Ex Parte Brown

Board of Patent Appeals and Interferences

Mar 30, 2010

11265919 (B.P.A.I. Mar. 30, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte DALE MARIUS BROWN
____________

Appeal 2009-014839
Application 11/265,9191
Technology Center 2800
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Decided: March 30, 2010
____________

Before JOHN C. MARTIN, SCOTT R. BOALICK, and MARC S. HOFF,
Administrative Patent Judges.

BOALICK, Administrative Patent Judge.

DECISION ON APPEAL

1 Application filed November 3, 2005. The real party in interest is General
Electric Company.
Appeal 2009-014839
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2
This is an appeal under 35 U.S.C. § 134(a) from the final rejection of
claims 1-11, 13-18, 26, and 28. Claims 19-25 and 27 have been withdrawn
and claim 12 has been cancelled. We have jurisdiction under 35 U.S.C.
§ 6(b).
We affirm.

STATEMENT OF THE CASE
Appellant’s invention relates to a silicon carbide (SiC) semiconductor
device (e.g., SiC MOSFET (¶ [0003])) composed of a SiC layer and a glass
or ceramic insulating layer. (Spec. Abstract.) The thermal expansion
coefficient of the insulating layer is matched to the SiC layer to reduce
interfacial stress. (Spec. Abstract.)
Claims 1 and 7 are exemplary (minor formatting added):
1. A semiconductor device comprising:
at least one silicon carbide active device layer; and
an insulating active device layer disposed over the silicon carbide
active device layer,
wherein the insulating layer comprises glass or ceramic material.

7. A semiconductor device comprising:
a silicon carbide active device layer; and
an insulating material active device layer disposed over the silicon
carbide active device layer,
wherein a thermal expansion coefficient of the insulating material is
matched to a thermal expansion coefficient of the silicon carbide to reduce
stress at a silicon carbide active device layer-insulating material active
device layer interface, and
wherein the thermal expansion coefficient of the insulating material is
in a range of about 2 × 10-6/K to about 9 × 10-6/K.

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The prior art relied upon by the Examiner in rejecting the claims on
appeal is:
Eshita 4,994,413 Feb. 19, 1991
Frank 5,698,019 Dec. 16, 1997
Inoue2 2003/0152353 A1 Aug. 14, 2003
Claims 1-6, 18 and 26 stand rejected under 35 U.S.C. § 102(b) as
being anticipated by Eshita.
Claim 28 stands rejected under 35 U.S.C. § 103(a) as being obvious
over Eshita.
Claims 7-11 and 13-17 stand rejected under 35 U.S.C. § 103(a) as
being obvious over Eshita and Frank.

ISSUES
§ 102 Rejection - Eshita
With respect to independent claims 1 and 18, Appellant argues that
Eshita does not teach “an insulating active device layer” because “the word
‘active’ has been used to indicate that the layer participates in the device
functionality . . . [and] the recited ‘insulating active device layer’ serves as a
gate dielectric layer which is indeed ‘insulating’ but which controls the
passage of electric current between the source and the drain via electric
field.” (Br. 7.)

2 Inoue was cited by the Examiner for evidentiary purposes to illustrate that
the coefficient of thermal expansion of phosphosilicate glass (PSG) is 20 ×
10-7/K. (Ans. 9.)
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Appellant’s argument presents the following issue:
Has the Examiner erred in finding that Eshita teaches “an insulating
active device layer”?

§ 103 Rejection – Eshita/Frank
With respect to independent claim 7, Appellant argues that the
combination of Eshita and Frank does not teach or suggest all the features of
this claim because, although “Frank discloses that the thermal properties of
the glass can be changed by using additives . . . , it is well known in the art
that . . . their exact amounts is [sic] not determined merely through routine
experimentation, but rather through extensive efforts to determine suitable
properties of the glass for any particular application.” (Br. 13.)
Appellant’s argument presents the following issue:
Has the Examiner erred in finding that the combination of Eshita and
Frank teaches or suggests that “a thermal expansion coefficient of the
insulating material is matched to a thermal expansion coefficient of the
silicon carbide to reduce stress at a silicon carbide active device layer-
insulating material active device layer interface, and wherein the thermal
expansion coefficient of the insulating material is in a range of about 2 ×
10-6/K to about 9 × 10-6/K”?

