substrate, a second offset between an actual position
of the aperture and a desired position of the aperture, and a third
offset between an actual position of the revolution center and a
desired position of the revolution center.
[0044] Correction vectors are used to calculate the correction
factor, and are defined as vectors originating at the origin of the
frame of reference. The correction vectors measure the actual
position of the features relative to the frame of reference, and
using the calculations described herein can be used to calculate a
correction factor that accounts for the three offsets described
above. As described herein, the frame of reference is defined by
the rotation center 802 of the substrate pedestal 106 along the
axis 113, which is (0, 0). The line 810 defines 0.degree. in polar
coordinates, with the angle .phi. increasing in the
counterclockwise direction. Additionally, a Cartesian coordinate
system can be defined by the axes 812, with the origin (0, 0) at
the rotation center 802.
[0045] There are three correction vectors 804, 806, and 808 that
can be used to determine the correction factor:
[0046] Correction vector 804, which defines the location of the
revolution center 504, which is given by (r.sub.r, .phi..sub.r) in
polar coordinates,
[0047] Correction vector 806, which defines the position of the
center 810 of the position 506 of the processing aperture 112,
which is given by (r.sub.a, .phi..sub.a) in polar coordinates,
and
[0048] Correction vector 808, which defines the offset between the
center 502 of the substrate 108 and the rotation center 802, which
is given by (x.sub.w, y.sub.w) in Cartesian coordinates.
[0049] FIG. 9 illustrates a substrate 108 processing using the
processing chamber 100 after a rotation and a revolution. The
substrate 108 shown in FIG. 9 illustrates the ideal situation:
where the input of desired coordinates into the processing chamber
100 results in the processing aperture 112 being positioned to
process an actual location that is the same as the desired location
that is intended by the user. Therefore, the position of the
substrate center 502, the revolution center 504, and the position
506 of the aperture do not deviate from their ideal or desired
positions.
[0050] The substrate 108 has completed a rotation of the substrate
pedestal 106 and a revolution of the substrate pedestal 106. The
processing aperture 112 begins at the home position (0, 0), as is
indicated by the dashed circle showing the starting position 506-1
of the processing aperture 112, and after a rotation and
revolution, the processing aperture 112 is located at the desired
position at vector 902 (r.sub.1, .phi..sub.1), as indicated by the
solid circle showing the final position 506-2 of the processing
aperture 112. The revolution center 504 is initially located at the
position 504-1 of the revolution center, and after a rotation
through the angle .theta., the revolution center 504 moves to the
position 504-2. The substrate pedestal 106 is then revolved through
the angle .omega. about the revolution center 504 at the position
504-2 so that the processing aperture 112 moves to the position
506-2. The vector (r.sub.1, .phi..sub.1) defines the position 506
of the processing aperture 112 above the substrate 108 after a
rotation and a revolution.
[0051] Representative equations for r.sub.1 and .phi..sub.1 can be
determined using trigonometry:
r 1 = 2 r r sin ( .omega. 2 ) ##EQU00001## .PHI. 1 = .theta. +
.PHI. r + ( .pi. - .omega. 2 ) ##EQU00001.2##
[0052] FIG. 10 illustrates a case where there is a processing
aperture correction vector (i.e. the processing aperture 112 is
offset from the desired position). The processing chamber 100 has
been rotated and revolved so that the processing aperture 112 is at
a position over the wafer at the vector 902 (r.sub.1, .phi..sub.1).
