Ex Parte Keil et al

Patent Trial and Appeal Board

Mar 23, 2016

12898342 (P.T.A.B. Mar. 23, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
12/898,342 10/05/2010 Douglas Keil
119138 7590 03/25/2016
BUCHANAN INGERSOLL & ROONEY PC - LAM RESEARCH CORP
1737 KING STREET, SUITE 500
ALEXANDRIA, VA 22314
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
1015292-000507 3684
EXAMINER
MOORE, KARLA A
ART UNIT PAPER NUMBER
1716
NOTIFICATION DATE DELIVERY MODE
03/25/2016 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address( es):
ADIPDOCl@BIPC.COM
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte DOUGLAS KEIL, ERIC HUDSON, CHRIS KIMBALL, and
ANDREAS FISCHER
Appeal2014-006646
Application 12/898,342 1
Technology Center 1700
Before BRADLEY R. GARRIS, MARK NAGUMO, and
RICHARD M. LEBOVITZ, Administrative Patent Judges.
LEBOVITZ, Administrative Patent Judge.
DECISION ON APPEAL
This appeal involves claims directed to an apparatus for monitoring a
plasma process in a plasma chamber. The Examiner has finally rejected the
claims as obvious under 35 U.S.C. § 103. We have jurisdiction under 35
U.S.C. § 134. The Examiner's rejections are affirmed.
STATEMENT OF CASE
The claimed invention is an apparatus for monitoring a plasma
process in a plasma chamber which comprises a planar ion flux probe for
measuring plasma parameter data. The plasma chamber is used to make
1 "The '342 application."
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Application 12/898,342
semiconductor wafers. '342 application iii! 1, 24. According to the '342
application, "certain plasma parameters such as ion flux, plasma potential,
plasma density, electron temperature, ion species temperature, and electron-
neutral collision frequency can be associated with specific faults." Id. at
if 25. The '342 application teaches that detecting these plasma parameters
provides a method for identifying these faults and improving wafer
uniformity and consistency. Id. at iii! 25, 2.
The final rejection of claims 16-18 and 21-26 is appealed by
Appellants. Appeal Br. 2. The claims stand finally rejected by the
Examiner as follows:
1. Claims 16, 21, 22, and 24-26 under 35 U.S.C. §103(a) (pre-AIA)
as obvious in view of Klekotka2, Braithwaite3, and Klick.4
2. Claim 17 under 35 U.S.C. § 103(a) as obvious in view of Klekotka,
Braithwaite, Klick, and Hanaoka. 5
3. Claim 18 under 35 U.S.C. § 103(a) as obvious in view of Klekotka,
Braithwaite, Klick, and Hayashi. 6
4. Claim 23 under 35 U.S.C. § 103(a) as obvious in view of Klekotka,
Braithwaite, Klick, and Mitrovic. 7
Claim 16 is the only independent claim on appeal. Claim 16 is
reproduced below:
2 Klekotka, US 2004/0127031 Al published July 1, 2004.
3 Braithwaite, A Novel Electrostatic Probe Method for Ion Flux
Measurements, Plasma Source Sci. Technology, 5, 677-684 (revised 1996).
4 Klick, US 5,861,752 issued January 19, 1999.
5 Hanaoka, JP 05-136098 A published June 1, 1993.
6 Hayashi, US 2005/0092435 Al published May 1, 2005.
7 Mitrovic, US 2007/0074812 Al published April 5, 2007.
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Application 12/898,342
16. An apparatus for monitoring a plasma process
wherein a plasma process is initiated within a plasma chamber,
plasma parameter data on the plasma process is obtained by use
of a planar ion flux (PIP) probe wherein the probe is
capacitively coupled to a pulsed radio frequency (RF) source
which applies an RF burst to the probe, and wherein a sensing
surface of the probe is exposed to the plasma and is coextensive
with a component surface within the plasma chamber, and the
plasma parameter data is evaluated for indications of a fault
condition, wherein the probe is embedded in a showerhead
electrode.
REJECTION BASED ON KLEKOTKA, BRAITHWAITE, AND KLINK
Claim 16 is directed to an "apparatus for monitoring a plasma
process." The apparatus has the following elements:
(1) "a planar ion flux (PIP) probe wherein the probe is capacitively
coupled to a pulsed radio frequency (RF) source"
(2) "a sensing surface of the probe [] exposed to the plasma and []
coextensive with a component surface within the plasma chamber" and
(3) "the probe [] embedded in a showerhead electrode."
