Applied Materials, Inc.

Patent Trials and Appeals Board

Aug 19, 2020

15263869 - (D) (P.T.A.B. Aug. 19, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
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
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
15/263,869 09/13/2016 Soumendra Narayan BARMAN 023149USA 1935
44257 7590 08/19/2020
PATTERSON & SHERIDAN, LLP - - APPLIED MATERIALS
24 GREENWAY PLAZA
SUITE 1600
HOUSTON, TX 77046
EXAMINER
TUROCY, DAVID P
ART UNIT PAPER NUMBER
1718
NOTIFICATION DATE DELIVERY MODE
08/19/2020 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):
Pair_Eofficeaction@pattersonsheridan.com
psdocketing@pattersonsheridan.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte SOUMENDRA NARAYAN BARMAN, JIAN J. CHEN,
PRAKET P. JHA, BOK HOEN KIM, and MIGUEL S. FUNG

Appeal 2019-005594
Application 15/263,869
Technology Center 1700
____________

Before ROMULO H. DELMENDO, KAREN M. HASTINGS, and
DEBRA L. DENNETT, Administrative Patent Judges.

DELMENDO, Administrative Patent Judge.

DECISION ON APPEAL
The Appellant1 appeals under 35 U.S.C. § 134(a) from the Primary
Examiner’s final decision to reject claims 11, 12, and 16–20.2 We have
jurisdiction under 35 U.S.C. § 6(b).
We affirm.

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42—i.e., “Applied Materials, Inc.” (Application Data Sheet
filed September 13, 2016 at 6), which is also identified as the real party in
interest (Appeal Brief filed March 27, 2019 (“Appeal Br.”) at 3).
2 See Appeal Br. 6–8; Reply Brief filed July 15, 2019 (“Reply Br.”) at 2–3;
Final Office Action entered July 12, 2018 (“Final Act.”) at 3–14; Examiner’s
Answer entered May 13, 2019 (“Ans.”) at 3–14.
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I. BACKGROUND
The subject matter on appeal relates to a method for forming a silicon
nitride layer (Specification filed September 13, 2016 (“Spec.”) ¶ 2).
Representative claim 16, which was amended after final rejection to
incorporate the limitations of canceled claim 15 (Ans. 3; Appeal Br. 8), is
reproduced from the Claims Appendix to the Appeal Brief, as follows:
16. A method for forming a silicon nitride layer, comprising:
flowing a gas mixture into a processing chamber, the gas
mixture comprising trisilylamine and a nitrogen-containing
precursor other than the trisilylamine;
forming activated species of the trisilylamine and the
nitrogen-containing precursor by pulsing radio frequency power
into the processing chamber while the gas mixture is flowing into
the processing chamber at a chamber pressure ranging from
about 1 mtorr to about 15 mtorr, wherein the radio frequency
power has a power ranging from about 25 W to about 300 W, the
pulsed radio frequency power having a duty cycle ranging from
about 5 percent to about 30 percent; and
reacting the activated species of the trisilylamine and the
nitrogen-containing precursor to form a reaction product on a
substrate disposed in the processing chamber, the substrate
having a temperature of less than 300 degrees Celsius.
(Appeal Br. 10 (emphasis added)).
II. REJECTION ON APPEAL
Claims 11, 12, and 16–20 stand rejected under 35 U.S.C. § 103 as
unpatentable over Lee et al.3 (“Lee”) in view of Hausmann et al.4

