U.S. patent application number 15/950113 was filed with the patent office on 2018-08-09 for distributed, non-concentric multi-zone plasma source systems, methods and apparatus.
The applicant listed for this patent is Lam Research Corporation. Invention is credited to Souheil Benzerrouk, Andrew Cowe, William Entley, Richard Gottscho, Siddharth P. Nagarkatti, Ali Shajii.
Application Number | 20180228015 15/950113 |
Document ID | / |
Family ID | 48430158 |
Filed Date | 2018-08-09 |
United States Patent
Application |
20180228015 |
Kind Code |
A1 |
Shajii; Ali ; et
al. |
August 9, 2018 |
Distributed, Non-Concentric Multi-Zone Plasma Source Systems,
Methods and Apparatus
Abstract
A chamber top for a processing chamber is provided. The chamber
top includes a first plasma source oriented horizontally over the
chamber top and a second plasma source oriented horizontally over
the chamber top. The second plasma source is arranged
concentrically around the first plasma source. Also included is a
first plurality of ferrites encircling the first plasma source and
a second plurality of ferrites encircling the second plasma source.
A first primary winding is disposed around an outer circumference
of the first plasma source and a second primary winding disposed
around an outer circumference of the second plasma source. The
first and second primary windings pass through the respective
plurality of ferrites. A plurality of outlets is disposed on a
lower portion of the first and second plasma sources, and the
plurality of outlets is oriented between adjacent ones of the first
and second plurality of ferrites. The plurality of outlets is
configured to connect the first and second plasma sources of the
chamber top to the processing chamber.
Inventors: |
Shajii; Ali; (Weston,
MA) ; Gottscho; Richard; (Fremont, CA) ;
Benzerrouk; Souheil; (Hudson, NH) ; Cowe; Andrew;
(Andover, MA) ; Nagarkatti; Siddharth P.; (Acton,
MA) ; Entley; William; (Wakefield, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lam Research Corporation |
Fremont |
CA |
US |
|
|
Family ID: |
48430158 |
Appl. No.: |
15/950113 |
Filed: |
April 10, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13627696 |
Sep 26, 2012 |
9967965 |
|
|
15950113 |
|
|
|
|
61561167 |
Nov 17, 2011 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01J 37/32082 20130101;
H01J 37/32422 20130101; H01J 37/32669 20130101; H01J 37/32449
20130101; H01J 37/321 20130101; H01J 37/32816 20130101; H05H 1/50
20130101; H01J 37/3266 20130101; H01J 2237/334 20130101; H05H 1/46
20130101; H05H 2001/4682 20130101 |
International
Class: |
H05H 1/46 20060101
H05H001/46; H01J 37/32 20060101 H01J037/32; H05H 1/50 20060101
H05H001/50 |
Claims
1. A chamber top for a processing chamber, comprising, a first
plasma source oriented horizontally over the chamber top; a second
plasma source oriented horizontally over the chamber top, the
second plasma source is arranged concentrically around the first
plasma source; a first plurality of ferrites encircling the first
plasma source, and a second plurality of ferrites encircling the
second plasma source; a first primary winding disposed around an
outer circumference of the first plasma source and a second primary
winding disposed around an outer circumference of the second plasma
source, such that the first and second primary windings pass
through the respective plurality of ferrites; and a plurality of
outlets disposed on a lower portion of the first and second plasma
sources, the plurality of outlets being oriented between adjacent
ones of the first and second plurality of ferrites; wherein the
plurality of outlets is configured to connect the first and second
plasma sources of the chamber top to the processing chamber.
2. The chamber top of claim 1, wherein each of the first and second
plurality of ferrites are substantially evenly spaced apart with
respect to each other.
3. The chamber top of claim 1, wherein the first and second plasma
sources are ring shaped.
4. The chamber top of claim 1, wherein each of the plurality of
ferrites respectively encircle each of the plasma sources at
discrete cross-sections, and at each discrete cross-section a
respective ferrite includes a bottom region, side regions and a top
region.
5. The chamber top of claim 4, wherein the bottom region of each
ferrite is disposed adjacent to a bottom surface of a respective
one of the first and second plasma sources, the side regions of
each ferrite is disposed adjacent to side surfaces of said
respective one of the first and second plasma sources, the top
region of each ferrite is disposed adjacent to a top surface of
said respective one of the first and second plasma sources.
6. The chamber top of claim 1, wherein inlets in the chamber top
are aligned with the plurality of outlets to connect the first and
second plasma sources of the chamber top to the process
chamber.
7. The chamber top of claim 1, wherein each of the first and second
primary windings is coupled to a respective primary current source
controlled by a controller.
8. The chamber top of claim 1, wherein the chamber top is connected
to chamber walls of the processing chamber, the processing chamber
includes a substrate support that is disposed in the processing
chamber and below the chamber top.
9. The chamber top of claim 1, further comprising, a plurality of
process gas inlets connected to each of the first and second plasma
sources, the process gas inlets being interfaced with one or more
processing gases to form a plasma in the respective plasma
sources.
10. The chamber top of claim 1, wherein at least a portion of the
plurality outlets are coupled to a ground potential.
11. The chamber top of claim 1, wherein the first plasma source is
controlled independent of the second plasma source to provide
multi-zone plasma control for plasma directed into said processing
chamber.
12. A chamber top for a processing chamber, comprising, a first
ring chamber disposed over the chamber top; a second ring chamber
disposed over the chamber top, the second ring chamber is arranged
concentrically around the first ring chamber; a first plurality of
ferrites encircling the first ring chamber, and a second plurality
of ferrites encircling the second ring chamber; a first primary
winding disposed around an outer circumference of the first ring
chamber and a second primary winding disposed around an outer
circumference of the second ring chamber, such that the first and
second primary windings pass through the respective plurality of
ferrites; and a plurality of outlets disposed on a lower portion of
the first and second ring chambers, each of the plurality of
outlets is located in between adjacent ones of the first and second
plurality of ferrites; wherein the plurality of outlets is
configured to connect the first and second ring chambers of the
chamber top to the processing chamber.
13. The chamber top of claim 12, wherein the first ring chamber is
controlled independent of the second ring chamber to provide
multi-zone plasma control for plasma directed into said processing
chamber.
14. The chamber top of claim 12, wherein each of the first and
second plurality of ferrites are substantially evenly spaced apart
with respect to each other.
15. The chamber top of claim 12, wherein each of the plurality of
ferrites respectively encircle each of the ring chambers at
discrete cross-sections, and at each discrete cross-section a
respective ferrite includes a bottom region, side regions and a top
region.
16. The chamber top of claim 15, wherein the bottom region of each
ferrite is disposed adjacent to a bottom surface of a respective
one of the first and second ring chambers, the side regions of each
ferrite is disposed adjacent to side surfaces of said respective
one of the first and second ring chambers, the top region of each
ferrite is disposed adjacent to a top surface of said respective
one of the first and second ring chambers.
17. The chamber top of claim 12, wherein each of the first and
second primary windings is coupled to a respective primary current
source controlled by a controller.