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FINDINGS OF FACT
The record supports the following findings of fact (FF) by a
preponderance of the evidence.

Eshita
1. Eshita relates “to a method of manufacturing a semiconductor device
having a silicon carbide layer.” (Col. 1, ll. 9-11.) In one example,
Eshita teaches forming a MOSFET semiconductor device. (Col. 3,
ll. 51-52; figs. 4A-4E.) A layer 32 of β-phase silicon carbide is
deposited on an n-type silicon substrate 31. (Col. 3, ll. 53-54;
fig. 4A.) A source region 38 and a drain region 39 are formed in the
silicon carbide layer 32 by ion implantation. (Col. 4, ll. 26-28;
fig. 4D.) “[A] phosphosilicate glass (PSG) layer 41 is deposited on
the structure . . . as an interlayer insulator and contact holes are
provided in the PSG layer 41.” (Col. 4, ll. 32-35; fig. 4D.) An
aluminum layer 42 is deposited over the structure to form electrical
contacts for a gate electrode 37, the source region 38 and the drain
region 39. (Col. 4, ll. 38-42; fig. 4E.)

Frank
2. Frank “relates to leucite-containing phosphosilicate glass-ceramics.”
(Col. 1, ll. 4-6.) Such glass-ceramics can be used, for example, as
dental materials. (Col. 1, l. 9.) “To change . . . the thermal and
optical properties of the glass ceramics, further glasses, ceramics,
further glass-ceramics, opacifiers and/or stabilizers can also be
added.” (Col. 3, ll. 44-47.)
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Inoue
3. Inoue relates to “a planar optical waveguide device.” (¶ [0002].)
Such optical waveguide devices are formed of a phosphorus-doped
silica glass cladding layer (i.e., PSG (¶ [0029])) deposited over a
silicon substrate. (¶ [0005].) Due to the difference in the coefficient
of thermal expansion between the substrate and the cladding layer,
stresses are generated at the substrate-cladding layer interface.
(¶ [0005].) Inoue further discloses that such stresses should be
reduced. (¶ [0010]). In one embodiment, Inoue teaches depositing
PSG cladding layers 14 and 18 on a silicon substrate 12. (¶ [0031].)
The coefficient of thermal expansion for PSG is 20 × 10-7/K (i.e., 2 ×
10-6/K). (¶ [0031].)

PRINCIPLES OF LAW
Anticipation is established when a single prior art reference discloses,
expressly or under the principles of inherency, each and every limitation of
the claimed invention. Atlas Powder Co. v. IRECO, Inc., 190 F.3d 1342,
1347 (Fed. Cir. 1999); In re Paulsen, 30 F.3d 1475, 1478-79
(Fed. Cir. 1994).
“Section 103 forbids issuance of a patent when ‘the differences
between the subject matter sought to be patented and the prior art are such
that the subject matter as a whole would have been obvious at the time the
invention was made to a person having ordinary skill in the art to which said
subject matter pertains.’” KSR Int’l Co. v. Teleflex, Inc., 550 U.S. 398, 406
(2007).
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In cases involving overlapping ranges, even a slight overlap in range
establishes a prima facie case of obviousness. In re Peterson, 315 F.3d
1325, 1329 (Fed. Cir. 2003). “[T]he existence of overlapping or
encompassing ranges shifts the burden to the applicant to show that [the]
invention would not have been obvious.” Id. at 1330. Additionally, “when
the difference between the claimed invention and the prior art is the range or
value of a particular variable, then a prima facie rejection is properly
established when the difference in range or value is minor.” Haynes Int’l,
Inc. v. Jessop Steel Co., 8 F.3d 1573, 1577 n.3 (Fed. Cir. 1993). “[W]hen, as
by a recitation of ranges or otherwise, a claim covers several compositions,
the claim is anticipated if one of them is in the prior art.” Titanium Metals
Corp. v. Banner, 778 F.2d 775, 782 (Fed. Cir. 1985) (internal quotations
omited).
Where “general conditions of a claim are disclosed in the prior art, it
is not inventive to discover the optimum or workable ranges by routine
experimentation.” In re Aller, 220 F.2d 454, 456 (CCPA 1955). An
exception is where the optimized parameter was not recognized as a result-
effective variable. In re Antonie, 559 F.2d 618, 620 (CCPA 1977).
Arguments of counsel cannot take the place of factually supported
objective evidence. See, e.g., In re Huang, 100 F.3d 135, 139-40 (Fed. Cir.
1996); In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir. 1984).