The Examiner found that Klekotka describes an apparatus for
monitoring a plasma process using (1) a probe with (2) a sensing surface
coextensive with a component surface within the plasma chamber as recited
in the rejected claims. Final Rej. 2-3. The Examiner also found that
(3) "the probe is embedded in an upper assembly part (120) which is capable
of being used as both a showerhead and/or an electrode of a capacitively
coupled set of electrodes for plasma formation." Id. at 3. The Examiner
found that Klekotka describes different types of probes for monitoring
plasma, but not a PIP probe as recited in the rejected claims. Id. However,
the Examiner found that Braithwaite teaches a PIP probe exposed to plasma
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Application 12/898,342
and co-extensive with a component surface within the plasma chamber and
capacitively coupled to a pulsed RF source. Id. The Examiner determined it
would have been obvious to one of ordinary skill in the art to have utilized a
PIP probe in Klekotka's apparatus for the probe's known advantages. Id. at
3--4.
The Examiner found that neither Klekotka nor Braithwaite describes
"provision of a PIP probe in a grounded electrode, such as the grounded
showerhead electrode of Klekotka." Id. at 4; see also id. at 3, i-f 5. However,
the Examiner found that "Klick teaches the provision of a PIP probe in an
earth/driven/grounded electrode of a plasma process apparatus for the
purpose of allowing for probe detections in a reliable and reproducible
manner" and conclude that it would have been obvious to have used it for
this purpose in Klekotka' s apparatus. Id. at 4, i-f 11.
"a sensing surface of the probe is exposed to the plasma and is coextensive
with a component surface within the plasma chamber"
Appellants contend that it would not have been obvious to have
embedded a probe in showerhead electrode and to have made its sensing
surface coextensive with the electrode's surface. Appeal Br. 6. Appellants
specifically point to Figure 1 of Klekotka said to show probe 190
"completely embedded" in upper assembly 120 and not coextensive with a
component surface. Id.
Appellants' argument is not supported by a preponderance of the
evidence.
First, Klekotka shows another probe 190 in a chamber side wall where
the probe sensing surface is shown as coextensive with the surface of the
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Application 12/898,342
wall. Klekotka, Fig. 1 ("190" on leftmost side wall). While it is true that
Klekotka's Figure 1 shows probe 190 slightly inside assembly 120, we have
not been directed to evidence that this drawing is to scale. In any event, the
Examiner reasoned that because the probe is for the purpose of measuring
plasma, it would have been obvious that it would have a sensing surface
exposed to the plasma, even if not explicitly stated or illustrated in Klekotka,
and that one obvious configuration is to place the sensing surface
coextensive with the walls as for the side wall sensing probe. Answer 12.
The concept of placing a probe exposed on the walls of a chamber is also
described in Braithwaite (Section 2.1: "probe installed ... on the side walls
of the earthed vacuum vessel") and Klick (Fig. 4, col. 9, 11. 46-56, where the
probe comprises meter electrode 21 ). Consequently, the weight of the
evidence supports the Examiner's conclusion that it would have been
obvious have configured "a sensing surface of the probe ... exposed to the
plasma and ... coextensive with a component surface within the plasma
chamber" as required by claim 16.
"the probe is embedded in a shower head electrode"
Appellants contend that there is no teaching or suggestion to embed a
PIP probe in a showerhead electrode. Appeal Br. 5---6. Appellants argue that
Braithwaite shows the probe in the wall or alongside the earth-countered
electrode. Id. at 7. Furthermore, Appellants contend:
Id.
Braithwaite states that the PIP probe must be well
separated from the counter electrode "[p ]rovided that bias and
excitation frequencies are well separated, they act
independently on the electron flux to the probe["] (see page
680, left column, 2.7).
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Application 12/898,342
Appellants make the same argument for Klick, stating that Klick' s
probe is located in a grounded wall, not in the upper electrode 3 (the location
of the electrode assembly 120 in Klekotka). Id. Appellants state that "Klick
requires the probe 20 to be in a 'wall' of the reactor to measure discharge."
Id. at 8. See Klick. col. 3, 11. 53-57; col 4, 11. 1-4; col. 5, 11. 23-30; col. 7, 11.
21-30.