18. The chamber top of claim 12, wherein the chamber top is
connected to chamber walls of the processing chamber, the
processing chamber includes a substrate support that is disposed in
the processing chamber and below the chamber top.
19. The chamber top of claim 12, further comprising, a plurality of
process gas inlets connected to each of the first and second ring
chambers, the process gas inlets being interfaced with one or more
processing gases to form a plasma in the respective ring
chambers.
20. The chamber top of claim 12, wherein at least a portion of the
plurality outlets are coupled to a ground potential.
Description
PRIORITY CLAIM
[0001] This application claims priority from U.S. patent
application Ser. No. 13/627,696, filed on Sep. 26, 2012, and
entitled "Distributed, Non-Concentric Multi-Zone Plasma Source
Systems, Methods and Apparatus," which claims priority to U.S.
Provisional Patent Application No. 61/561,167, filed on Nov. 17,
2011 and entitled "Distributed Multi-Zone Plasma Source Systems,
Methods and Apparatus" all of which are incorporated herein by
reference in their entirety.
RELATED APPLICATIONS
[0002] This application is related to the following applications:
U.S. patent application Ser. No. 12/852,352, filed on Aug. 6, 2010
(U.S. Pat. No. 9,155,181, issued on Oct. 6, 2015), and entitled
"Distributed Multi-Zone Plasma Source Systems, Methods and
Apparatus," U.S. patent application Ser. No. 12/852,364, filed on
Aug. 6, 2010 (U.S. Pat. No. 8,999,104, issued on Apr. 7, 2015), and
entitled "Systems, Methods and Apparatus for Separate Plasma Source
Control," and U.S. patent application Ser. No. 12/852,375, filed on
Aug. 6, 2010 (U.S. Pat. No. 9,449,793, issued on Sep. 20, 2016),
and entitled "Systems, Methods and Apparatus for Choked Flow
Element Extraction," all of which are incorporated herein by
reference in their entirety.
BACKGROUND
[0003] The present invention relates generally to plasma reaction
chambers, and more particularly, to methods, systems and apparatus
for plasma reaction chambers separate from the wafer processing
chamber.
[0004] FIG. 1A is a side view of a typical parallel-plate,
capacitive, plasma processing chamber 100. FIG. 1B is a top view of
a substrate 102 processed in the typical parallel-plate,
capacitive, plasma processing chamber 100. The typical plasma
processes processing chamber 100 includes a top electrode 104, a
substrate support 106 for supporting a substrate to be processed
102. The substrate support 106 can also be a bottom electrode. The
top electrode 104 is typically a showerhead type electrode with
multiple inlet ports 109. The multiple inlet ports 109 allow
process gases 110 in across the width of the processing chamber
100.
[0005] The typical parallel-plate, capacitive plasma reactor 100 is
used for processing round planar substrates. Common processes are
dielectric etch and other etch processes. Such plasma reactors
typically suffer from inherent center-to-edge non-uniformities of
neutral species.
[0006] Although these systems work well, some produce
center-to-edge non-uniformities of neutral species which arise from
the differences in one or more of a flow velocity, an effective gas
residence time, and one or more gas chemistries present at the
center of the substrate as compared to the flow velocity, effective
gas residence time, and one or more gas chemistries present at the
edge. The one or more gas chemistries can be caused by gas-phase
dissociation, exchange and recombination reactions.
[0007] By way of example, as the process gases are introduced
across the width of the processing chamber the plasma 112 is formed
between the top electrode 104 and bottom electrode 106 and the
plasma is formed. Plasma byproducts 118 are formed by the reaction
of radicals and neutrals in the plasma 112 with the surface of the
substrate 102. The plasma byproducts 118 are drawn off to the sides
of the substrate and into pumps 108. Plasma byproducts can include
one or more dissociation reactions (e.g.,
CF4+e.sup.-.fwdarw.CF3+F+e.sup.-) and/or one or more ionizations
(e.g., CF4+e.sup.-.fwdarw.CF3.sup.++F) and/or one or more
excitations (e.g., Ar.fwdarw.Ar.sup.++e.sup.-) and/or one or more
attachments (e.g., CF4+e.sup.-.fwdarw.CF3+F.sup.-) and/or one or
more binary reactions (e.g., CF3+H.fwdarw.CF2+HF).
[0008] Plasma byproducts 118 can also include etch byproducts
including the etchant, F, CFx, SiF2, SiF4, Co, CO2. Etch byproducts
can also dissociate in the plasma 112.
[0009] Recombination also occurs during the plasma processing.
Recombination produces recombination products 120. Recombination
typically occurs when the radicals and neutrals from the plasma 112
impact surfaces such as the bottom surface of the top electrode
104. The recombination products 120 are then drawn off the side of
the substrate 102 into pumps 108, similar to the plasma byproducts
118. Plasma recombination products 120 can include one or more wall
or surface reactions (e.g., F+CF.fwdarw.CF2, and/or H+H.fwdarw.H2,
and/or O+O.fwdarw.O2, and/or N+N.fwdarw.N2). Plasma recombination
products 120 can also include deposition where CFx forms a polymer
on the wall or other internal surface of the chamber 100.
[0010] It should be noted that as shown in FIG. 1A, the plasma
byproducts are drawn off one side of the substrate 102 and the
recombination products 120 are drawn off the opposite side of the
substrate 102 for clarity purposes only. In actual practice, those
skilled in the art would realize that both the recombination
products 120 and the plasma byproducts 118 are intermixed and drawn
off both sides of the substrate 102 to pumps 108 or other
means.
[0011] As the plasma processing occurs, concentrations of the
recombination products 120 and the plasma byproducts 118 vary from
the center to the edge of the substrate 102. As a result, the
concentrations of the process gases, radicals and neutral species
in the plasma 112 also correspondingly vary. Thus, the effective
plasma processing, etch in this instance, varies from the center to
the edge of the substrate 102. There are, however, a number of
chamber configurations and structures that can be implemented to
reduce or control the plasma.
[0012] With such controls, the plasma radicals and neutral species
are most concentrated at the center of the substrate 102 in plasma
processing regions 114A and 116A over central portion 102A of the
substrate 102. Further, the concentrations of the radicals and
neutral species are somewhat less concentrated in intermediate
plasma processing regions one 114B and 116B over intermediate
portion 102B of the substrate 102. Further still, the
concentrations of the radicals and neutral species are further
diluted and less concentrated in edge plasma processing regions
114C and 116C over the edge portion 102C of the substrate 102.
[0013] Thus, plasma processing occurs fastest in the center plasma
processing regions 114A and 116A over the center portion 102A of
substrate 102 as compared to the plasma processing that occurs
slightly slower in the intermediate plasma processing regions 114B
and 116B over the intermediate portion 102B of substrate 102 and
even slower in the plasma processing of the edge plasma processing
regions 114C and 116C over the edge portion 102C of the substrate.
This results in a center-to-edge nonuniformity of the substrate
102.
[0014] This center-to-edge nonuniformity is exacerbated in small
volume product plasma processing chambers that have a very large
aspect ratio. For example, a very large aspect ratio is defined as
when the width W of the substrate is about four or more or more
times the height H of the plasma processing region. The very large
aspect ratio of the plasma processing region further concentrates
the plasma byproducts 118 and recombination products 120 in the
plasma processing regions 114A-116C.