3 US 2010/0184302 A1, published July 22, 2010.
4 US 2010/0099271 A1, published April 22, 2010.
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(“Hausmann ’271”) and further in view of Hausmann et al.5 (“Hausmann
’854”).
III. DISCUSSION
1. Grouping of Claims
Although the Appellant provides arguments under a separate sub-
heading for claim 15, which has been canceled and incorporated into
independent claim 16 (Appeal Br. 8), claims 11, 12, and 16–20 are argued
together (id. at 6–7). Therefore, we decide this appeal on the basis of
independent claim 16, which we designate as representative pursuant to 37
C.F.R. § 41.37(c)(1)(iv). By this rule, claims 11, 12, and 17–20 stand or fall
with claim 16.
2. The Examiner’s Position
The Examiner finds that Lee describes a method for forming a
conformal silicon nitride layer on a semiconductor substrate comprising the
same steps recited in claim 16 except Lee does not disclose pulsing the
plasma power to about 25 W to about 300 W (Ans. 3–4, 6–8). Regarding
pulsing the power, the Examiner finds that Hausmann ’271 teaches pulsing
the plasma power in a PECVD (plasma enhanced chemical vapor
deposition) process to achieve enhanced control—i.e., more control to form
silicon-based dielectric films that are thinner and more conformal than those
produced by conventional PECVD, efficiency, and product quality (id. at 4–
5). Based on Hausmann ’271’s teachings, the Examiner concludes that
it would have been obvious to a person having ordinary skill in
the art before the effective filing date of the claimed invention to
have modified the process of Lee to have pulsed the RF [radio

5 US 2013/0189854 A1, published July 25, 2013.
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frequency] plasma power during the deposition of the silicon
nitride film because Hausmann ’271 teaches that it will provide
enhanced control, efficiency and product quality of the PECVD
process to form thinner and more conformal films such that it
will provide the desired and predictable result of depositing
improved silicon nitride films.
(Id. at 5). Regarding the power wattage, the Examiner finds that Hausmann
’854 teaches that suitable plasma power wattages in a silicon nitride
deposition process using trisilylamine (TSA) as a silicon-containing
precursor and a nitrogen-containing reactant may range from 100 W to 5,000
W (id. at 8). Based on Hausmann ’854’s teachings, the Examiner concludes
that
it would have been obvious to a person having ordinary skill in
the art before the effective filing date of the claimed invention to
have modified the method of Lee in view of Hausmann ’271 to
have selected a plasma power ranging from 100 to 5000 W
because Hausmann ’854 teaches that such a power is suitable for
generating a plasma used to activate a vapor phase reaction
involving TSA and a nitrogen-containing reactant such as
ammonia such that it will provide the desired and predictable
result of providing suitable power to generate a plasma from the
processing gas as indicated by Hausmann ’854.
(Id. at 8–9).
3. The Appellant’s Contentions
The Appellant contends that a person having ordinary skill in the art
would not have combined Lee, which teaches TSA, with Hausmann ’271,
because Hausmann ’271 does not disclose TSA as a silicon-containing
precursor and, therefore, does not teach or suggest using pulsed plasma with
TSA (Appeal Br. 6). According to the Appellant, Hausmann ’271 teaches
using pulsed plasma power to solve a specific problem for radicals having
“high sticking coefficients,” but activated species of TSA are described in
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the current Specification as having “lower sticking coefficients” (id.). The
Appellant urges that, therefore, these references “do not teach, show, or
suggest a method including forming activated species of the trisilylamine
and the nitrogen-containing precursor by pulsing radio frequency power into
the processing chamber while the gas mixture is flowing into the processing
chamber, as recited in claim 16” (id. at 7). Regarding Hausmann ’854, the
Appellant argues that it does not cure the alleged deficiencies in the
Examiner’s combination of Lee and Hausmann ’271, and further that, in
Hausmann ’854, “a plasma is struck only when the flow [of] TSA reactant is
ceased” (id. at 8). The Appellant urges that, therefore, Hausmann ’854
“does not teach a method including forming activated species of the
trisilylamine and the nitrogen-containing precursor by pulsing radio
frequency power into the processing chamber while the gas mixture is
flowing into the processing chamber” (id.).
4. Opinion
For the reasons well-stated in the Examiner’s Answer and Final
Action, we conclude that the Appellant’s arguments fail to identify
reversible error in the rejection.6 We add the following for emphasis.
As the Examiner correctly finds, Lee describes a method for forming a
conformal dielectric film having Si–N bonds on a semiconductor substrate
by PECVD, wherein the method includes the steps of: introducing a
nitrogen- and hydrogen-containing reactive gas and an additive gas into a
reaction space in which a semiconductor substrate is placed; applying RF
power to the reaction space maintained at pressures and temperatures that

