Hexatech, Inc.

Patent Trials and Appeals Board

Sep 2, 2021

2020004985 (P.T.A.B. Sep. 2, 2021)

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.
15/077,057 03/22/2016 Raoul Schlesser H63978 1070US.1 (0031.6) 4374
26158 7590 09/02/2021
WOMBLE BOND DICKINSON (US) LLP
ATTN: IP DOCKETING
P.O. BOX 7037
ATLANTA, GA 30357-0037
EXAMINER
QI, HUA
ART UNIT PAPER NUMBER
1714
NOTIFICATION DATE DELIVERY MODE
09/02/2021 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.
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PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte RAOUL SCHLESSER and EDWARD A. PREBLE
Appeal 2020-004985
Application 15/077,057
Technology Center 1700

Before JEFFREY T. SMITH, JAMES C. HOUSEL, and
N. WHITNEY WILSON, Administrative Patent Judges.

HOUSEL, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1–3 and 9 under 35 U.S.C. § 103 as
unpatentable over Schowalter (US 2007/0101932 A1, pub. May 10, 2007) in
view of Morgan (US 2007/0243653 A1, pub. Oct. 18, 2007) and Moody (US
2012/0021175 A1, pub. Jan. 26, 2012). Non-Final Office Action (“Non-
Final Act.”) dated Aug. 23, 2019, at 4–9. The Examiner has withdrawn
pending claims 18–20 from consideration as directed to a non-elected
invention. Id. at 1. We have jurisdiction under 35 U.S.C. § 6(b).

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. Appellant identifies HexaTech, Inc. as the real party in
interest. Appeal Brief (“Appeal Br.”) filed Jan. 22, 2020, at 1.
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We AFFIRM.
CLAIMED SUBJECT MATTER
The invention recited in the claims on appeal relates to processes of
physical vapor transport (“PVT”) growth of single crystal aluminum nitride
(“AlN”) articles via transport of AlN source material through a temperature
gradient for deposition onto a seed crystal in a deposition zone. Specification
(“Spec.”) filed March 22, 2016, at 1:15–17.2 Appellant discloses that, in
such processes, the starting and evolving conditions of the AlN source
material is critical to the end result, such as purity, density, grain/particle
size, porosity, and thermal conductivity. Id. at 1:17–21. Appellant further
discloses that it is desirable to exclude certain polycrystalline AlN
production processes that cause crystal growth defects when used as source
material in single crystal AlN growth by PVT. Id. at 2:3–5. According to
Appellant, sintered AlN powder, which can have improved purity (e.g.,
99.9%) and higher densities (e.g., 60–72%), is inadequate for use as source
material in such PCT growth of single crystal AlN. Id. at 8–11. Appellant,
therefore, discloses processes for the preparation of polycrystalline AlN
source material including vapor, liquid, solid, and plasma growth methods,
in particular, hydride vapor phase epitaxy (“HVPE”) and physical vapor
deposition (“PVD”). Id. at 3:6–9 and 4:10–12.
Independent claims 1 and 9, reproduced below from the Claims
Appendix to the Appeal Brief, are illustrative of the claimed subject matter:
1. A process for producing a single crystal aluminum nitride
article, the process comprising physical vapor transport (PVT)