However, the processing aperture 112, at the home position, was
offset from the center 502 of the substrate 108 by the vector 806
(r.sub.a, .phi..sub.a) before the rotation and revolution. The
vector 1002 is the vector 806 located at the end of the vector 902
and has the value (r.sub.a, .phi..sub.2), where
.phi..sub.2=.phi..sub.a+.theta.-.omega.. The final position of the
aperture (i.e. the "actual" position) is the vector sum of the
vectors 902 (r.sub.1, .phi..sub.1) and 1002 (r.sub.a, .phi..sub.2),
minus the vector 808 (x.sub.w, y.sub.w), such that in Cartesian
coordinates, the correction factor can be given by F(.theta.,
.omega.)=(x.sub.f, y.sub.f), where x.sub.f and y.sub.f are given
by:
x.sub.f=r.sub.1 cos .phi..sub.1+r.sub.a cos .phi..sub.2-x.sub.w and
(Equation 1)
y.sub.f=r.sub.1 sin .phi..sub.1+r.sub.a sin .phi..sub.2-y.sub.w
(Equation 2)
C. Measurement of Correction Vectors
[0053] For a specific configuration of a processing chamber 100,
the correction vectors can be measured by processing predetermined
regions of a substrate, measuring their actual locations, comparing
the actual locations to the desired locations of the processed
regions, and using the location on the test substrate to process
any other substrates using the specific configuration. Changes in
the processing chamber 100 may require recalculating the correction
vectors and the correction factor. For example, if the process kit
shield 110 or the substrate pedestal 106 are removed and
reinstalled, the correction factor may change and may need to be
recalculated.
[0054] FIG. 11 illustrates a substrate 1100 processed to determine
a correction factor for the processing chamber 100. Six regions
1102-1108 of the substrate 1100 are processed, each at locations on
the substrate 1100 that can be used to calculate the correction
vectors. Table 1 lists each of the regions, the region's desired
location in units of rotation degrees (0) and revolution degrees
(.omega.). Table 1 also lists example actual x and y coordinates of
the deposited regions for an example of the substrate 1100 (it is
understood, however, that these coordinates are representative of
one specific system configuration, which is an example of
measurements taken in one processing system, and that different
systems will likely have different actual measurements). The x and
y coordinates are listed in the frame of reference where the center
of the substrate 108 is (0, 0), and the axes are x-axis 1114 and
y-axis 1116.
TABLE-US-00001 Region Rotation (.theta.) Revolution (.omega.) X
Coords (mm) Y Coords (mm) 1102 20 90 -55.86 85.83 1104 0 90 -23.03
99.41 1106 0 -90 99.33 21.83 1108 180 -90 -100.81 -22.96 1110 0 0
5.39 -3.13 1112 180 90 21.64 -100.80
[0055] The regions 1102-1112 specified by the rotation and
revolution coordinates as shown here can be used to determine the
correction factor, however, it is understood that other groups of
regions in different locations can also be used. These regions
allow for the isolation of the correction vectors and errors:
[0056] The rotation center is halfway between regions 1102 and
1112, or halfway between regions 1106 and 1108. Though the
individual regions 1102, 1112, 1106, and 1108 are affected by the
offsets vectors 804 and 806, the center point between the regions
is not.
[0057] The revolution center is halfway between regions 1104 and
1106, or position of the revolution center on the substrate when
rotated by 180.degree. is the halfway point between regions 1108
and 1112.
[0058] The aperture center correction vector can be determined from
the center of the region 1110. It can be reconfirmed by using the
rotation and revolution centers to calculate the desired position
of the region 1104, and then calculating the vector between the
desired position of region 1104 and the actual position of the
region 1104.
[0059] The region 1102 is used to reconfirm sign conventions and
identify the regions 1104-1112 in the case of gross (e.g.
>45.degree.) offsets.
[0060] In this example, more regions than are necessary are
processed; the additional regions can be used to confirm the
accuracy of the calculated values. For example, although the
regions 1104 and 1106 can be used to calculate the correction
vector for the revolution center, the regions 1106 and 1108 can be
used to confirm the location of the revolution center.
[0061] FIG. 12 is a flowchart describing a process 1200 for
determining a correction factor for a semiconductor processing
chamber. In operation 1202, multiple regions of the substrate 1100
are processed. The multiple regions are processed using a
processing aperture (e.g. the processing aperture 112) and at least
one of a rotation of a substrate pedestal holding the substrate
(e.g. the rotation through the angle .theta. of the substrate
pedestal 106) about an axis of the substrate pedestal (e.g. the
axis 113) and a revolution of the processing aperture about another
axis (e.g. the axis 111). The processing aperture 112 is, in some
embodiments, revolved relative to the substrate 108 when the
substrate pedestal 106 is revolved through the angle .omega.. The
axes are approximately parallel to each other (e.g. within
5.degree. of each other), and the rotation and the revolution are
to position the process aperture over the multiple regions of the
substrate to be processed.
