U.S. patent application number 10/446332 was filed with the patent office on 2004-12-02 for method for removal of residue from a substrate.
This patent application is currently assigned to Applied Materials, Inc.. Invention is credited to Arias, Suzanne, Ding, Guowen, Rui, Ying, Yan, Chun.
Application Number | 20040237997 10/446332 |
Document ID | / |
Family ID | 33451019 |
Filed Date | 2004-12-02 |
United States Patent
Application |
20040237997 |
Kind Code |
A1 |
Rui, Ying ; et al. |
December 2, 2004 |
Method for removal of residue from a substrate
Abstract
A method for removing residues from a substrate. The residue is
removed by exposing the substrate to a hydrogen-based plasma. After
the substrate is exposed to the hydrogen-based plasma, the
substrate may optionally be immersed in an aqueous solution
including hydrogen fluoride.
Inventors: |
Rui, Ying; (Sunnyvale,
CA) ; Yan, Chun; (San Jose, CA) ; Ding,
Guowen; (Sunnyvale, CA) ; Arias, Suzanne;
(Fremont, CA) |
Correspondence
Address: |
MOSER, PATTERSON & SHERIDAN, LLP
APPLIED MATERIALS INC
595 SHREWSBURY AVE
SUITE 100
SHREWSBURY
NJ
07702
US
|
Assignee: |
Applied Materials, Inc. ;
|
Family ID: |
33451019 |
Appl. No.: |
10/446332 |
Filed: |
May 27, 2003 |
Current U.S.
Class: |
134/1.1 ; 134/2;
134/26; 134/30; 257/E21.011; 257/E21.253 |
Current CPC
Class: |
H01L 28/60 20130101;
B08B 3/08 20130101; B08B 7/0035 20130101; H01L 21/31122 20130101;
H01L 21/02071 20130101 |
Class at
Publication: |
134/001.1 ;
134/002; 134/026; 134/030 |
International
Class: |
C25F 001/00 |
Claims
What is claimed is:
1. A method for removing residue from a substrate, comprising:
providing a substrate having a metallic residue thereon; and
exposing the substrate to a hydrogen-based plasma to volatize the
metallic residue.
2. The method of claim 1 wherein the metallic residue comprises at
least one of a metal-containing residue and a polymeric
residue.
3. The method of claim 2 wherein the metal-containing residue
comprises at least one metal selected from the group consisting of
tantalum (Ta), titanium (Ti), tungsten (W) and hafnium (Hf).
4. The method of claim 1 wherein the hydrogen-based plasma
comprises at least one of hydrogen (H.sub.2), water vapor
(H.sub.2O).
5. The method of claim 1 wherein the hydrogen-based plasma
comprises hydrogen (H.sub.2) and water vapor (H.sub.2O) at a
H.sub.2:H.sub.2O flow ratio in a range from 20:1 to 100% of
H.sub.2.
6. The method of claim 1 wherein the exposing step comprises:
providing hydrogen (H.sub.2) and water vapor (H.sub.2O) at a
H.sub.2:H.sub.2O flow ratio in a range from 20:1 to 100% of
H.sub.2; maintaining the substrate at a temperature of about 100 to
300 degrees Celsius at a process chamber pressure between about 1
to 4 Torr; applying about 1000 to 2000 W of microwave power at
about 2.45 GHz to form the hydrogen-based plasma; and exposing the
substrate to the hydrogen-based plasma for about 40 to 200
seconds.
7. The method of claim 1 further comprising immersing the substrate
in an aqueous solution including hydrogen fluoride after exposing
the substrate to the hydrogen-based plasma.
8. The method of claim 7 wherein the aqueous solution comprises
between 0.5 and 12% by volume of hydrogen fluoride.
9. The method of claim 8 wherein the aqueous solution further
comprises between 0.5 and 15% by volume of nitric acid
(HNO.sub.3).
10. The method of claim 8 wherein the aqueous solution further
comprises between 0.5 and 15% by volume of hydrogen chloride
(HCl).
11. The method of claim 7 wherein the substrate is immersed in the
aqueous solution for about 1 to 10 minutes.
12. The method of claim 7 wherein the immersing step comprises:
immersing the substrate in an aqueous solution comprising between
0.5 and 12% by volume of hydrogen fluoride and deionized water at a
temperature of about 10 to 30 degrees Celsius for a duration of
about 0.5 to 5 minutes.