2 This Decision also cites to the Examiner’s Answer (“Ans.”) dated April 21,
2020 and the Reply Brief (“Reply Br.”) filed June 19, 2020.
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growth of the single crystal aluminum nitride article by
providing an AlN source material and an AlN seed within a
reactor in a spaced apart orientation and heating the AlN source
material in a manner sufficient to form volatilized species from
the AlN source material for transport to the AlN seed, wherein
the AlN source material is a polycrystalline hydride vapor
phase epitaxy (HVPE) grown aluminum nitride mass or a
polycrystalline physical vapor deposition (PVD) grown
aluminum nitride mass such that the source material is defined
by each of the following:
a carbon content of less than 300 ppm;
a silicon content of less than 300 ppm;
an oxygen content of less than 300 ppm;
an N/Al molar ratio of about 1;
a relative density of at least 98%;
an aluminum nitride purity of at least 99.9% by weight.
9. A process for producing an aluminum nitride (AlN)
single crystal via vapor phase transport (PVT), the process
comprising:
providing an AlN source material and an AlN seed within
a reactor in a spaced apart orientation; and
heating the AlN source material in a manner sufficient to
form volatilized species from the AlN source material for
transport to the AlN seed;
wherein the AlN source material comprises a grown
polycrystalline AlN mass that has been grown to have a
thickness of about 2.5 cm or greater, to have at least one lateral
dimension of about 3 cm or greater, to have an N/Al molar ratio
of about 1, to have a relative density of at least 98%, to have an
aluminum nitride purity of at least 99% by weight, to have a
carbon content of less than 300 ppm, to have a silicon content
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of less than 300 ppm, and to have an oxygen content of less
than 300 ppm.
OPINION
We review the appealed rejection for error based upon the issues
Appellant identifies, and in light of the arguments and evidence produced
thereon. Ex parte Frye, 94 USPQ2d 1072, 1075 (BPAI 2010) (precedential),
cited with approval in In re Jung, 637 F.3d 1356, 1365 (Fed. Cir. 2011)
(“[I]t has long been the Board’s practice to require an applicant to identify
the alleged error in the examiner’s rejections.”). After considering
Appellant’s arguments and the evidence of record, we are not persuaded of
reversible error in the stated rejection. Therefore, we affirm the Examiner’s
obviousness rejection based substantially on the fact findings, reasoning, and
conclusions set forth in the Non-Final Office Action and the Examiner’s
Answer, which we adopt as our own. We offer the following for emphasis.
The Examiner rejects claims 1–3 and 9 under 35 U.S.C. § 103 as
unpatentable over Schowalter in view of Morgan and Moody. Non-Final
Act. 4–9.
Appellant argues claims 1 and 9 together. However, Appellant does
not argue claims 2 and 3 separately. Therefore, we restrict our discussion
below to the limitations of claims 1 and 9 only; claims 2 and 3 stand or fall
with claim 1.
The Examiner finds that Schowalter teaches a process for producing a
single crystal AlN article comprising physical vapor transport (“PVT”)
growth of the article from a polycrystalline AlN source material spaced apart
from an AlN seed within a reactor, wherein the AlN source material is
heated to volatilize species therefrom for transport and deposition on the
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AlN seed. Id. at 4, 7. The Examiner further finds that Schowalter’s
polycrystalline AlN source material is high purity having an impurity
concentration of less than about 500 ppm and a density approaching
theoretical density. Id. The Examiner finds that Morgan teaches that it is
desirable to use a polycrystalline AlN source having a purity as high as
possible for growing single crystal AlN articles, such that the concentration
of oxygen and other impurities may be less than approximately 100 ppm. Id.
at 5; Morgan ¶ 49. The Examiner reasons that the concentration of any or
each impurity element in the high purity source material would be less than
about 500 ppm, and thus overlaps the recited range of less than 300 ppm. Id.
at 4. The Examinerconcludes that it would have been obvious to have
modified Schowalter’s polycrystalline AlN source material so as to have an
oxygen content as low as possible, and preferably less than 100 ppm. Id. at
5.
The Examiner further finds Schowalter teaches that HVPE may be
successfully employed to produce AlN material in the disclosed process.
Non-Final Act. 4. The Examiner concludes that it would have been obvious
to have employed HVPE in Schowalter’s process to produce the AlN
material as a known deposition method for this purpose. Id. Alternatively,
the Examiner finds that the method used to produce that polycrystalline AlN
source material is a process limitation, and Appellant has not shown that a
source material grown by HVPE or PVD is structurally distinct from
Schowalter’s source material. Id. at 6.
In addition, the Examiner finds that because Schowalter’s
polycrystalline AlN source material has a very high-purity with a density
approaching the theoretical density, the source material has an N/Al molar
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ratio of about 1. Id. at 5, 7. However, the Examiner acknowledges that