6 See, e.g., In re Jung, 637 F.3d 1356, 1365 (Fed. Cir. 2011).
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overlap those recited in claim 16; and introducing a hydrogen-containing
silicon precursor (e.g., TSA) in pulses into the reaction space in which
plasma is excited, thereby forming a conformal dielectric film having Si–N
bonds on the substrate (Lee ¶¶ 10–11, 20, 35–36; Abstract; Fig. 2b).
Although Lee does not disclose pulsing the plasma power to about 25 W to
about 300 W, as recited in claim 16, we agree with the Examiner that
Hausmann ’271 and Hausmann ’854 bridge this gap.
Specifically, as the Examiner correctly finds, Hausmann ’271 teaches
that when the plasma power is pulsed in a PECVD method for forming a
silicon-based dielectric film on a semiconductor substrate, control,
efficiency, and product quality are enhanced (Hausmann ’271 Abstract).
According to Hausmann ’271, pulsing the plasma power provides “a more
controllable deposition” and “allows for the production of thin films and
films with good conformability (or step coverage) in a single pulsed plasma
deposition process operation” (id. ¶ 3; see also id. ¶ 20). Hausmann ’271
teaches that, “[f]or example, pulsing the high frequency RF plasma power at
500 Hz with a 15% duty cycle dramatically improves the step coverage and
decreases the thickness per deposition time for silane-based PECVD films”
(id. ¶ 35). Although Hausmann ’271 appears to teach that pulsed power may
be used for radicals that “are highly reactive with high sticking coefficients”
(id. ¶ 34), it does not say that activated TSA species have “high sticking
coefficients” or that pulsed power would be unsuitable for TSA—activated
species of which are characterized in the current Specification as having
“lower sticking coefficients” (Spec. ¶ 22). In this regard, we agree with the
Examiner (Ans. 12) that the phrase “lower sticking coefficients” is not
quantifiable because no standard is provided to determine what would be
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considered “lower”—let alone relative to “high sticking coefficients”
mentioned in Hausmann ’271. In any event, Hausmann ’271 explicitly
teaches that pulsed power is suitable for “generally the same precursors as
used in PECVD performed without pulsing the high frequency RF power
(i.e., conventional PECVD)” (Hausmann ’271 ¶ 29), which would include
silicon-containing precursors such as TSA. Hence, we discern no reversible
error in the Examiner’s well-articulated reason for combining Lee and
Hausmann ’271—i.e., that a person having ordinary skill in the art would
have been prompted to implement Hausmann ’271’s pulsed plasma power,
while maintaining the gas flows (id. ¶¶ 42–44), in Lee’s method with a
reasonable expectation of achieving “a more controllable deposition” and
producing “thin films and films with good conformability (or step coverage)
in a single pulsed plasma deposition process operation” (id. ¶ 3). KSR Int’l
Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007) (“[I]f a technique has been
used to improve one device, and a person of ordinary skill in the art would
recognize that it would improve similar devices in the same way, using the
technique is obvious unless its actual application is beyond his or her
skill.”).
As for the pulse power, we are not persuaded by the Appellant’s
attack on Hausmann ’854 for the same reasons as stated in the Examiner’s
Response to Argument section (Ans. 13). Moreover, as the Examiner
correctly finds (id.), Hausmann ’271, for example, would have suggested
that the power wattage is a result-effective variable that controls whether a
suitable plasma is generated (Hausmann ’271 ¶ 40 (“The power and
frequency supplied by matching network 506 is sufficient to generate a
plasma from the process gas, for example 400-700 W total power.”)). Thus,
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although Hausmann ’271 provides only an exemplary power range of 400–
700 W, a person having ordinary skill in the art would have determined—
through nothing more than routine experimentation—the full range of
suitable wattages, including those within the range recited in claim 16, that
would generate a suitable pulsed plasma. In re Applied Materials, Inc., 692
F.3d 1289, 1295 (Fed. Cir. 2012).
Accordingly, we uphold the Examiner’s rejection.

IV. CONCLUSION
In summary:
Claims
Rejected
35 U.S.C. §  Reference(s)/Basis Affirmed Reversed
11, 12,
16–20
103  Lee, Hausmann ’271,
Hausmann ’854
11, 12, 16–20

No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).

AFFIRMED