13. A method for removing metallic residue from a substrate,
comprising: providing a substrate having a metallic residue
thereon; exposing the substrate to a hydrogen-based plasma to
volatize the metallic residue; and immersing the substrate in an
aqueous solution including hydrogen fluoride.
14. The method of claim 13 wherein the metallic residue comprises
at least one of a metal-containing residue and a polymeric
residue.
15. The method of claim 14 wherein the metal-containing residue
comprises at least one metal selected from the group consisting of
tantalum (Ta), titanium (Ti), tungsten (W) and hafnium (Hf).
16. The method of claim 13 wherein the hydrogen-based plasma
comprises at least one of hydrogen (H.sub.2), water vapor
(H.sub.2O).
17. The method of claim 13 wherein the hydrogen-based plasma
comprises hydrogen (H.sub.2) and water vapor (H.sub.2O) at a
H.sub.2:H.sub.2O flow ratio in a range from 20:1 to 100% of
H.sub.2.
18. The method of claim 13 wherein the aqueous solution comprises
between 0.5 and 12% by volume of hydrogen fluoride.
19. The method of claim 18 wherein the aqueous solution further
comprises between 0.5 and 15% by volume of nitric acid
(HNO.sub.3).
20. The method of claim 18 wherein the aqueous solution further
comprises between 0.5 and 15% by volume of hydrogen chloride
(HCl).
21. The method of claim 13 wherein the substrate is immersed in the
aqueous solution for about 1 to 10 minutes.
22. The method of claim 13 wherein the exposing step comprises:
providing hydrogen (H.sub.2) and water vapor (H.sub.2O) at a
H.sub.2:H.sub.2O flow ratio in a range from 20:1 to 100% of
H.sub.2; maintaining the substrate at a temperature of about 100 to
300 degrees Celsius at a process chamber pressure between about 1
to 4 Torr; applying about 1000 to 2000 W of microwave power at
about 2.45 GHz to form the hydrogen-based plasma; and exposing the
substrate to the hydrogen-based plasma for about 40 to 200
seconds.
23. The method of claim 13 wherein the immersing step comprises:
immersing the substrate in an aqueous solution comprising between
0.5 and 12% by volume of hydrogen fluoride and deionized water at a
temperature of about 10 to 30 degrees Celsius for a duration of
about 0.5 to 5 minutes.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a method of
fabricating devices on semiconductor substrates. More specifically,
the invention relates to a method for removal of residue from a
semiconductor substrate.
[0003] 2. Description of the Related Art
[0004] Microelectronic devices are generally fabricated on a
semiconductor substrate as integrated circuits wherein various
metal layers are interconnected to one another to facilitate
propagation of electrical signals within the device. One typical
process used for fabrication of the microelectronic devices is a
plasma etch process. During plasma etch processes, one or more
layers that comprise a metal (e.g., tantalum (Ta), titanium (Ti),
and the like) or a metal-based compound (e.g., tantalum nitride
(TaN), titanium nitride (TiN), and the like) are removed, either
partially or in total, to form a feature (e.g., interconnect line
or contact via) of the integrated circuit.
[0005] Generally, plasma etch processes use gas chemistries that,
when reacted with the material comprising the etched layer or etch
mask, may produce non-volatile by-products. Such by-products
accumulate on the substrate as a residue. In the art, such residue
is commonly called a "post-etch residue." Post-etch residues
interfere with processing of the substrate, e.g., the residues may
contaminate the remaining layers or cause difficulties in
depositing subsequent layers. Metal-containing residue may also
cause short-circuits that disrupt or degrade operation of the
integrated circuits.
[0006] Conventional methods for removing residues typically include
multiple wet treatments of the substrate with an intermediate
plasma strip process using an oxygen-based chemistry. Multiple wet
treatments, along with an intermediate plasma strip process (i.e.,
etch and strip processes), reduce productivity during fabrication
of the microelectronic devices. Further, the oxygen-based plasma
strip process may form hard to remove metal oxides on the
substrate.
[0007] Therefore, there is a need in the art for an improved method
for removing residue from a substrate during fabrication of
microelectronic devices.
SUMMARY OF THE INVENTION
[0008] The present invention is a method for removing residue from
a substrate. The residue is removed by exposing the substrate to a
hydrogen-based plasma. After the substrate is exposed to the
hydrogen-based plasma, the substrate may optionally be immersed in
an aqueous solution including hydrogen fluoride. In one
application, the residue comprises at least one metal (e.g.,
tantalum (Ta), titanium (Ti), tungsten (W), hafnium (Hf), and the
like).
