Ex parte Law et al.

Board of Patent Appeals and Interferences

Nov 28, 2001

08303566 (B.P.A.I. Nov. 28, 2001)

The opinion in support of the decision being entered today was not written for publication and
is not binding precedent of the Board.
Paper No. 45
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte KAM S. LAW,
ROBERT ROBERTSON,
PAMELA LOU,
MARC M. KOLLRACK,
ANGELA LEE,
and
DAN MAYDAN
____________
Appeal No. 1997-3514
Application No. 08/303,566
____________
HEARD: OCTOBER 23, 2001
____________
Before WARREN, TIMM, and DELMENDO, Administrative Patent Judges.
TIMM, Administrative Patent Judge.
DECISION ON APPEAL
Applicants’ appeal the decision of the Primary Examiner finally rejecting claims 1-13, which are
all of the claims pending in this application. We have jurisdiction under
35 U.S.C. § 134.
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Application No. 08/303,566
We note that claim 1 was incorrectly reproduced in the Appendix to the Brief. Therefore, we1
reproduce the claim as set forth in the Response under 37 CFR § 1.115 filed, according to the
certification of mailing, on May 6, 1996 (Paper No. 31) as further amended by the Response under 37
CFR § 1.116 filed, according to the certificate of mailing, on October 9, 1996 (Paper No. 34) entered
as per the Advisory Action mailed November 4, 1996 (Paper No. 35).
THE INVENTION
According to Appellants, the invention relates to a process of depositing amorphous silicon
onto a glass substrate by plasma chemical vapor deposition (plasma CVD) (specification, page 1, lines
5-9). The process is conducted at specific pressures and temperatures in a variable spacing CVD
reactor. Appellants indicate that the use of those pressures and temperatures in the specified reactor
results in deposition rates of about 500-3000 angstroms per minute, rates which are said to be an order
of magnitude higher than prior art processes (specification, page 9, lines 2-8). Claim 1 is illustrative of
the process on appeal:1
1. A plasma chemical vapor deposition process comprising depositing an amorphous
silicon layer from a precursor gas mixture of silane and hydrogen onto a glass substrate at a
temperature in a range of about 270-350 C and a pressure of at least about 0.8 torr in ao
vacuum chamber while maintaining a spacing between the gas inlet mainfold and the substrate
so that the silicon deposition rate is optimized.
THE EVIDENCE
As evidence of unpatentability, the Examiner relies upon the following prior art
references:
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Application No. 08/303,566
Dohjo et al. (Dohjo) 4,905,066 Feb. 27, 1990
Hey et al. (Hey) 4,987,856 Jan. 29, 1991
Iwamoto et al. (Iwamoto) 5,258,207 Nov. 02, 1993
Yamagishi et al. (Yamagishi) 5,264,710 Nov. 23, 1993
Kenmotsu et al. (Kenmotsu) 62-136870 Jun. 19, 1987
(published Japanese Patent Application)
THE REJECTIONS
Claims 1, 3, and 5 stand rejected under 35 U.S.C. § 103 as being unpatentable over
Yamagishi in view of Hey and Iwamoto. These three references serve as the foundation for the
rejection of all the other claims. To reject claim 6, the Examiner further adds Kenmotsu. Dohjo is
added to reject claims 7-9, 12, and 13. Both Kenmotsu and Dohjo are added to reject claims 10 and
11. We reverse all the rejections because the Examiner has failed to establish that the combination of
Yamagishi, Hey, and Iwamoto, the references used to reject independent claim 1, would have led one
of ordinary skill in the art to perform the process using a pressure and temperature within the ranges
required by that claim.
OPINION
The Examiner states that Yamagishi describes, in Examples 1-3, a plasma CVD process for
forming amorphous silicon films on a glass substrate heated to 200EC using silane at a pressure range of
0.4 to 3 Torr (Answer, page 3). We note that Examples 1 and 2 specify a pressure of 3 Torr. This
pressure is at least about 0.8 Torr as required by claim 1. However, the 200EC temperature specified
Appeal No. 1997-3514 Page 4
Application No. 08/303,566
in all of the Examples of Yamagishi is not within the 270-350EC range required by the process of claim
1. The Examiner fails to note this temperature difference in the rejection (Answer, page 3).
The secondary references do not describe a plasma CVD process in which the substrate is
heated to a temperature of 270-350EC. Hey is included in the rejection for its description of a plasma
CVD apparatus and this reference contains no discussion of the temperature and pressure requirements
of plasma CVD. Iwamoto describes a plasma CVD process, but specifically limits the substrate
temperature to a level below 100EC (col. 1, lines 63-67).
Furthermore, as evidenced by the combination of Yamagishi and Iwamoto, one of ordinary skill
in the art would have been led to heat the substrate to a temperature lower than that required in the
claimed process. The Examiner rationalizes that one of ordinary skill in the art would have recognized
from Iwamoto that using a higher substrate temperature and higher pressure would have resulted in a
higher deposition rate (Answer, pages 9 and 10). The problem with this conclusion is that both
Iwamoto and Yamagishi are concerned with producing amorphous silicon films with high photoelectric
conductivity and photo-semiconductors made therefrom (Iwamoto, col. 1, lines 12-17; Yamagishi, col.
1, lines 11-33). Iwamoto specifically indicates that high photoelectric conductivity is only possible
when the substrate is held at a temperature below 100EC. The combination of Yamagishi with
Iwamoto would have led one of ordinary skill in the art to heat the glass substrate to a temperature
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Application No. 08/303,566
lower than 270-350EC to obtain the high photoelectric conductivity required for the photo-
semiconductor applications envisioned by both references.
Because the Examiner failed to provide any evidence or convincing rationale that one of
ordinary skill in the art would have found it obvious to conduct the process at the combination of
temperatures and pressures required by claim 1, the independent claim, we conclude that the Examiner
has failed to establish a prima facie case of obviousness with respect to the subject matter of claim 1
and claims 2-13 which depend therefrom. We note that neither Kenmotsu nor Dohjo, as relied on by
the Examiner to reject the various dependent claims, fill the evidentiary gap.
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Application No. 08/303,566
CONCLUSION
To summarize, the decision of the Examiner to reject claims 1-13 under 35 U.S.C. § 103 is
reversed.
REVERSED
CHARLES F. WARREN )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
CATHERINE TIMM ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
ROMULO H. DELMENDO )
Administrative Patent Judge )
CT:hh
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Application No. 08/303,566
Patent Counsel
Applied Materials, Inc.
P.O. Box 450 A
Santa Clara, CA 95052