We begin by clarifying the basic structure of a plasma processing
reactor. Each one of Klekotka, Braithwaite, and Klick have the same
configuration of a plasma processing reactor comprising 1) an electrode8 and
2) an RF system, parallel to the electrode, to generate the plasma. 9
In its Background section, Klick specifically teaches this
configuration:
The radio frequency alternating electric field is generated in the
plasma reactor by means of parallel-plates wherein an excited
or driven radio frequency (RF) electrode is positioned opposite
to an earth electrode. The RF electrode is also called "hot
electrode". In the following, the real electrode which
electrically forms the earth or ground, which is directly opposed
to the RF electrode and which also includes portions of the
reactor wall acting as earth, is called "earth electrode". The
electrodes of the plasma reactor are normally arranged in a
horizontal manner. The RF electrode extends close and in
parallel to the bottom wall or to the top wall of the reactor.
Klick, col. 1, 11. 31--42 (emphasis added). Thus a plasma chamber has an
electrode, which is an earth or ground electrode, and an RF electrode
8 In upper assembly 120 ofKlekotka (i-f 26; Fig. 1); upper electrode 3 of
Klick (see Fig. 3); counter electrode in Braithwaite (see Fig. 3 and Section
2.1).
9 Element 150 of Klekotka (Fig. 1, i-fi-f 19, 24); RF electrode 10 of Klick (Fig.
3, col. 6, 11. 8-10); water cooled powered electrode of Braithwaite (Fig. 3).
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opposite to it. Appellants assert that it would not have been obvious to have
positioned the PIP probe in the earth or ground electrode.
Appellants' arguments are not supported by a preponderance of
evidence.
The argument that Braithwaite requires the probe to be separated from
the counter electrode (i.e., the earth or ground electrode) is not supported by
the cited evidence. Appeal Br. 7. Appellants quoted from page 680, Section
2. 7, of Braithwaite. The full passage is as follows:
In capacitively coupled RF discharges there are fluctuations in
the RF plasma potential at the excitation frequency and its
harmonics. These are distinct from the RF bias applied to the
probe and remain after the RF bias to the probe has been
chopped off. Provided that the bias and excitationfrequencies
are well separated, they act independently on the electron flux
to the probe (see the appendix).
Braithwaite, Section 2.7 on p. 680; emphasis added.
Appellants have not adequately explained how Braithwaite' s teaching
that the RF bias frequency applied to the probe must be "well separated"
from the excitation frequency establishes that the PIP probe must be
separated from the counter earth electrode as argued by Appellants.
Appellants also state that Klick requires the probe to be in the reactor
wall. We have reviewed the passages in Klick cited by Appellants, but do
not find an express teaching that the probe is required to be in the wall of the
reactor. The cited passages (col. 3, 11. 53-57; col 4, 11. 1-4; col. 5, 11. 23-30;
col. 7, 11. 21-30) describe the probe in the reactor wall. However, we have
not been directed to a teaching that would preclude the probe from being
placed in a showerhead electrode, rather than the reactor wall.
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Application 12/898,342
Klick teaches "the radio frequency discharge current is measured in
the form of analog signals by means of the meter electrode 21 of the probe
20 at a part of reactor 2 acting as earth electrode." Klick, col. 7, 11. 21-24
(emphasis added). Thus, Klick teaches that the plasma sensing electrode
(meter electrode 21) can be part of an earth electrode. Klick also teaches
that the electrode parallel to the RF electrode is an earth electrode. Klick,
col. 1, 11. 31--42 (in Background section reproduced above). Therefore,
Klick reasonably suggests that a plasma sensing electrode could be placed in
the grounded earth electrode parallel to the RF electrode. In Klekotka, upper
assembly 120 contains the electrode parallel to the RF electrode 150.
Klekotka i-f 26, Fig. 1. The Examiner found the upper assembly 120
comprises a grounded showerhead electrode. Final Rej. 3, i-f 5. Appellants
did not challenge the Examiner's finding that the showerhead electrode is a
grounded or earth electrode. Accordingly, the Examiner's reasoning that it
would have been obvious to have put the PIP probe in the grounded
showerhead electrode of Klekotka is supported by Klick.
Nonetheless, the Examiner specifically found that Klekotka describes
a probe in an electrode parallel to the RF electrode 150. Final Rej. 2-3. The
Examiner's finding is supported by the weight of the evidence. Klekotka
teaches (emphasis added):
[0026] For example, upper assembly 120 can comprise an
electrode, an insulator ring, an antenna, a transmission line,
and/or other RF components (not shown). In addition, upper
assembly 120 can comprise permanent magnets,
electromagnets, and/or other magnet system components (not
shown). Also, upper assembly 120 can comprise supply lines,
injection devices, and/or other gas supply system components
(not shown). Furthermore, upper assembly 120 can comprise a
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Application 12/898,342
housing, a cover, sealing devices, and/or other mechanical
components (not shown).