[0015] Although this center-to-edge non-uniformity of neutral
species is not the only cause of center-to-edge process uniformity,
in many dielectric etch applications it is a significant
contributor. Specifically, neutral-dependent processes such as gate
or bitline mask open, photoresist strip over low-k films, highly
selective contact/cell and via etch may be especially sensitive to
these effects. Similar problems may apply in other parallel-plate
plasma reactors, besides those used for wafer dielectric etch.
[0016] In view of the foregoing, there is a need for improving the
center-to-edge uniformity in plasma etch processes.
SUMMARY
[0017] Broadly speaking, the present invention fills these needs by
providing a distributed multi-zone plasma source. It should be
appreciated that the present invention can be implemented in
numerous ways, including as a process, an apparatus, a system,
computer readable media, or a device. Several inventive embodiments
of the present invention are described below.
[0018] In one embodiment, a chamber top for a processing chamber is
provided. The chamber top includes a first plasma source oriented
horizontally over the chamber top and a second plasma source
oriented horizontally over the chamber top. The second plasma
source is arranged concentrically around the first plasma source.
Also included are a first plurality of ferrites encircling the
first plasma source and a second plurality of ferrites encircling
the second plasma source. A first primary winding is disposed
around an outer circumference of the first plasma source and a
second primary winding disposed around an outer circumference of
the second plasma source. The first and second primary windings
pass through the respective plurality of ferrites. A plurality of
outlets is disposed on a lower portion of the first and second
plasma sources, and the plurality of outlets is oriented between
adjacent ones of the first and second plurality of ferrites. The
plurality of outlets is configured to connect the first and second
plasma sources of the chamber top to the processing chamber.
[0019] One embodiment provides a processing chamber including
multiple plasma sources in a process chamber top. Each one of the
plasma sources is a ring plasma source including a primary winding
and multiple ferrites.
[0020] Multiple plasma chamber outlets can couple a plasma chamber
of each one of the plasma sources to the process chamber. The
plasma sources can be arranged in at least one of a rectangular
array, a linear array, or a non-concentric circular array. The
processing chamber can also include at least one process gas inlet
coupling a process gas source to each one of the plasma
sources.
[0021] The multiple ferrites can be substantially evenly
distributed around the circumference of each of the plasma sources.
Each one of the plasma sources can be one of a group of shapes
consisting of substantially round, substantially triangular,
substantially rectangular, or substantially polygonal shape.
[0022] Each of the plasma source can have a substantially same
shape or different shapes. Each of the plasma sources can have a
substantially same size or different sizes. Each the plasma sources
are separated from the remaining plasma sources by a separation
distance. The respective separation distances can be substantially
equal separation distance. Alternatively, the respective separation
distances can be substantially different separation distances. Each
one of the plasma sources can be coupled to a controller and a
primary current source.
[0023] Another embodiment provides a method of generating a plasma
including delivering a process gas into a selected one multiple
plasma sources, applying a primary current to a respective primary
winding around the exterior of the selected plasma source,
generating magnetic field in the primary winding, concentrating the
magnetic field with multiple ferrites in the selected plasma
source, inducing a secondary current in the process gas in a plasma
chamber in selected the plasma source and generating a plasma in
the process gas in the plasma chamber in the selected plasma source
with the secondary current.
[0024] The method can also include delivering at least one of a
neutral species and a radical species to a process chamber through
multiple outlet ports. The multiple outlet ports couple the plasma
chamber to a process chamber. The method can also include removing
at least one of a plasma byproduct and a recombination product from
the process chamber through multiple outlets in a process chamber
top. At least one of the outlets is located in a substantially
central location in the process chamber top. The ferrites can be
substantially evenly distributed around the circumference of the
ring plasma chamber. The method can also include receiving a
process feedback signal from at least one process monitoring sensor
and adjusting at least one set point of at least one of the
multiple plasma sources. The method can also include moving at
least one of the multiple plasma sources relative to a substrate
support in the process chamber.
[0025] Another embodiment provides a plasma processing system
including multiple plasma sources mounted in a process chamber top.
Each one of the plasma sources including a ring plasma chamber, a
primary winding around an exterior of the ring plasma chamber and
multiple ferrites. The ring plasma chamber passes through each of
the ferrites. Multiple plasma chamber outlets couple each ring
plasma chamber to the process chamber. At least one process
monitoring sensor and a controller are included. The controller
including logic for delivering a process gas into the ring plasma
chamber, logic for applying a primary current to the primary
winding around the exterior of the ring plasma chamber, logic for
generating magnetic field in the primary winding, logic for
concentrating the magnetic field with the ferrites, wherein the
ring plasma chamber passes through each of the ferrites, logic for
inducing a secondary current in the process gas in the ring plasma
chamber, logic for generating a plasma in the process gas in the
ring plasma chamber with the secondary current, logic for receiving
a process feedback signal from at least one process monitoring
sensor, and logic for adjusting at least one set point of at least
one of the plasma sources.
[0026] Yet another embodiment provides a plasma system for
processing a substrate including a process chamber having a base, a
plurality of sidewalls, a substrate support proximate to the base
and a chamber top interfaced with the sidewalls to enclose the
process chamber, multiple plasma sources are disposed over the
chamber top, such that the plasma sources are distributed over
regions of the substrate support, the regions extending at least
between an exterior portion of the substrate support and a center
portion of the substrate support.
[0027] Other aspects and advantages of the invention will become
apparent from the following detailed description, taken in
conjunction with the accompanying drawings, illustrating by way of
example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The present invention will be readily understood by the
following detailed description in conjunction with the accompanying
drawings.
[0029] FIG. 1A is a side view of a typical parallel-plate,
capacitive, plasma processing chamber.
[0030] FIG. 1B is a top view of a substrate processed in the
typical parallel-plate, capacitive, plasma processing chamber.
[0031] FIG. 2A is a perspective view of a plasma source, in
accordance with an embodiment of the present invention.
[0032] FIG. 2B is a top view of a plasma source, in accordance with
an embodiment of the present invention.
[0033] FIG. 2C is a sectional view 2C-2C of a plasma source, in
accordance with an embodiment of the present invention.
[0034] FIG. 2D is a perspective sectional view of a plasma source,
in accordance with an embodiment of the present invention.
[0035] FIG. 2E is a perspective view of a plasma source mounted on
a process chamber, in accordance with an embodiment of the present
invention.
[0036] FIGS. 2F and 2G are additional perspective views of a plasma
source 200 mounted on a process chamber, in accordance with an
embodiment of the present invention.
[0037] FIG. 2H is another perspective view of a plasma source
mounted on a process chamber 230, in accordance with an embodiment
of the present invention.
[0038] FIG. 2I shows multiple sectional views of the plasma chamber
outlets, in accordance with embodiments of the present
invention.
[0039] FIG. 2J is a process chamber view of multiple plasma chamber
outlets, in accordance with embodiments of the present
invention.
[0040] FIG. 3A is a perspective view of another plasma source, in
accordance with an embodiment of the present invention.