Schowalter and Morgan fail to expressly teach that the source material has a
relative density of at least 98%, an AlN purity of at least 99.9 wt.%, a
thickness of about 2.5 cm or greater, and a lateral dimension of about 3 cm
or greater. Id. For these features, the Examiner finds that Moody teaches a
polycrystalline AlN material having a thickness and diameter of at least 5
cm, a relative density of at least 98%, and a purity of at least 99.5, or as
close as possible to 100% pure. Id. at 6, 8. The Examiner concludes that it
would have been obvious to have modified Schowalter’s source material to
have the highest possible density and purity, and a thickness and diameter,
as taught by Moody in order to improve the single crystal AlN article. Id.
Appellant argues that Schowalter fails to teach a polycrystalline AlN
source material formed by HVPE. Appeal Br. 6; see also Reply Br. 2, 4.
Appellant contends Schowalter teaches that single crystal AlN articles may
be grown by sublimation/recondensation, molecular beam epitaxy (“MBE”),
or HVPE, but does not teach that the polycrystalline AlN source material
may be formed by HVPE. Appeal Br. 6. Appellant asserts that Schowalter
instead teaches reacting pure Al with pure nitrogen and using sublimation
transport to achieve near theoretical density, very high purity polycrystalline
AlN source material. Id. (citing the Declaration under 37 C.F.R. § 1.132 of
Raoul Schlesser (“Decl.”), filed May 17, 2019). Appellant urges that an
ordinary artisan would not predict that Schowalter’s AlN source material
“could be replace[d] with a polycrystalline AlN source material that is an
HVPE grown or PVD grown material.” Id. at 6–7. Appellant further asserts
that an ordinary artisan would understand that HVPE is not capable of
depositing large volumes of polycrystalline AlN material. Id. at 7 (citing the
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Decl.). Appellant further contends that the Examiner fails to point to any
teaching suggesting that an HVPE-grown or PVD-grown polycrystalline
mass is capable of exhibiting each and every one of the recited properties in
claims 1 and 9. Id. at 9–10.
Appellant’s argument is not persuasive of reversible error. To begin,
we note that Appellant fails to address the Examiner’s finding that the
recitation that the AlN source material is HPVE or PVD grown is a product-
by-process limitation. In this regard, we further note that Appellant has not
shown that a polycrystalline AlN source material grown by HPVE or PVD is
structurally different from Schowalter’s polycrystalline AlN source material.
Nor does Appellant assert that the HVPE process for growing the source
material is somehow a positive step of the process of producing single
crystal AlN articles using the HVPE grown source material.
Moreover, there is no dispute that Schowalter teaches that reacting
pure Al with pure nitrogen and using sublimation transport to achieve near
theoretical density, very high purity polycrystalline AlN source material.
Indeed, Schowalter teaches that this source material may be formed by
sublimation/recondensation. Schowalter ¶ 94. Such a process is a PVD
growth process, one of two processes recited in claim 1 for forming the
source material used in the claimed process. As such, Schowalter teaches a
PVD-grown polycrystalline AlN source material.
Alternatively, given Schowalter’s teaching that HVPE and MBE are
alternative processes to such sublimation/recondensation for growing AlN
masses, one of ordinary skill in the art would have reasonably expected that
HVPE and MBE could be used as alternative growth processes to
Schowalter’s sublimation/recondensation process for growing the
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polycrystalline AlN source material. Although, as Declarant states (Decl.
¶ 3), that Schowalter’s discussion of HVPE and MBE as alternatives to
sublimation/recondensation is directed to forming the single crystal AlN
article from the polycrystalline AlN source material, Schowalter does not
teach that HVPE and MBE cannot be used as alternative growth processes to
the sublimation/recondensation process taught for growing the source
material. In this regard, we note that Declarant fails to explain why HVPE
“is incapable of depositing large volumes of (polycrystalline) AlN material
needed for source material production.” See Decl. ¶ 4. We note that
Declarant merely states that “[p]roduction of large volumes of
polycrystalline material requires an entirely different reactor setup with
vastly different flow rates, temperatures, etc.” (id.), Declarant fails to state
that, much less explain why, such HVPE production of polycrystalline AlN
would have been outside of or was unknown to the ordinary skill in the art.
Appellant next argues that the Examiner improperly disregarded the
recited ranges for component impurities in finding that Schowalter’s
disclosed ranges overlap the recited ranges. Appeal Br. 8. Appellant notes
that Schowalter teaches that the source material has an impurity
concentration lower than 500 ppm by weight, but fails to teach that “material
may be excluded by this range.” Id. Appellant asserts that Schowalter
teaches that aluminum suboxides may be generated due to the presence of
oxygen in the source material, indicating that Schowalter’s source material
may have as much as 499 ppm oxygen (or 499 ppm silicon or 499 ppm
carbon). Id. Appellant contends that Schowalter never suggests limiting any