[0062] In operation 1204, the actual positions of the multiple
regions are measured. In operation 1206, the actual positions are
compared to the desired positions, and in operation 1208,
correction vectors are calculated based on the comparison. The
correction factor can then be determined using the correction
vectors.
[0063] For example, in operation 1202, the regions 1102-1112 can be
processed, and the actual positions of those regions are measured
in operation 1204, for example by taking a photo of the substrate
1100 and determining the locations (i.e. the actual positions) of
the regions 1102-1112. The rotation center can then be determined,
for example, using the example in Table 1, the rotation center is
located at (-0.72 mm, -0.63 mm) in Cartesian coordinates.
[0064] If the calculations are adjusted to make the rotation center
(0, 0), then the revolution center 504 can then be given calculated
as (r.sub.r, .phi..sub.r)=(72.54 mm, 57.6.degree.), the position of
the aperture 506 can be give as (r.sub.a, .phi..sub.a)=(0.11 mm,
223.8.degree.), the position of the substrate center is given as
(x.sub.w, y.sub.w)=(0.72 mm, 0.63 mm). Using these numbers and
Equations 1 and 2, the correction factor can be applied for any
given desired location so that the actual location of deposition
will be approximately the desired location.
D. Calculation of Rotation and Revolution Angles for Desired
Location
[0065] In order to have the actual location of deposition be
approximately the same as the desired location of deposition, the
angles .theta. for the rotation of the substrate pedestal 106 and
.omega. for the revolution of the substrate pedestal 106 can be
determined for a desired location on the substrate by solving for
.theta. and .omega. in the equation (.theta.,
.omega.)=F.sup.-1(x.sub.f, y.sub.f) (recalling above that
F(.theta., .omega.)=(x.sub.f, y.sub.f)). One way to approximate the
values for .theta. and .omega. is using an iterative
two-dimensional Newton's method:
f 1 = r 1 cos .PHI. 1 + r a cos .PHI. 2 - x w - x f = 0 ( Equation
3 ) f 2 = r 1 sin .PHI. 1 + r a sin .PHI. 2 - y w - y f = 0 (
Equation 4 ) J ( .theta. , .omega. ) = ( .differential. f 1
.differential. .theta. .differential. f 1 .differential. .omega.
.differential. f 2 .differential. .theta. .differential. f 2
.differential. .omega. ) ( Equation 5 ) ##EQU00002##
[0066] Equations 3-5 can be calculated out in the following
manner:
.differential. f 1 .differential. .theta. = - r 1 sin .PHI. 1 - r a
sin .PHI. 2 ##EQU00003## .differential. f 1 .differential. .omega.
= r 1 2 sin .PHI. 1 + r r cos .omega. 2 cos .PHI. 1 + r a sin .PHI.
2 ##EQU00003.2## .differential. f 2 .differential. .theta. = r 1
cos .PHI. 1 + r a cos .PHI. 2 ##EQU00003.3## .differential. f 2
.differential. .omega. = - r 1 2 cos .PHI. 1 + r r cos .omega. 2
sin .PHI. 1 - r a cos .PHI. 2 ##EQU00003.4##
[0067] Beginning with an initial estimate of the uncorrected
coordinates (.theta..sub.0, .omega..sub.0), an iteration can be
performed to give:
(.theta..sub.k+1, .omega..sub.k+1)=(.theta..sub.k,
.omega..sub.k)-J.sup.-1(.theta..sub.k,
.omega..sub.k)F(.theta..sub.k, .omega..sub.k)
[0068] For example, using the correction vectors calculated above,
(.theta..sub.0, .omega..sub.0) where the (x, y) position on the
substrate is (2 in, 2 in) is equal to (.theta..sub.0,
.omega..sub.0)=(4.418, 0.982).