[0041] FIG. 3B is a top perspective view of a multizone plasma
source, in accordance with an embodiment of the present
invention.
[0042] FIG. 3C is a bottom perspective view of multizone plasma
source, in accordance with an embodiment of the present
invention.
[0043] FIG. 3D is a top perspective view of another multizone
plasma source, in accordance with an embodiment of the present
invention.
[0044] FIG. 3E is a bottom perspective view of multizone plasma
source, in accordance with an embodiment of the present
invention.
[0045] FIGS. 4A and 4B are simplified schematic views of multizone
plasma sources, in accordance with an embodiment of the present
invention.
[0046] FIG. 5 is a flow and pressure graph for various sizes of the
optional plasma restriction, in accordance with an embodiment of
the present invention.
[0047] FIG. 6A is a schematic of an exemplary transformer, in
accordance with an embodiment of the present invention.
[0048] FIG. 6B is a schematic of a single ring of ferrites and
plasma chamber in a plasma source, in accordance with an embodiment
of the present invention.
[0049] FIG. 7 is an electrical schematic of a single ring of
ferrites and plasma chamber in a multizone plasma source, in
accordance with an embodiment of the present invention
[0050] FIG. 8 is an electrical schematic of a power supply, in
accordance with an embodiment of the present invention.
[0051] FIGS. 9A-9C are flow diagrams of the flow from the plasma
source, in accordance with an embodiment of the present
invention.
[0052] FIG. 10 is a flowchart diagram that illustrates the method
operations performed in operation of the plasma sources described
herein, in accordance with one embodiment of the present
invention.
[0053] FIG. 11 is a block diagram of an integrated system including
one or more of the plasma sources described herein, in accordance
with an embodiment of the present invention.
[0054] FIG. 12A is a top view of a multi-zone plasma source, in
accordance with an embodiment of the present invention.
[0055] FIG. 12B is a top view of a multi-zone plasma source, in
accordance with an embodiment of the present invention.
[0056] FIG. 12C is a top view of a multi-zone plasma source, in
accordance with an embodiment of the present invention.
[0057] FIG. 12D is a top view of a multi-zone plasma source, in
accordance with an embodiment of the present invention.
[0058] FIG. 13 is a flowchart diagram that illustrates the method
operations performed in operation of the plasma sources, in
accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
[0059] Several exemplary embodiments for a distributed multi-zone
plasma source system, method and apparatus will now be described.
It will be apparent to those skilled in the art that the present
invention may be practiced without some or all of the specific
details set forth herein.
[0060] FIG. 2A is a perspective view of a plasma source 200, in
accordance with an embodiment of the present invention. The plasma
source 200 includes a process gas inlet 206, multiple ferrites 204,
a plasma source top 208 and a chamber top 202. It should be
understood that the specific arrangement of the elements 202-208 of
the plasma source 200 might be modified from what is shown. For
example, the chamber top 202 and the plasma source top 208 could be
combined into a single cover of the process chamber 230.
[0061] FIG. 2B is a top view of a plasma source 200, in accordance
with an embodiment of the present invention. FIG. 2C is a sectional
view 2C-2C of a plasma source 200, in accordance with an embodiment
of the present invention. FIG. 2D is a perspective sectional view
of a plasma source 200, in accordance with an embodiment of the
present invention. FIG. 2E is a perspective view of a plasma source
200 mounted on a process chamber 230, in accordance with an
embodiment of the present invention. A process gas plenum 212 is
shown as a distributing plenum for the process gas supplied from
the process gas inlet 206.
[0062] Process gas 110 flows into the inlet port 206 to the process
gas plenum 212. The process gas plenum 212 distributes the process
gas 110 to inlet ports 212A. The inlet ports 212A direct the
process gas 110 into the plasma chamber 210. The process gas inlet
ports 212A can be aligned with or offset from the plasma chamber
outlets 220. The process gas inlet ports 212A and/or the plasma
chamber outlets 220 can be located between the ferrites 204 or
aligned with the ferrites or combinations thereof.
[0063] The ferrites 204 wrap around the plasma chamber 210 at
selected intervals. The ferrites 204 concentrate the magnetic field
sufficient to cause the electric field proximate to the center of
each ferrite to be strong enough to support a plasma at a
corresponding point in the plasma chamber 210.
[0064] The ferrites 204 are shown as being substantially square
however, as will be shown below, the ferrites can be other shapes.
The ferrites 204 are shown as being made in multiple parts 224A,
224B, 224C, 224D, however the ferrites can be in one or more parts.
The multiple ferrite parts 224A, 224B, 224C, 224D are substantially
close together as required to concentrate the electric field
proximate to the center of each ferrite 204. The ferrites 204 are
shown distributed about the chamber top 202. The process chamber
230 has sidewalls 230' and base 230''. The substrate support 106 is
on or near or proximate to the base 230''.
[0065] Plasma chamber outlets 220 are shown coupling the plasma
chamber 210 to the process chamber 230 below the chamber top 202.
The plasma chamber outlets 220 deliver plasma and/or radical and/or
neutral species from the plasma chamber 210 and into the process
chamber 230.
[0066] An optional plasma restriction 214 is also shown. The
optional plasma restriction 214 can be used to provide a desired
pressure differential between the plasma chamber 210 and the
process chamber 230. The optional plasma restriction 214 can also
be small enough and/or be biased such that plasma is substantially
prevented from passing from the plasma chamber 210 to the process
chamber 230. In addition, the plasma restriction can be biased to
extract ions from the plasma chamber 210 and draw the ions into the
process chamber and then onto the wafer. By way of example the
optional plasma restriction 214 can have a diameter that is less
than or equal to twice a plasma sheath thickness and thus the
plasma sheath can prevent the plasma from passing through the
optional plasma restriction. The optional plasma restriction 214
can have a selected diameter between about 0.1 mm and about 2.0 mm
(e.g., 0.1 mm, 0.2 mm, 0.5 mm, 1.0 mm, 2.0 mm). It should be noted
that the aspect ratio of the optional plasma restriction 214 can be
used to adjust the effectiveness of plasma restriction. By way of
example, a higher aspect ratio (i.e., length/width) plasma
restriction 214 can substantially restrict the plasma while having
minimal impact on neutral or radical species transport. It should
also be understood that larger diameter outlet orifices are can
also be used. By way of example the optional plasma restriction 214
can be omitted and the effective restriction is the width of the
plasma chamber outlets 220. The width of the plasma chamber outlets
220 can be substantially wide enough to allow a substantially equal
pressure in both the plasma chamber 210 and the process chamber
230.
[0067] FIG. 2I shows multiple sectional views of the plasma chamber
outlets 220, in accordance with embodiments of the present
invention. FIG. 2J is a process chamber view of multiple plasma
chamber outlets 220, in accordance with embodiments of the present
invention. The plasma chamber outlets 220 can be a straight
through, substantially cylindrical with a substantially
rectangular, cross-sectional shape of the desired width. The plasma
chamber outlets 220 can include an optional conical shape 220A. The
optional conical shape 220A can provide flow smoothing and/or flow
distribution from the plasma chamber outlets 220. The plasma
chamber outlets 220 can also include other optional shapes. By way
of example the plasma chamber outlets 220 can include a larger
width of the same shape 220B or a smaller width of the same shape
220F. The plasma chamber outlets 220 can include an optional curved
or bowl shaped outlet 220C, 220E. The optional curved or bowl
shaped outlet 220C, 220E can have an opening at the widest point
such as outlet 220C or at a narrower point less than the widest
point such as outlet 220E. The optional conical shape can be a
truncated conical shape 220D.