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The teachings of the present invention can be readily
understood by considering the following detailed description in
conjunction with the accompanying drawings, in which:
[0010] FIG. 1 depicts a flow diagram of a method for removing
residue in accordance with an embodiment of the present
invention;
[0011] FIGS. 2A-2D depict a sequence of schematic, cross-sectional
views of a substrate having a film stack where residue is removed
in accordance with the method of FIG. 1;
[0012] FIG. 3 depicts a schematic diagram of an exemplary plasma
processing apparatus of the kind used in performing portions of the
inventive method; and
[0013] FIG. 4 is a table summarizing the processing parameters of
one exemplary embodiment of the inventive method when practiced
using the apparatus of FIG. 3.
[0014] To facilitate understanding, identical reference numerals
have been used, where possible, to designate identical elements
that are common to the figures.
[0015] It is to be noted, however, that the appended drawings
illustrate only exemplary embodiments of this invention and are
therefore not to be considered limiting of its scope, for the
invention may admit to other equally effective embodiments.
DETAILED DESCRIPTION
[0016] The present invention is a method for removing residue from
a substrate (e.g., silicon (Si) wafer, gallium arsenide (GaAs)
wafer, and the like) during fabrication of a microelectronic
device. In one application, the inventive method is used to remove
post-etch residue that comprises at least one metal (e.g., tantalum
(Ta), titanium (Ti), tungsten (W), hafnium (Hf), and the like), as
well as compounds thereof.
[0017] FIG. 1 depicts a flow diagram of one embodiment of the
inventive method for removal of residue as sequence 100. The
sequence 100 includes processes performed upon a film stack having
at least one metal layer.
[0018] FIGS. 2A-2D depict a series of schematic, cross-sectional
views of a substrate having a film stack from which residue is
removed using sequence 100. The cross-sectional views in FIGS.
2A-2D relate to individual processing steps performed upon the film
stack. The images in FIGS. 2A-2D are not depicted to scale and are
simplified for illustrative purposes.
[0019] The sequence 100 starts at step 101 and proceeds to step 102
when a film stack 202 and etch mask 204 are formed on a wafer 200,
e.g., silicon wafer (FIG. 2A). In one embodiment, the film stack
202 comprises a barrier layer 210, a metal-containing layer 208,
and an insulating layer 206.
[0020] The barrier layer 210 and insulating layer 206 are generally
formed of a dielectric material, such as silicon nitride
(Si.sub.3N.sub.4), silicon dioxide (SiO.sub.2), hafnium dioxide
(HfO.sub.2), and the like, to a thickness of about 300 to 600
Angstroms. The metal-containing layer 208 is formed from tantalum
nitride (TaN), tantalum (Ta), titanium (Ti), tungsten (W), and the
like or compounds thereof, to a thickness of about 600 to 1000
Angstroms.
[0021] The layers of the film stack 202 can be formed using any
conventional thin film deposition technique, such as atomic layer
deposition (ALD), chemical vapor deposition (CVD), plasma enhanced
CVD (PECVD), physical vapor deposition (PVD), and the like.
Fabrication of the microelectric devices may be performed using the
respective processing reactors of CENTURA.RTM., ENDURA.RTM., and
other semiconductor wafer processing systems available from Applied
Materials, Inc. of Santa Clara, Calif.
[0022] The etch mask 204 is formed on the insulating layer 206
(FIG. 2A). The etch mask 204 protects a region 220 of the film
stack 202 while exposing adjacent regions 222 of the stack 202.
Generally, the etch mask 204 is a photoresist mask that is
fabricated using a conventional lithographic patterning process.
For such process, a photoresist layer is exposed through a
patterned mask, developed, and the undeveloped portion of the
photoresist is removed. The photoresist mask 204 typically has a
thickness of about 2000 to 6000 Angstroms.
[0023] Alternatively, the etch mask 203 may be a hard mask formed
of silicon dioxide (SiO.sub.2), Advanced Patterning Film.TM. (APF)
(available from Applied Materials, Inc. of Santa Clara, Calif.) and
hafnium dioxide (HfO.sub.2).
[0024] The etch mask 204 may further comprise an optional
anti-reflective layer 205 (shown in broken line) that controls the
reflection of the light during exposure of the photoresist. As
feature sizes are reduced, inaccuracies in an etch mask pattern
transfer process can arise from optical limitations that are
inherent to the lithographic process, such as the light reflection.
The anti-reflective layer 205 may comprise, for example, silicon
oxi-nitride, polyamides, and the like.