Klekotka ,-r 26.
Upper assembly 120 is parallel to the RF electrode 150. Klekotka,
,-r 24, Fig. 1. While Klekotka does not specifically identify a shower head
electrode, the Examiner's reliance on "supply lines, injection devices, and/or
other gas supply system components (not shown)" as a teaching of the
showerhead is reasonable because a showerhead electrode is gas supply
device. Hayashi i-f 6. Even if Klekotka does not expressly say that its gas
supply system is a showerhead, a person having ordinary skill in the art
would have known that showerhead electrodes are conventionally used in
the prior art to supply gas to a plasma processing chamber (id.), and would
have recognized that Klekotka was describing a showerhead device.
For the foregoing reasons, we affirm the rejection of claim 16. Claims
21, 22, and 24--26 are not argued separately and fall with claim 16. 3 7
C.F.R. § 41.37(c)(iv).
REJECTION BASED ON HANAOKA
Claim 17 depends from claim 16, and further recites that "the PIP
probe is embedded in an outer electrode part of a multi-piece showerhead
electrode assembly." The Examiner cited Hanaoka for its teaching of a
multi-piece showerhead electrode assembly having plasma monitoring
sensors. Final Rej. 7. Appellants contend that the Examiner erred because
the sensors are not the same type of plasma sensors as required by the claim.
Appeal Br. 9-10. We do not disagree with Appellants that the claimed
sensor operates different than the sensor described by Hanaoka. However,
the rejection is based on the obviousness of using a multi-piece showerhead
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Application 12/898,342
electrode, not the specific sensor in Hanaoka. It would have been obvious to
use a prior element, such as multi-piece showerhead electrode according to
its established function. KSR Intern. Co. v. Teleflex Inc., 550 U.S. 398, 416
(2007). The rejection of claim 17 is affirmed.
REJECTION BASED ON HAYASHI
Claim 18 depends from claim 16, and further recites that the probe
comprises gas feed-though holes in a specific configuration. The Examiner
cited Hayashi for its teaching of a process monitoring device with feed holes
that meet the limitations of the claim. Final Rej. 8-9. The Examiner found
it would have been obvious to implement this structure in Klekotka,
Braithwaite, and Klick to obtain uniform gas flow and processing. Id. at 9.
Appellants contend that the Examiner erred because "Hayashi relates to
optical sensors and has nothing to do with planar PIP probes." Appeal Br.
10. Appellants state that no evidence has been provided "that an art-
recognized equivalence exists between the light transmitting windows 12, 13
of Hayashi and a PIP probe that is embedded in a showerhead electrode."
Id. This argument does not persuade us that the Examiner erred reversibly.
The rejection is based on providing holes to ensure uniformity. The
Examiner's reasoning did not require there to be equivalence in the light-
transmitting windows. Answer 16. The rejection of claim 18 is affirmed.
REJECTION BASED ON MITROVEC
Claim 23 is directed to the apparatus of claim 16, where "the probe
includes a temperature control component operable to heat or cool the
probe." The Examiner found that "Mitrovic et al. disclose the provision of a
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plasma density probe including a temperature control component for the
purpose of controlling a temperature of the probe (see, e.g. abstract, paras. 2
and 16-1 7)." Final Rej. 9. Appellants explain how Mitrovic' s probe differs
in structure from Braithwaite's PIP probe, e.g., a tube versus a disc, and
contends that the Examiner erred "by failing to explain how the cooling
mechanism described in Mitrovic can be applied to a PIP probe, for
example, how the disc and/or guard ring in the PIP probe of Braithwaite can
be cooled by circulating cooling fluid around it." Appeal Br. 12; Reply Br.
11-12.
Fig. 1 and paragraphs 17-19 of Mitrovic show a cooling system where
cooling fluid is circulated through ducts in the probe. While Appellants
argue that a disc probe is described in Braithwaite, they do not explain why
ducts underneath the disc, as reasonably suggested by Mitrovic, would not
have been expected to work to cool the probe. Appellants have the burden
to demonstrate that the prior art is art is not enabling, but have not met this
burden. The rejection of claim 23 is affirmed.
TIME PERIOD
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(l )(iv).
AFFIRMED
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