[0068] The optional plasma restriction can be located substantially
central along the length of the outlet port 220 such as the
optional plasma restriction 214. Alternatively, the optional plasma
restriction can be located substantially at the plasma chamber 210
end of the outlet port 220 such as the optional plasma restriction
214'. Alternatively, the optional plasma restriction can be located
substantially at the process chamber 230 end of the outlet port 220
such as the optional plasma restriction 214''. It should be
understood that the optional plasma restriction 214 can be located
anywhere along the length of the outlet port 220 between the plasma
chamber 210 end and the process chamber 230 end of the outlet port
220.
[0069] As shown in FIG. 2J, the plasma chamber outlet 220 can be
any suitable shape. By way of example, substantially round 220,
substantially elliptical 220H, substantially rectangular 220I,
220J, or other geometrical shapes (e.g., triangular 220K, polygon
of any number of sides 220L). The plasma chamber outlet 220 can
include substantially sharp edges 220I, 220K, 220L or substantially
curved edges and/or sides 220J, 220M, 220N. Combination of shapes
can also be included in the plasma chamber outlet 220. By way of
example optional conical shape 220A can have a more elliptical
shape 220A' rather than a substantially round shape 220A.
[0070] The chamber top 202 can also include one or more outlets
234. The outlets 234 are coupled to a lower pressure source (e.g.,
a vacuum pump). The outlets 234 allow the lower pressure source to
withdraw the plasma byproducts 118 and recombination products 120
from near the center of the process chamber 230. As a result, the
plasma byproducts 118 and recombination products 120 do not
interfere with the plasma 410 and the neutral species 412 generated
by the plasma in the process chamber. The chamber top 202 can be
made from multiple layers 202A-202C of materials. At least one of
the layers (e.g., any one or more of 202A, 202B or 202C) of
materials can be conductive and the conductive layer (e.g., 202B)
can be biased with a desired signal. The conductive layer (e.g.,
202B) can also be coupled to a ground potential. As a result at
least a portion of the outlets 234 that pass through the conductive
layer (e.g., 202B) can be biased with a desired bias signal or
coupled to a ground potential. The desired biasing can assist in
pulling the radicals into the processing chamber.
[0071] The process chamber 230 includes load ports 232 and support
structure for supporting the substrate to be processed. Other
features may also be included in the process chamber 230 as are
well known in the art.
[0072] FIGS. 2F and 2G are additional perspective views of a plasma
source 200 mounted on a process chamber 230, in accordance with an
embodiment of the present invention. The plasma source top 208 is
shown lifted (FIG. 2F) and removed (FIG. 2G) for description of
additional details. The plasma chamber 210 can be constructed of a
different material than the plasma source top 208 or the process
chamber 230. By way of example, the plasma chamber 210 can be a
ceramic and the plasma source top 208 or the process chamber 230
could be ceramic, metal (e.g., aluminum, steel, stainless steel,
etc.). Slots 226A and 226B are provided for the support and
installation of the ferrites 204.
[0073] As shown in FIG. 2G the ferrites 204 are shown wrapping
around the exterior of plasma chamber 210. The plasma chamber 210
can be formed of a dielectric such as a ceramic or other dielectric
material (e.g., quartz, silica (siO2), alumina (Al2O3), sapphire
(Al2O3), aluminum nitride (AlN), yttrium oxide (Y2O3) and/or
similar materials and combinations thereof).
[0074] FIG. 2H is another perspective view of a plasma source 200
mounted on a process chamber 230, in accordance with an embodiment
of the present invention. As shown in FIG. 2H, a primary conductor
240 is shown wrapped around the plasma chamber 210. The primary
conductor 240 is the primary winding of an inductive element as
will be described in more detail in FIG. 7 below. The primary
conductor 240 has one or more turns around the plasma chamber 210.
As shown here, the primary conductor 240 has two turns around the
plasma chamber 210, however more than two turns could also be
used.
[0075] FIG. 3A is a perspective view of another plasma source 300,
in accordance with an embodiment of the present invention. The
plasma source 300 includes plasma chamber 210 having multiple
ferrite elements 204 surrounding the plasma chamber at selected
intervals. In this instance the ferrite elements 204 surrounding
the plasma chamber at substantially equal intervals but they could
be at different intervals.
[0076] The plasma chamber 210 can be roughly circular or
geometrically shaped, such as in this instance, having five sides.
Similarly, the plasma chamber 210 could be circular or three or
more sided geometrical shapes. It should also be noted that the
plasma chamber 210 could have an approximately rectangular or
approximately circular or rounded cross-sectional shape. The inner
surfaces of the plasma chamber 210 can be smoothed and without any
sharp (e.g., about perpendicular or more acute angle) edges or
corners. By way of example, the inner corners can have a rounded
contour with a relatively large radius (e.g. between about 1/2 and
about twice the radius of a cross-section of the plasma chamber).
It should also be noted that while a single process gas inlet 206
is shown coupled to the plasma chamber 210, two or more process gas
inlet's could be used to supply process gas to the plasma
chamber.
[0077] FIG. 3B is a top perspective view of a multizone plasma
source 320, in accordance with an embodiment of the present
invention. The multizone plasma source 320 includes multiple,
individual, concentric plasma chambers 310A-310D, e.g., in nested
rings. Each of the concentric plasma chambers 310A-310D has a
corresponding set of ferrites 204A-204D.
[0078] FIG. 3C is a bottom perspective view of multizone plasma
source 320, in accordance with an embodiment of the present
invention. The chamber top 202 has multiple process outlet ports
304A-304E and multiple plasma outlet ports 220A-220D. The multiple
plasma outlet ports 220A-220D are coupled to corresponding plasma
chambers 310A-310D.
[0079] FIG. 3D is a top perspective view of another multizone
plasma source 330, in accordance with an embodiment of the present
invention. FIG. 3E is a bottom perspective view of multizone plasma
source 330, in accordance with an embodiment of the present
invention. The multizone plasma source 330 includes multiple
concentric plasma chambers 310A-310E. Each of the concentric plasma
chambers 310A-310E has a corresponding set of ferrites
204A-204E.
[0080] As shown the ferrites 204A-204E of adjacent plasma chambers
310A-310E can overlap slightly as shown in regions 332A-332D. By
way of example, inner edges of ferrites 204B overlap the outer
edges of ferrites 204A in region 332A. Similarly, outer edges of
ferrites 204B overlap the inner edges of ferrites 204C in region
332B. The overlapping ferrites 204A-204E allow the concentric
plasma chambers 310A-310E to be more closely packed in the
multizone plasma source 330. Thus allowing more concentric rings
310A-310E (e.g., five concentric rings) to be included in the same
diameter as non-overlapping ferrite embodiment shown in FIGS. 3B
and 3C having only four concentric rings 310A-310D. As will be
described below, each ring 310A-310E can be individually controlled
in bias, gas flow, concentration, RF power, etc. Thus, a greater
number of concentric rings 310A-310E provides a more fine tuning
control of the process across the diameter of the substrate 102 in
the process chamber 230.