[0025] Processes of applying the etch mask 204 are described, for
example, in commonly assigned U.S. patent application Ser. No.
10/245,130, filed Sep. 16, 2002 (Attorney docket number 7524) and
Ser. No. 09/590,322, filed Jun. 8, 2000 (Attorney docket number
4227), which are incorporated herein by reference.
[0026] At step 104, the insulating layer 206 and the
metal-containing layer 208 are plasma etched and removed in the
unprotected regions 222 (FIG. 2B). The insulating layer 206 and the
metal-containing layer 208 may be etched using either a
chlorine-based gas mixture or, alternatively, a fluorine-based gas
mixture. The chlorine-based gas mixture may comprise chlorine
(Cl.sub.2), BCL.sub.3 and an inert diluent gas, such as at least
one of argon (Ar), helium (He), neon (Ne), and the like, along with
a small amount of a carbon-containing gas, such as carbon
tetrafluoride (CF.sub.4) and the like. Alternatively, the
fluorine-based gas mixture may comprise carbon tetrafluoride
(CF.sub.4), CHF.sub.3 or SF.sub.6 and an inert diluent gas, such as
at least one of argon (Ar), helium (He), neon (Ne), and the
like.
[0027] In one embodiment, step 104 uses the mask 204 as an etch
mask and the barrier layer 210 as an etch stop layer. Specifically,
during etching of the metal-containing film 208, the endpoint
detection system of the etch reactor may monitor plasma emissions
at a particular wavelength to determine an end of the etch process.
Conventionally, the etch process continues until a shallow recess
224 is formed in the barrier layer 210 (FIG. 2B). The shallow
recess 224 is formed to a depth 226 of not greater than about 150
Angstroms, e.g., typically about 50 to 75 Angstroms. Such recess
224 facilitates removal of the metal-containing layer 208 (e.g.,
tantalum nitride (TaN)) from the barrier layer 210 in the regions
222.
[0028] Step 104 can be performed in an etch reactor such as a
Decoupled Plasma Source (DPS) reactor of the CENTURA.RTM. system,
commercially available from Applied Materials, Inc. of Santa Clara,
Calif. The DPS reactor uses a source of radio-frequency (RF) power
at about 50 kHz to 13.56 MHz to produce a high-density inductively
coupled plasma.
[0029] During step 104, a portion of the material removed from the
insulating film 206 and the metal-containing layer 208 combine with
components of the etchant gas mixture (e.g., chlorine-containing or
fluorine-containing gases and the like), as well as with the
components of the etch mask 204 (e.g., polymeric components, and
the like) forming non-volatile compounds. Such non-volatile
compounds become re-deposited onto the substrate 200, forming a
residue 216 (i.e., post-etch residue). After the etch process, the
post-etch residue 216 is typically found on the etch mask 204,
sidewalls 212 of the film stack 202 and elsewhere on the substrate
200.
[0030] When a metal-containing layer (i.e., layer 208) is etched
during step 104, the post-etch residue 216 also comprises atoms of
such metal (e.g., tantalum (Ta), titanium (Ti), tungsten (W), and
the like) and/or compounds of the metal (i.e., metal chlorides,
metal fluorides, metal oxides, metal nitrides, and the like) that
may be formed during the etch process. In the illustrative
embodiment discussed herein, such metallic compounds may comprise
Ta.sub.xCl.sub.y (where x and y are integers), Ta.sub.xF.sub.y
(where x and y are integers), and Ta.sub.xO.sub.y (where x and y
are integers), and the like. Metal-containing post-etch residues
are generally more difficult to remove from the substrate than
other types of residue. Such residues 216 are also considered a
contaminant with respect to subsequent processing of the substrate
200.
[0031] At step 106, the etch mask 204 (e.g., photoresist mask) and
the post-etch residues 216 are removed (or stripped) from the film
stack 202 and the substrate 200 (FIG. 2C). In one embodiment, the
mask 204 and post-etch residues 216 are removed using a
hydrogen-based plasma. The hydrogen-based plasma may comprise one
or more hydrogen-containing gases including hydrogen (H.sub.2),
water vapor (H.sub.2O). The hydrogen-based plasma is preferably a
remote plasma (i.e., a plasma that is excited outside the reaction
volume of the process chamber), such as a microwave plasma excited
at about 1.0 to 10 GHz or a radio frequency plasma excited at about
0.05 to 1000 MHz.