ANALYSIS
We conclude that the Examiner has not erred in rejecting claims 1-6,
18 and 26 under 35 U.S.C. § 102(b). We further conclude that the Examiner
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has not erred in rejecting claims 7-11, 13-17 and 28 under 35 U.S.C.
§ 103(a).

§ 102 Rejection
We are not convinced by Appellant’s argument (Br. 7-8) that Eshita
does not teach the limitation “an insulating active device layer,” as recited in
independent claims 1 and 18.
The Examiner found that Eshita teaches all the features of claims 1
and 18. (Ans. 3; FF 1.) In particular, the Examiner found that the
phosphosilicate glass (PSG) layer 41 of Eshita corresponds to the limitation
“an insulating active device layer.” (Ans. 3.) We agree with the Examiner.
Eshita teaches that a phosphosilicate glass (PSG) layer 41, functioning
as an interlayer insulator, is deposited over a source region 38 and a drain
region 39. (FF 1.) Contact holes for the gate electrode 37, the source
region 38 and the drain region 39 are formed in the PSG layer 41 and filled
with an aluminum layer 42. (FF 1.) Thus, contrary to Appellant’s argument
that the PSG layer 41 is not “active” because it does not “participate[] in the
device functionality” (Br. 7), the PSG layer 41 functions as an insulator for
the aluminum contacts to the gate electrode 37, the source region 38 and the
drain region 39 (FF 1). Although Appellant attempts to distinguish claims 1
and 18 over Eshita by arguing that the PSG layer 41 does not control the
passage of electric current between the source and the drain (Br. 7-8), this
feature is not claimed.
Therefore, Appellant has not shown that the Examiner erred in finding
that Eshita teaches the limitation “an insulating active device layer,” as
recited in claims 1 and 18.
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We conclude that the Examiner has not erred in rejecting claims 1 and
18 under 35 U.S.C. § 102(b). Because Appellant has not presented separate
arguments regarding any of claims 2-6 and 26, we affirm the rejection of
these claims for the same reasons as for claims 1 and 18, from which they
depend.

§ 103 Rejections
Claim 28
Although Appellant nominally argues the rejection of dependent
claim 28 separately (Br. 12), the arguments presented do not point out with
particularity or explain why the limitations of this dependent claim is
separately patentable. Instead, Appellant summarily alleges that “Eshita
fails to teach or suggest the foregoing feature of independent claim 1 . . .
[and] claim [28] is believed to be clearly patentable over the cited reference
by way of this dependency and by way of additional features recited in this
claim” (Br. 12). Therefore, we will sustain the rejection of claim 28 for the
reasons discussed with respect to independent claim 1, from which claim 28
depends.