[0081] The ferrites 204A-204E can optionally be arranged in
multiple radial segments (i.e., pie slice shapes) 334A-334L of the
multizone plasma source 330. As will be described below, each
radial segment 334A-334L can be individually controlled in bias,
gas flow, concentration, etc. Thus, the radial segments 334A-334L
provide yet another fine tuning control of the process radially
across the substrate 102 in the process chamber 230.
[0082] FIGS. 4A and 4B are simplified schematic views of multizone
plasma sources 300, 320, in accordance with an embodiment of the
present invention. The chamber top 202 includes the multizone
plasma sources 300, 320. The process chamber 230 has sidewalls 230'
and base 230''. The substrate support 106 is on or near or
proximate to the base 230''. The process outlet ports 304A-304E
withdraw the plasma byproducts 118 and recombination products 120
substantially equally across the width W of the substrate 102. As a
result, the plasma byproducts 118 and recombination products 120 do
not interfere with the plasma 410 and the neutral species 412
generated by the plasma. The neutral species 412 are therefore
substantially evenly distributed across the width of the substrate
102. The neutral species 412 react with the surface of the
substrate 102. As the neutral species 412 are substantially evenly
distributed across the width of the substrate 102, the
center-to-edge non-uniformities of the plasma processes (e.g.,
etch, strip or other plasma processes) applied in the processing
chamber 230 are also substantially eliminated.
[0083] A controller 420 includes corresponding controls 422A-422E
(e.g., software, logic, set points, recipes, etc.) for each ring
310A-310E. Process monitoring sensors 424, 426 can also be coupled
to the controller 420 to provide a process feedback. The controls
422A-422E can individually control each ring 310A-310E such as a
bias signal, power, frequency, process gas 110 pressures, flow
rates and concentrations. Thus providing a radial profile control
of dissociated gas across the diameter of the substrate 102 in the
process chamber 230.
[0084] Each of the multiple plasma chambers 310A-310E can be
controlled independently to manipulate the processes in the
corresponding region of the processing chamber 230.
[0085] Similarly, each of the multiple radial segments 334A-334L
allows each radial segment of the multiple plasma chambers
310A-310E to be controlled independently to manipulate the
processes in the corresponding region of the processing chamber
230. By way of example, a process variable set point for the flow
rate and pressure of the process gas 110 in the plasma chamber 310B
is input to the corresponding control 422B. At least one of the
process monitoring sensors 424, 426 provides a process measurement
input to the corresponding control 422B. Based on the process
measurement input from the process monitoring sensors 424, 426 and
the logic and software, the corresponding control 422B then outputs
revised setpoints for the RF power to ferrites 310B and the flow
rate and the pressure of the process gas 110 in the plasma chamber
310B.
[0086] Similarly, the processes can be monitored and/or controlled
in each of the respective regions defined by one or more or a
combination of the concentric ring plasma chambers 310A-E, and/or
the ferrites 204A-E, and/or the radial segments 334A-334L of the
multizone plasma sources 200, 300, 310, 320, 330. It should also be
understood that each of the zones could be operated in the same
manner and setpoints so that the multizone plasma sources 200, 300,
310, 320, 330 are effectively a single zone plasma source. Further,
some of the zones of the multizone plasma sources 200, 300, 310,
320, 330 can be operated in the same manner and setpoints so that
the multizone plasma sources have less zones.
[0087] FIG. 5 is a flow and pressure graph for various sizes of the
optional plasma restriction 214, in accordance with an embodiment
of the present invention. Graph 510 is the flow rate in standard
cubic centimeters per minute (SCCM) for an optional plasma
restriction 214 having a diameter of 0.2 mm. Graph 520 is the flow
rate for an optional plasma restriction 214 having a diameter of
0.5 mm. Graph 530 is the flow rate for an optional plasma
restriction 214 having a diameter of 1.0 mm. As can be seen, the
various sizes of the optional plasma restriction 214 can determine
a pressure drop between the plasma chamber 210 and the process
chamber 230. If the pressure drop is such that choked flow occurs
across the plasma restriction 214, the mass flow rate into the
process chamber 210 will not increase with a decrease in the plasma
chamber when pressure in the plasma chamber 210 is constant.
[0088] Increasing the pressure in the plasma chamber 210 provides
the density of the process gas 110 sufficient to support a plasma
in the plasma chamber. For a fixed RF voltage, the current required
to be induced into the process gas 110 is inversely proportional to
the process gas pressure. Therefore, increasing the process gas 110
pressure in the plasma chamber 210 reduces the current required to
produce the plasma. Further, since the plasma requires the process
gas pressure to support the plasma, then the plasma will be
contained in the plasma chamber 210 and will not flow from the
plasma chamber into the process chamber 230. As a result, the
plasma restriction 214 can restrict the plasma to the plasma
chamber 210.
[0089] A transformer has a primary winding and a secondary winding.
A primary current through the primary winding generates a magnetic
field. As the magnetic field passes through the secondary winding,
a corresponding secondary current is induced into the secondary
winding. A transformer with a ferrite core, concentrates (i.e.,
focuses) the magnetic field to a smaller, denser magnetic field and
therefore more efficiently induces the secondary current into the
secondary winding. This allows for very efficient low frequency
operation (e.g., less than about 13 MHz and more specifically
between 10 kHz and less than about 5 MHz and more specifically
between about 10 kHz and less than about 1 MHz). The low frequency
operation also provides significantly lower cost relative to
typical high frequency RF plasma systems (e.g., about 13.56 MHz and
higher frequencies).
[0090] A further advantage of low frequency ferrite coupled plasma
systems is their low ion bombardment energies, which results in
less plasma erosion and fewer on-wafer particulates relative to a
high-frequency RF system. Less plasma erosion results in less wear
and tear on the plasma chamber 210 surfaces and components.
[0091] FIG. 6A is a schematic of an exemplary transformer 600, in
accordance with an embodiment of the present invention. A primary
current I.sub.p is applied to the primary winding 620 from a power
supply. The flow of the primary current I.sub.p through the primary
winding 620 produces a magnetic field 622 into the ferrite 204. The
magnetic field 622 emerges from the ferrite in the center of the
secondary winding 630 and induces a secondary current I.sub.s in
the secondary winding.
[0092] FIG. 6B is a schematic of a single ring of ferrites 204 and
plasma chamber 210 in a plasma source 200, 300, 310, 320, 330, in
accordance with an embodiment of the present invention. FIG. 7 is
an electrical schematic 700 of a single ring of ferrites 204 and
plasma chamber 210 in a plasma source 200, 300, 310, 320, 330, in
accordance with an embodiment of the present invention. In the
plasma sources 200, 300, 310, 320, 330, described herein, the
primary winding 240 is wrapped around each plasma chamber 210 and
inside each respective set of ferrites 204, 204A-E. The secondary
winding is the process gas 110 inside the plasma chamber 210.