III. Deposition Using Correction Factor
[0069] FIG. 13 is a flowchart describing a process 1300 for
processing one or more regions of a substrate using a processing
chamber and correction factor as described herein. The process 1300
begins in operation 1302, where a correction factor is obtained.
The correction factor can be obtained using the process 1200, for
example.
[0070] In operation 1304, a substrate is loaded onto the substrate
pedestal 106. The substrate can be loaded using a robot 414, for
example. In operation 1306, the controller 411 determines the
rotation and revolution angles .theta. and .omega. using the
correction factor and the coordinates inputted for the desired
location on the substrate 108. The chamber 100 then rotates the
substrate pedestal 106 about the axis 111 according to the request
to deposit at a desired location in operation 1308. In operation
1310 the chamber 100 revolves the processing aperture 112 (e.g. by
revolving the substrate pedestal 106) about the axis 113 according
to the request. The rotating and revolving use the correction
factor obtained in operation 1302.
[0071] In operation 1312, the region is processed, for example by
depositing a material using PVD. In operation 1314, it is
determined whether any additional regions are to be processed.
Additional regions of the substrate can be processed using
different processing characteristics (i.e. using different
processing parameters such as different materials, different
deposition times, different temperatures, different pressures,
etc.) so that a combinatorial comparison can be made. For example,
a first region can be processed by depositing a first material, and
a second region can be processed using a different material.
Additional variables that can be evaluated in a combinatorial
fashion include power, gas mixtures, target compositions, etc. If
additional regions are to be processed, the process 1300 returns to
operation 1306. If no additional regions are to be processed, the
process 1300 finishes.
IV. Other Alignment Techniques
[0072] FIGS. 14A and 14B illustrate another technique for improving
alignment of a substrate 108 relative to a substrate pedestal 106.
FIG. 14A shows a cross-sectional view of the substrate pedestal 106
and the substrate 108, and FIG. 14B shows an overhead view of the
substrate pedestal 106 and the substrate 108. The chamber 100
includes a movable substrate pedestal 106 that can move 1402 to
change the relationship of the substrate 108 to the processing
aperture 112. In other embodiments, the substrate 108 is movable
with respect to the substrate pedestal 106; in other words, if the
substrate 108 is misaligned upon the substrate pedestal 106, the
substrate 108 can be move either manually or using a robot 414 or
other mechanism.
[0073] An imaging device 1404 (e.g. a camera) is located in a
position relative to the processing aperture 112 so that the
imaging device 1404 can capture an image through the processing
aperture 112. The imaging device 1404 can be, for example, directly
above the processing aperture 112 so that a feature 1406 on the
substrate 108 is visible through the processing aperture 112. The
feature 1406 may be, for example, a processed region (e.g. a
deposited region or an etched region), some other kind of marking,
a wafer notch, etc. In one embodiment, the feature 1406 is sized so
that the imaging device 1404 views the feature 1406 as
approximately occupying the entirety of the processing aperture
112. For example, if the process kit shield 110 is very close to
the substrate 108, the feature 1406 can have approximately the same
shape and size as the processing aperture 112.
[0074] Once an image of the feature 1406 is created, the controller
411 can determine whether the alignment of the substrate is
correct. If the alignment is correct, the substrate 108 can be
processed by rotating and revolving the substrate pedestal 106 as
described above to position the processing aperture 112 above a
region of the substrate 108 for processing. If the alignment is not
correct, the substrate 108 can then be moved; either relative to
the processing aperture 112 or relative to both the processing
aperture 112 and the substrate pedestal 106. The controller 411 can
calculate the amount of movement necessary, and can use the imaging
device 1404 to confirm that the alignment is correct after the
movement.
[0075] Although the foregoing examples have been described in some
detail for purposes of clarity of understanding, the invention is
not limited to the details provided. There are many alternative
ways of implementing the invention. The disclosed examples are
illustrative and not restrictive.
* * * * *