[0032] Step 106 can be performed in a reactor such as an Advanced
Strip and Passivation (ASP) reactor of the CENTURA.RTM. system. The
ASP reactor (described in detail with reference to FIG. 3 below) is
a downstream plasma reactor in which a microwave plasma is confined
such that only reactive neutrals are provided to the reaction
volume of the process chamber. Such plasma confinement minimizes
plasma-related damage of the substrate or circuits formed on the
substrate. Alternatively, step 106 can be performed in a DPS
reactor or an AXIOM.RTM. reactor, both of which are commercially
available from Applied Materials, Inc. of Santa Clara, Calif. The
AXIOM.RTM. reactor is also a remote plasma reactor and is described
in U.S. patent application Ser. No. 10/264,664, filed Oct. 4, 2002
(Attorney docket number 6094), which is herein incorporated by
reference.
[0033] Using the CENTURA.RTM. system, upon completion of step 104,
the substrate 200 may be transported, under vacuum, from the DPS
reactor to the ASP, AXIOM.RTM. or another DPS reactor for
performing step 106. As such, the substrate is protected from
contaminants that may be present in a non-vacuumed portion of the
manufacturing environment.
[0034] In one illustrative embodiment, the etch mask 204 and
post-etch residues 216 are removed in the ASP reactor by providing
hydrogen (H.sub.2) at a flow rate of about 1000 to 5000 sccm, water
vapor (H.sub.2O) at a flow rate of up to about 50 sccm (i.e., a
H.sub.2:H.sub.2O flow ratio ranging from about 100% of H.sub.2 to
20:1), applying a microwave power of about 1000 to 2000 W at
approximately 2.45 GHz and maintaining a wafer temperature at about
100 to 300 degrees Celsius at a pressure in the process chamber of
between about 1 and 4 Torr. The duration of step 106 is generally
about 40 to 200 sec. One exemplary process provides H.sub.2 at a
rate of 3000 sccm, H.sub.2O at a rate of 30 sccm (i.e., a
H.sub.2:H.sub.2O flow ratio of about 100:1), applies a microwave
power of 1400 W and maintains a wafer temperature of 250 degrees
Celsius at a chamber pressure of 2 Torr.
[0035] Step 106 strips and volatilizes the etch mask 204 and the
post-etch residue 216. However, after step 106, traces 228 of
post-etch residues 216 and of the etch mask 204 may still remain on
the film stack 202 and substrate 200. Additionally, in some
applications, the plasma strip process of step 106 may produce a
thin film of residue 230 (shown in phantom in FIG. 2C).
[0036] At step 108, the residues 216, 230 are removed from the film
stack 202 and elsewhere on the substrate 200 (FIG. 2D). In one
embodiment, the residues 216, 230 are removed by dipping the
substrate 200 in an aqueous solution including hydrogen fluoride
(HF). In one illustrative embodiment, the aqueous solution includes
between 0.5 and 12% by volume of hydrogen fluoride. The hydrogen
fluoride solution may additionally include between 0.5 and 15% by
volume of at least one of nitric acid (HNO.sub.3) and hydrogen
chloride (HCl). After the substrate is dipped in the aqueous
solution of hydrogen fluoride, the substrate is conventionally
rinsed with deionized water to remove any traces of hydrogen
fluoride. During immersion, the aqueous hydrogen fluoride solution
may be maintained at a temperature of about 10 to 30 degrees
Celsius. The duration of the wet dip process is generally between 1
and 10 minutes. One specific process uses an aqueous solution that
comprises about 1% by volume of hydrogen fluoride, at a temperature
of about 20 degrees Celsius (i.e., room temperature), for a
duration of about 5 minutes.
[0037] At step 110, the sequence 100 ends.
[0038] The inventive method for removing residues from the
substrate uses only one wet treatment step (step 108), and such wet
treatment step is performed after the substrate is removed from a
vacuumed portion of the manufacturing environment. As a result, in
comparable applications, the sequence 100 facilitates about four
times higher throughput (measured as a number of wafers processed
in a unit of time) than conventional residue removal
techniques.
[0039] FIG. 3 depicts a schematic diagram of the exemplary Advanced
Strip and Passivation (ASP) reactor 300 that may be used to
practice portions of the invention. The ASP reactor is available
from Applied Materials, Inc. of Santa Clara, Calif. The reactor 300
comprises a process chamber 302, a remote plasma source 306, and a
controller 308.