of oxygen, silicon, or carbon to less than 300 ppm. Id.
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This argument is not persuasive of reversible error because
Schowalter’s impurity concentration range of less than 500 ppm overlaps a
concentration range for any impurity of less than 500 ppm. In other words,
Schowalter’s range of 0–500 ppm (less than 500 ppm) overlaps claim 1’s
range of 0–300 ppm (less than 300 ppm). As the Examiner indicates, “a
prima facie case of obviousness typically exists when the ranges of a
claimed composition overlap the ranges disclosed in the prior art.” E.I.
DuPont de Nemours & Co. v. Synvina C.V., 904 F.3d 996, 1006 (Fed. Cir.
2018) (quoting In re Peterson, 315 F.3d 1325, 1329 (Fed. Cir. 2003)).
Indeed, Schowalter’s total impurity concentration range of less than 500
ppm is narrower than claim 1’s total impurity concentration range of less
than 900 ppm.
In addition, Schowalter teaches that the polycrystalline AlN source
material should have as high a purity as possible. Schowalter ¶¶ 94, 103.
Morgan teaches production of high-purity, high-density polycrystalline AlN
material, wherein sources of contaminants such as oxygen, water vapor, and
hydrocarbons are reduced to less than 10 ppb to achieve impurity
concentrations of less than 100 ppm. Morgan ¶¶ 41, 45, 49. Thus, Morgan
suggests that it is not only possible, but even desirable, to achieve impurity
concentrations of less than 100 ppm. Appellant fails to address either the
Examiner’s findings regarding Morgan or the Examiner’s reasoning for
combining the teachings of Schowalter and Morgan to achieve impurity
concentrations less than 100 ppm.
Appellant next argues that Moody has been improperly combined
with Schowalter because Moody is incapable of providing Schowalter’s
purity level (impurity concentration less than 500 ppm), much less the
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claimed purity level. Appeal Br. 10 (citing the Decl.) Appellant asserts that
Moody teaches a polycrystalline AlN material with at least 98% purity by
weight. Id. Appellant also contends that Moody’s product is sintered and
allows up to 0.5% impurities (or 5000 ppm). Reply Br. 3–4. As such,
Appellant contends that an ordinary artisan would not seek to combine
Moody with Schowalter because Schowalter teaches away from Moody’s
materials. Appeal Br. 10.
This argument is also not persuasive of reversible error because it
misapprehends the Examiner’s reliance on Moody’s teachings in the
rejection. It is well established that the obviousness inquiry does not ask
“whether the references could be physically combined but whether the
claimed inventions are rendered obvious by the teachings of the prior art as a
whole.” In re Etter, 756 F.2d 852, 859 (Fed. Cir. 1985) (en banc); see also In
re Keller, 642 F.2d 413, 425 (CCPA 1981) (stating “[t]he test for
obviousness is not whether the features of a secondary reference may be
bodily incorporated into the structure of the primary reference”). Although
the argument and the Schlesser Declaration presume that the Examiner
proposes to substitute Moody’s material for Schowalter’s in the process of
producing single crystal AlN articles, the rejection instead relies on Moody
in conjunction with Schowalter and Morgan to suggest that Schowalter’s
polycrystalline AlN source material have a density as close as possible to
theoretical density, such as at least about 98% thereof, and a purity as close
to 100% as possible, such as 99.5% (or even the 99.95% Schowalter teaches
when impurity concentration is less than 500 ppm, or even the 99.99%
Morgan teaches when impurity concentration is less than 100 ppm).
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In addition, Declarant fails to establish via persuasive technical
reasoning or sufficient supporting data that Moody is incapable of producing
an AlN source material having an oxygen content less than 300 ppm. See
Decl. ¶ 7. Declarant premises this conclusion on Moody’s disclosure that
residual impurities are mostly related to oxygen originating from surface
oxides in the starting powder. Id. However, Moody explains that choice of
particle surface area influences product purity such that greater surface area
can increase oxidation potential and oxygen content in the final product.
Moody ¶ 34. As such, Moody suggests that product purity may be controlled
by reducing particle surface area and teaches that product density can be
balanced against product purity. Id.; see also id. ¶ 42. Neither Appellant nor
Declarant directs our attention to any teaching in Moody suggesting that
product purities close to 100% and product densities of at least 98% of
theoretical density cannot be achieved.
Accordingly, we sustain the Examiner’s obviousness rejection of
claims 1–3 and 9 over the combined teachings of Schowalter, Morgan, and
Moody.
CONCLUSION
Upon consideration of the record and for the reasons set forth above
and in the Non-Final Office Action and the Examiner’s Answer, the
Examiner’s decision to reject claims 1–3 and 9 under 35 U.S.C. § 103 as
unpatentable over Schowalter in view Morgan and Moody is affirmed.
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DECISION SUMMARY
In summary:
Claim(s)
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1–3, 9 103 Schowalter, Morgan,
Moody
1–3, 9
TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(1)(iv) (2019).
AFFIRMED