Ex Parte Tanaka

Board of Patent Appeals and Interferences

Jan 23, 2008

09842797 (B.P.A.I. Jan. 23, 2008)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte KOICHIRO TANAKA
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Appeal 2007-0832
Application 09/842,797
Technology Center 2800
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Decided: January 23, 2008
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Before ANITA PELLMAN GROSS, ROBERT E. NAPPI,
and MARC S. HOFF, Administrative Patent Judges.

GROSS, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE
Tanaka (Appellant) appeals under 35 U.S.C. § 134 from the
Examiner's Final Rejection of claims 1 through 30. We have jurisdiction
under 35 U.S.C. § 6(b).
Appellant's invention relates generally to a method of making a
semiconductor device. The method includes forming a first and a second
crystalline region by irradiating a semiconductor film with a laser beam.
The laser beam is moved in a first direction for irradiating the first region
Appeal 2007-0832
Application 09/842,797

and in a direction parallel to the first direction for irradiating the second
region. The first region overlaps only a portion of the second region along
the first direction. Claim 1 is illustrative of the claimed invention, and it
reads as follows:
1. A method of fabricating a semiconductor device comprising the
steps of:

forming an amorphous semiconductor film having an upper surface;

forming a first crystalline region by irradiating a laser beam to a first
region of the upper surface of the amorphous semiconductor film by
relatively moving the laser beam in a first direction with respect to the first
region of the amorphous semiconductor film; and

after forming the first crystalline region, forming a second crystalline
region by irradiating the laser beam to a second region of the upper surface
of the amorphous semiconductor film including a portion of the first
crystalline region by relatively moving the laser beam in a direction parallel
to the first direction with respect to the second region of the amorphous
semiconductor film;

wherein:

a wavelength of the laser beam falls in a range of 370 nm through
650 nm,

the first region of the upper surface of the semiconductor film
overlaps with only a portion of the second region of the upper surface along
the first direction.

The prior art references of record relied upon by the Examiner in
rejecting the appealed claims are:
Yamazaki (Yamazaki I) US 5,365,080 Nov. 15, 1994
Yamazaki (Yamazaki II) US 5,893,730 Apr. 13, 1999

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Application 09/842,797

G. Andra, Laser Induced Crystallization: A Method For Preparing Silicon
Thin Film Solar Cells, IEEE, 639-42 (1997).

Claims 1 through 18 and 25 through 30 stand rejected under 35 U.S.C.
§ 103 as being unpatentable over Yamazaki I in view of Andra and
Appellant's Admitted Prior Art.
Claims 19 through 24 stand rejected under 35 U.S.C. § 103 as being
unpatentable over Yamazaki I in view of Andra, Appellant's Admitted Prior
Art, and Yamazaki II.
We refer to the Examiner's Answer (mailed June 13, 2006) and to
Appellant's Brief (filed March 28, 2006) and Reply Brief (filed August 11,
2006) for the respective arguments.

SUMMARY OF DECISION
As a consequence of our review, we will reverse the obviousness
rejections of claims 1 through 30.

OPINION
Appellant contends (Br. 2-3) that Yamazaki I, Andra, and the
admitted prior art do not teach or suggest forming two crystalline regions
using the same laser beam, as recited in each of independent claims 1
through 6. Further, Appellant contends (Br. 3-4) that Yamazaki I, Andra,
and the admitted prior art do not teach or suggest a first region overlapping
only a portion of a second region along the direction in which the laser beam
moves, as recited in each of independent claims 1 through 6.
The Examiner asserts (Ans. 6) that Yamazaki I discloses forming the
two crystalline regions using the same laser beam, but using different pulse
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Application 09/842,797

durations. Further, the Examiner asserts (Ans. 7) that Appellant's admitted
prior art Figures 4(A)-4(C) show the first region overlapping only a portion
of the second region "in a first direction." Accordingly, the issues are
whether the combination of references teaches or suggests: 1) using the same
laser to form two crystalline regions and 2) overlapping the first region with
only a portion of the second region along the direction in which the laser
beam moves.
As to the first issue, Yamazaki I discloses (col. 4, ll. 51-57) that the
two laser annealing steps are accomplished using different wavelengths of
laser radiation "or different pulse durations of pulsed laser." Thus, although
we agree with Appellant that the majority of Yamazaki I's disclosure, and
particularly Yamazaki I's examples, suggests using two different lasers,
Yamazaki I expressly discloses that an alternative is to make the two pulse
durations different.
Regarding the second issue, Figure 4(A) of the admitted prior art
shows irradiating in the horizontal direction, but a partial overlap of the two
regions in the vertical direction. Thus, the partial overlap is not along the
direction in which the laser beam moves. In the horizontal direction, the
direction in which the laser beam moves, the overlap between the two
regions extends across the entire second region. None of the admitted prior
art shows the overlap between the two regions in the same direction as the
movement of the laser. Further, Yamazaki I discloses region one
overlapping all of region two rather than only a portion thereof, and Andra
does not discuss an overlap of two regions. Therefore, since none of the
prior art applied against the claims discloses or suggests overlapping the two
regions in the direction in which the laser moves, the combination likewise
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Application 09/842,797

cannot teach or suggest the claimed overlap. Accordingly, we cannot sustain
the obviousness rejection of independent claims 1 through 6 nor of their
dependents, claims 7 through 18 and 25 through 30.
Regarding claims 19 through 24, the Examiner (Ans. 5) adds
Yamazaki II to the primary combination to show that semiconductor devices
are used in video cameras, personal computers, etc. Yamazaki II, however,
fails to cure the deficiencies of Yamazaki I, Andra, and the admitted prior
art. Therefore, we cannot sustain the obviousness rejection of claims 19
through 24.

ORDER
The decision of the Examiner rejecting claims 1 through 30 under
35 U.S.C. § 103 is reversed.
REVERSED

Tdl/gw

FISH & RICHARDSON P.C.
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