Claims 7-11 and 13-17
We are not convinced by Appellant’s argument (Br. 13) that the
combination of Eshita and Frank does not teach all the limitations of
independent claim 7. In particular, Appellant argues that the thermal
properties of the insulating material are “not determined merely through
routine experimentation, but rather through extensive efforts.” (Br. 13.)
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The Examiner acknowledged that Eshita does not teach or suggest the
limitation “wherein a thermal expansion coefficient of the insulating
material is matched to a thermal expansion coefficient of the silicon carbide
to reduce stress at a silicon carbide active device layer-insulating material
active device layer interface, and wherein the thermal expansion coefficient
of the insulating material is in a range of about 2 × 10-6/K to about 9 ×
10-6/K.” (Ans. 6.)
However, the Examiner found that “[i]t is . . . well-known in the art to
modify the thermal properties of different semiconductor layers in order [to]
minimize stress at the interface.” (Ans. 6.) The Examiner also cited Frank
for the disclosure of adjusting the thermal properties of phosphosilicate
glass-ceramics through the incorporation of additives. (Ans. 6; FF 2.) The
Examiner cited Inoue as evidence for providing a value of 2 × 10-6/K for the
coefficient of thermal expansion of PSG (Ans. 9; FF 3) and concluded that it
would have been obvious to optimize the value of thermal expansion
coefficient to “a range of about 2 × 10-6/K to about 9 × 10-6/K” to reduce
interfacial stress (Ans. 6, 9-10). We agree with the Examiner.
Eshita teaches depositing a PSG layer 41 on a silicon carbide layer 32
(FF 1) (i.e., two dissimilar materials). Inoue provides evidence that
depositing a material on a dissimilar substrate (e.g., a PSG layer 41 on a
silicon substrate 31) can result in the generation of stresses at the interface,
due to the difference in the coefficient of thermal expansion and that such
stresses should be reduced. (FF 3.) In other words, interfacial stresses can
be reduced by selecting two materials with similar coefficients of thermal
expansion. (See FF 3.) Therefore, the Examiner has not erred in finding that
Eshita, as evidenced by Inoue, teaches or suggests “a thermal expansion
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coefficient of the insulating material . . . matched to a thermal expansion
coefficient of the silicon carbide to reduce stress at a silicon carbide active
device layer-insulating material active device layer interface.”
Frank teaches that the thermal properties of PSG can be adjusted
through the incorporation of additives. (FF 2). Because Frank provides a
recognition that thermal properties are result-effective variables (i.e., thermal
properties of PSG can be adjusted via additives), optimization of such
thermal properties would have been obvious. See Antonie, 559 F.2d at 620.
In addition, to determine the optimal thermal properties for the PSG layer 41
of Eshita to reduce the generation of stresses at the interface, it would have
been obvious to include a coefficient of thermal expansion of 2 × 10-6/K,
because this value is the coefficient of thermal expansion for PSG (FF 3).
Therefore, the Examiner has not erred in finding that the combination of
Eshita and Frank teaches or suggests “wherein the thermal expansion
coefficient of the insulating material is in a range of about 2 × 10-6/K to
about 9 × 10-6/K.”
Appellant’s argument that “the cited sections of Inoue disclose, not a
range . . . but just a single value of 20 x 10-7 /K for the thermal expansion
coefficient of PSG” (Br. 14) is unconvincing because this overlapping value
of the thermal expansion coefficient is sufficient to support a conclusion of
obviousness. See Haynes Int’l, 8 F.3d at 1577 n.3. A single value falling
within a claimed range anticipates the range. Titanium Metals,, 778 F.2d at
782.
Appellant’s argument that the optimization of thermal properties are
“not determined merely through routine experimentation, but rather through
extensive efforts” (Br. 13), is also unconvincing, because no evidence has
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been provided to support this position and the arguments of counsel cannot
take the place of such evidence. See Huang, 100 F.3d at 139-40; see also De
Blauwe, 736 F.2d at 705.
We conclude that the Examiner has not erred in rejecting claim 7
under 35 U.S.C. § 103(a). Because Appellant has not presented separate
arguments regarding any of claims 8-11 and 13-17, we affirm the rejection
of these claims for the same reasons as for claim 7, from which they depend.

CONCLUSION
Based on the findings of fact and analysis above, we conclude that:
(1) the Examiner has not erred in rejecting claims 1-6, 18, and 26
under 35 U.S.C. § 102(b); and
(2) the Examiner has not erred in rejecting claims 7-11, 13-17, and 28
under 35 U.S.C. § 103(a).

DECISION
The rejection of claims 1-6, 18 and 26 under 35 U.S.C. § 102(b) is
affirmed.
The rejection of claims 7-11, 13-17 and 28 under 35 U.S.C. § 103(a)
is affirmed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED

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bim

GENERAL ELECTRIC COMPANY
GLOBAL RESEARCH
ONE RESEARCH CIRCLE
PATENT DOCKET RM., BLDG. K1-4A59
NISKAYUNA, NY 12309