[0040] The process chamber 302 generally is a vacuum vessel, which
includes a first portion 310 and a second portion 312. In one
embodiment, the first portion 310 comprises a substrate pedestal
304, a sidewall 316 and a vacuum pump 314. The second portion 312
comprises a lid 318 and a gas distribution plate (showerhead) 320,
which defines a gas mixing volume 322 and a reaction volume 324.
The lid 318 and sidewall 316 are generally formed from a metal
(e.g., aluminum (Al), stainless steel, and the like) and
electrically coupled to a ground reference 360.
[0041] The substrate pedestal 304 supports a substrate (wafer) 326
within the reaction volume 324. In one embodiment, the substrate
pedestal 304 may comprise a source of radiant heat, such as
gas-filled lamps 328, as well as an embedded resistive heater 330
and a conduit 332. The conduit 332 provides a gas (e.g., helium)
from a source 334 to the backside of the wafer 326 through grooves
(not shown) in the wafer support surface of the pedestal 304. The
gas facilitates heat exchange between the support pedestal 304 and
the wafer 326. The temperature of the wafer 326 may be controlled
between 20 to 400 degrees Celsius.
[0042] The vacuum pump 314 is adapted to an exhaust port 336 formed
in the bottom 316 of the process chamber 302. The vacuum pump 314
is used to maintain a desired gas pressure in the process chamber
102, as well as evacuate post-processing gases and volatile
compounds from the chamber. In one embodiment, the vacuum pump 314
comprises a throttle valve 338 to control a gas pressure in the
process chamber 302.
[0043] The process chamber 302 also includes conventional systems
for retaining and releasing the wafer 326, end of process
detection, internal diagnostics, and the like. Such systems are
collectively depicted in FIG. 3 as support systems 340.
[0044] The remote plasma source 306 includes a microwave power
source 346, a gas panel 344, and a remote plasma chamber 342. The
microwave power source 346 comprises a microwave generator 348, a
tuning assembly 350, and an applicator 352. The microwave generator
348 is generally capable of producing about 200 W to 3000 W at a
frequency of about 0.8 to 3.0 GHz. The applicator 352 is coupled to
the remote plasma chamber 342 to energize a process gas (or gas
mixture) provided to the remote plasma chamber 342 into a microwave
plasma 362.
[0045] The gas panel 344 uses a conduit 366 to deliver the process
gas to the remote plasma chamber 342. The gas panel 344 (or conduit
366) comprises means (not shown), such as mass flow controllers and
shut-off valves, to control gas pressure and flow rate for each
individual gas supplied to the chamber 342. In the microwave plasma
362, the process gas is ionized and dissociated to form reactive
species.
[0046] The reactive species are directed into the mixing volume 322
through an inlet port 368 in the lid 318. To minimize plasma damage
to devices formed on wafer 326, the ionic species of the process
gas 364 are substantially neutralized within the mixing volume 322
before the gas reaches the reaction volume 324 through a plurality
of openings 370 in the showerhead 320.
[0047] To facilitate control of the process chamber 300 as
described above, the controller 308 may be one of any form of
general-purpose computer processor that can be used in an
industrial setting for controlling various chambers and
sub-processors. The memory, or computer-readable medium, 356 of the
CPU 354 may be one or more of readily available memory such as
random access memory (RAM), read only memory (ROM), floppy disk,
hard disk, or any other form of digital storage, local or remote.
The support circuits 358 are coupled to the CPU 354 for supporting
the processor in a conventional manner. These circuits include
cache, power supplies, clock circuits, input/output circuitry and
subsystems, and the like. The inventive method is generally stored
in the memory 356 as a software routine. The software routine may
also be stored and/or executed by a second CPU (not shown) that is
remotely located from the hardware being controlled by the CPU
354.
[0048] FIG. 4 is a table 400 summarizing the process parameters of
the plasma strip process described herein using the ASP reactor.
The process parameters summarized in column 402 are for one
exemplary embodiment of the invention presented above. The process
ranges are presented in column 404. Exemplary process parameters
for the plasma strip process are presented in column 406. It should
be understood, however, that the use of a different plasma reactor
may necessitate different process parameter values and ranges.
[0049] The invention may be practiced in other semiconductor
systems wherein the processing parameters may be adjusted to
achieve acceptable characteristics by those skilled in the art by
utilizing the teachings disclosed herein without departing from the
spirit of the invention.
[0050] While the foregoing is directed to the illustrative
embodiment of the present invention, other and further embodiments
of the invention may be devised without departing from the basic
scope thereof, and the scope thereof is determined by the claims
that follow.
* * * * *