[0093] A primary current I.sub.p is applied to the primary winding
240 from a power supply 702. The power can be RF (e.g., about 10
kHz to about 1 MHz or more or between about 10 kHz to about 5 MHz
or between about 10 kHz to less than about 13 MHz). The flow of the
primary current I.sub.p through the primary winding 240 produces a
magnetic field 622 in the ferrites 204. The magnetic field 622
induces a secondary current I.sub.s in the process gas 110 inside
the plasma chamber 210. As a result, the process gas is excited
sufficiently to form a plasma 410.
[0094] FIG. 8 is an electrical schematic of a power supply 702, in
accordance with an embodiment of the present invention. The power
supply 702 includes a rectifier 804 for converting the AC power
from the power source 802 into a DC power. The filter 808 filters
the output of the rectifier 804. The filtered DC is delivered to
the inverter 810 from the filter 808. The inverter 810 converts the
filtered DC to an AC signal at the desired frequency, voltage and
current. A resonant circuit 812 matches resonance with the plasma
chamber load 814 so as to efficiently deliver the desired AC signal
to the load in resonance.
[0095] A controller 820 controls the power supply 702. The
controller 820 includes a user interface 822 that may include a
link (e.g., network) to a system controller or a larger area
control system (not shown). The controller 820 is coupled to the
Components 804, 808, 810, 812 directly and via sensors 806A, 806B,
806C for monitoring and controlling the operation thereof. By way
of example the controller 820 monitors one or more of the voltage,
current, power, frequency and phase of the power signals within the
power supply 702.
[0096] FIGS. 9A-9C are flow diagrams of the flow from the plasma
source 300, 310, 320, 330, in accordance with an embodiment of the
present invention. The radicals and neutrals flow 902 are shown
flowing from the plasma chamber 304A-F toward a substrate 102 in an
approximate fan shape. The fan shape begins at the outlet ports 220
and expands as it approaches the wafer 102. The gas flowing through
the plasma chamber 304A-F has a flowrate Q and a pressure Ps. The
pressure Pc is the pressure in the process chamber 230. The
difference between Ps and Pc allows the radicals and neutrals flow
902 to expand toward the wafer 102.
[0097] Referring now to FIG. 9B, the concentration 920 of the
radicals and neutrals flow 902 is a function of the distance L
between the outlet ports 220 and the height H of the process
chamber 230. If the distance L between the outlet ports 220 is too
great then there will be regions 904 where the concentration 920 of
the radicals and neutrals flow 902 is insufficient to react with
the surface of the wafer 102. Similarly, if the height H of the
process chamber 230 is too small, then there will be regions 904
where the concentration 920 of the radicals and neutrals flow 902
is insufficient to react with the surface of the wafer 102. FIG. 9C
shows an ideal relationship of Height H and distance L as
follows:
R = R ( x , H , L ) ##EQU00001## Where : R ( x ) = ( n total - n 0
) / n 0 ##EQU00001.2## and n total ( x ) = i n i ##EQU00001.3##
[0098] If distance L is approximately equal to height H/2 the
variation of concentration of the radicals and neutrals across the
surface of the wafer can be minimized. Alternatively, increasing or
decreasing the relationship of distance L and height H can allow
variation in concentration of the radicals and neutrals across the
surface of the wafer.
[0099] FIG. 10 is a flowchart diagram that illustrates the method
operations performed in operation of the plasma source 200, 300,
310, 320, 330, in accordance with one embodiment of the present
invention. The operations illustrated herein are by way of example,
as it should be understood that some operations may have
sub-operations and in other instances, certain operations described
herein may not be included in the illustrated operations. With this
in mind, the method and operations 1000 will now be described.
[0100] In an operation 1005, a process gas 110 is delivered to a
plasma chamber 210. In an operation 1010, the process gas 110 is
maintained at a first pressure in the plasma chamber 210. The first
pressure can be the same as or up to twice or more multiples of a
pressure of a process chamber 230 coupled to a set of outlet ports
220 of the plasma chamber.
[0101] In an operation 1015, a primary current I.sub.p is applied
to a primary winding 240 wrapped around the external circumference
of the plasma chamber 210. In an operation 1020, the primary
current I.sub.p generates a magnetic field. In an operation 1025,
one or more ferrites 204 concentrate the magnetic field to the
approximate center portion of the plasma chamber 210. The ferrites
204 are formed around the plasma chamber 230.
[0102] In an operation 1030, the magnetic field induces a secondary
current I.sub.s in the process gas 110 in the plasma chamber 210.
In an operation 1035, the secondary current I.sub.s generates a
plasma in the process gas 110 in the plasma chamber 210. In an
operation 1040, a portion of the plasma and plasma generated
radicals and neutrals pass from the plasma chamber 210 through the
plasma chamber outlets 220 and into the process chamber 230.
[0103] In an operation 1045, the radicals and neutrals interact
with a substrate 102 and the processing chamber 230 to produce
plasma byproducts 118 and recombination products 120. In an
operation 1050, the plasma byproducts 118 and the recombination
products 120 are drawn out of the processing chamber through one or
more process outlet ports 304A-304E. The one or more process outlet
ports 304A-304E are distributed across the surface of the process
chamber top 202 or along the edges of the substrate support 106 or
below the substrate support such as in the base of the process
chamber or combinations thereof and the method operations can
end.
[0104] FIG. 11 is a block diagram of an integrated system 1100
including the plasma sources 200, 300, 320, in accordance with an
embodiment of the present invention. The integrated system 1100
includes the plasma sources 200, 300, 320, and an integrated system
controller 1110 coupled to the plasma sources. The integrated
system controller 1110 includes or is coupled to (e.g., via a wired
or wireless network 1112) a user interface 1114. The user interface
1114 provides user readable outputs and indications and can receive
user inputs and provides user access to the integrated system
controller 1110.
[0105] The integrated system controller 1110 can include a special
purpose computer or a general purpose computer. The integrated
system controller 1110 can execute computer programs 1116 to
monitor, control and collect and store data 1118 (e.g., performance
history, analysis of performance or defects, operator logs, and
history, etc.) for the plasma sources 200, 300, 320. By way of
example, the integrated system controller 1110 can adjust the
operations of the plasma sources 200, 300, 320 and/or the
components therein (e.g., the one of the concentric ring plasma
chambers 310A-E or ferrites 204, 204A-E, etc.) if data collected
dictates an adjustment to the operation thereof.
[0106] FIG. 12A is a top view of a multi-zone plasma source 1200,
in accordance with an embodiment of the present invention. FIG. 12B
is a top view of a multi-zone plasma source 1260, in accordance
with an embodiment of the present invention. FIG. 12C is a top view
of a multi-zone plasma source 1270, in accordance with an
embodiment of the present invention. FIG. 12D is a top view of a
multi-zone plasma source 1280, in accordance with an embodiment of
the present invention.
[0107] Each of the multi-zone plasma sources 1200, 1260, 1270, 1280
includes multiple zones 1202-1212 in a plasma processing chamber
top 1201. Each of the zones 1202-1212 includes a respective plasma
source 200, 300, 300', 320, 330 as described above. The plasma
processing chamber top 1201 can also include multiple outlets 1219.
The multiple outlets 1219 can be distributed across the area of the
plasma processing chamber top 1201. At least one of the multiple
outlets 1219 can be located in a substantially central location in
the process chamber top 1201.
[0108] Each of the plasma sources 200, 300, 300', 320, 330 can be
independently controlled to selectively apply different plasma
reactions and reaction products (e.g., radicals and neutrals that
can interact with a surface 1220 of a substrate 102) in each
respective zone 1202-1210. Thereby selectively processing each
respective zone 1222-1232 of the surface 1220 being processed. By
way of example, plasma source 200, 300, 300', 320, 330 can be
individually controlled in bias, gas flow, concentration, RF power,
etc. Thus, providing a more fine tuning control of the process
across the surface 1220 of the substrate 102.
[0109] The zones 1202-1212 can be arranged in any desired
configuration such as a substantially rectangular array as shown in
FIG. 12A, a linear array 1260 as shown in FIG. 12B or one or more
alternative patterns 1270 and 1280 as shown in FIGS. 12C and 12D
and combinations of patterns 1250, 1260, 1270, 1280 or any other
suitable pattern.
[0110] It should be understood that only six zones 1202-1212 are
illustrated for simplicity of discussion. More or less than six
zones 1202-1212 could also be utilized. Each of the zones 1202-1212
can be substantially similar in size as shown in FIG. 12A or vary
in size from one zone to the next as shown in FIG. 12C. Similarly
the respective plasma sources 200, 300, 300', 320, 330 can be
substantially similar in size as shown in FIG. 12A or vary in size
from one source to the next as shown in FIG. 12C. The spacing S1,
S2, S3 between the respective plasma sources 200, 300, 300', 320,
330 can be substantially similar in size as shown in FIG. 12A or
vary in size from one source to the next as shown in FIG. 12C.
[0111] The surface 1220 being processed can be fixed or movable
relative to the multiple zones 1202-1212. By way of example, the
surface 1220 being processed can be supported on a movable support
(hidden under the surface 1220) that moves the surface linearly
such as in directions 1262A-D as shown in FIG. 12B. Alternatively,
the surface 1220 being processed can be supported on a movable
support that rotates the surface such as in directions 1282A-B as
shown in FIG. 12D.
[0112] FIG. 13 is a flowchart diagram that illustrates the method
operations 1300 performed in operation of the plasma sources 200,
300, 300', 320, 330, in accordance with one embodiment of the
present invention. The operations illustrated herein are by way of
example, as it should be understood that some operations may have
sub-operations and in other instances, certain operations described
herein may not be included in the illustrated operations. With this
in mind, the method and operations 1300 will now be described.
[0113] In an operation 1305, a process gas 110 is delivered to at
least one of the plasma chambers 200, 300, 300', 320, 330. In an
operation 1310, the process gas 110 is maintained at a first
pressure in the least one of the plasma chambers 200, 300, 300',
320, 330.
[0114] In an operation 1315, a primary current I.sub.p is applied
to a respective primary winding wrapped around the external
circumference of each of the plasma chambers 200, 300, 300', 320,
330. In an operation 1320, the primary current I.sub.p generates a
magnetic field.
[0115] In an operation 1325, one or more ferrites in the selected
plasma chamber 200, 300, 300', 320, 330 concentrates the magnetic
field to the approximate center portion of the plasma chamber.
[0116] In an operation 1330, the magnetic field induces a secondary
current I.sub.s in the process gas 110 in the plasma chamber 200,
300, 300', 320, 330. In an operation 1335, the secondary current
I.sub.s generates a plasma in the process gas 110 in the plasma
chamber 210. In an operation 1340, a portion of the plasma and
plasma generated radicals and neutrals pass from the plasma chamber
200, 300, 300', 320, 330 and into the process chamber 230.
[0117] In an operation 1345, the radicals and neutrals generated in
the selected plasma chamber interact with the respective zone
1222-1234 of the surface 1220 of the substrate 102 to produce
plasma byproducts 118 and recombination products 120. In an
operation 1350, is an inquiry to determine if additional plasma
sources are to be activated. In an operation 1355, a subsequent
plasma chamber 200, 300, 300', 320, 330 is selected and the method
operations continue in operations 1305-1345.
[0118] In an operation 1360, each of the local processes in each of
the respective zones 1222-1234 are monitored and adjusted in
operation 1365, as needed. In an operation 1370, the surface 1220
is moved in at least one of direction 1262A-1262D and/or directions
1282A, 1282B, relative to the plasma sources 200, 300, 300', 320,
330.
[0119] In an operation 1370, byproducts 118 and the recombination
products 120 are drawn out of the processing chamber through one or
more process outlet ports 304A-304E. The one or more process outlet
ports 304A-304E are distributed across the surface of the process
chamber top 202 or along the edges of the substrate support 106 or
below the substrate support such as in the base of the process
chamber or combinations thereof and the method operations can
end.
[0120] With the above embodiments in mind, it should be understood
that the invention may employ various computer-implemented
operations involving data stored in computer systems. These
operations are those requiring physical manipulation of physical
quantities. Usually, though not necessarily, these quantities take
the form of electrical or magnetic signals capable of being stored,
transferred, combined, compared, and otherwise manipulated.
Further, the manipulations performed are often referred to in
terms, such as producing, identifying, determining, or
comparing.
[0121] Any of the operations described herein that form part of the
invention are useful machine operations. The invention also relates
to a device or an apparatus for performing these operations. The
apparatus may be specially constructed for the required purposes,
or it may be a general-purpose computer selectively activated or
configured by a computer program stored in the computer. In
particular, various general-purpose machines may be used with
computer programs written in accordance with the teachings herein,
or it may be more convenient to construct a more specialized
apparatus to perform the required operations.
[0122] The invention can also be embodied as computer readable code
and/or logic on a computer readable medium. The computer readable
medium is any data storage device that can store data which can
thereafter be read by a computer system. Examples of the computer
readable medium include hard drives, network attached storage
(NAS), logic circuits, read-only memory, random-access memory,
CD-ROMs, CD-Rs, CD-RWs, magnetic tapes, and other optical and
non-optical data storage devices. The computer readable medium can
also be distributed over a network coupled computer systems so that
the computer readable code is stored and executed in a distributed
fashion.
[0123] It will be further appreciated that the instructions
represented by the operations in the above figures are not required
to be performed in the order illustrated, and that all the
processing represented by the operations may not be necessary to
practice the invention. Further, the processes described in any of
the above figures can also be implemented in software stored in any
one of or combinations of the RAM, the ROM, or the hard disk
drive.
[0124] Although the foregoing invention has been described in some
detail for purposes of clarity of understanding, it will be
apparent that certain changes and modifications may be practiced
within the scope of the appended claims. Accordingly, the present
embodiments are to be considered as illustrative and not
restrictive, and the invention is not to be limited to the details
given herein, but may be modified within the scope and equivalents
of the appended claims.
* * * * *