Ex Parte Chen et al

Board of Patent Appeals and Interferences

Mar 24, 2010

11146309 (B.P.A.I. Mar. 24, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
_________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte CHEN-AN CHEN,
AVGERINOS GELATOS, MICHAEL X. YANG,
MING XI, and MARK M. HYTROS
__________

Appeal 2009-004394
Application 11/146,309
Technology Center 1700
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Decided: March 24, 2010
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Before ADRIENE LEPIANE HANLON, PETER F. KRATZ, and
MARK NAGUMO, Administrative Patent Judges.

HANLON, Administrative Patent Judge.

DECISION ON APPEAL

A. STATEMENT OF THE CASE
This is an appeal under 35 U.S.C. § 134 from an Examiner’s decision
rejecting claims 1-7, 9-18, 20-29, and 31-35. We have jurisdiction under
35 U.S.C. § 6(b). We REVERSE.

Appeal 2009-004394
Application 11/146,309

Claim 1, reproduced below, is representative of the subject matter on
appeal.
1. A substrate processing chamber, comprising:

a top shower plate, wherein the top shower plate has
holes in communication with a top surface and a bottom surface
of the top shower plate;

a bottom shower plate, wherein the bottom shower plate
comprises columns having column holes in communication
with a top surface and a bottom surface of the bottom shower
plate and has grooves having groove holes in communication
with the bottom surface of the bottom shower plate;

a gas box having a first gas channel;

a gas conduit coupled to the first gas channel of the gas
box, disposed through an aperture of the top shower plate, and
coupled to an aperture of the bottom shower plate, wherein the
aperture of the bottom shower plate is in communication with
the grooves of the bottom shower plate;

a substrate support;

an insulator disposed between the top shower plate and
the bottom shower plate;

a power source coupled to the top shower plate, the
bottom shower plate, or the substrate support; and

a controller adapted to control the power source to
provide pulses of power and to provide ground to the top
shower plate, the bottom shower plate, or the substrate support.

App. Br., Claims Appendix.1
The following Examiner’s rejections are before us on appeal:

1 Appeal Brief dated June 2, 2008.
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Appeal 2009-004394
Application 11/146,309

(1) Claims 1-7, 9, 11-18, 20, and 22 are rejected under 35 U.S.C.
§ 103(a) as unpatentable over the combination of Saxena2 and Lee.3
(2) Claims 10 and 21 are rejected under 35 U.S.C. § 103(a) as
unpatentable over the combination of Saxena, Lee, and Babayan.4
(3) Claims 23-29, 31, and 33 are rejected under 35 U.S.C. § 103(a)
as unpatentable over the combination of Saxena, Lee, and Raaijmakers.5
(4) Claim 32 is rejected under 35 U.S.C. § 103(a) as unpatentable
over the combination of Saxena, Lee, Raaijmakers, and Babayan.
(5) Claim 34 is rejected under 35 U.S.C. § 103(a) as unpatentable
over the combination of Saxena, Lee, and Nakano.6
(6) Claim 35 is rejected under 35 U.S.C. § 103(a) as unpatentable
over the combination of Saxena, Lee, Raaijmakers, and Nakano.
B. ISSUE
Have the Appellants identified harmful error in the Examiner’s
conclusion that it would have been obvious to one of ordinary skill in the art
to replace the top and bottom shower plates of Saxena with the top and
bottom plates of Lee to prevent undue mixing of gases and improve process
uniformity?
C. FINDINGS OF FACT
Saxena Figure 1, reproduced below, illustrates an apparatus for
chemical vapor deposition.

2 US 5,472,508 to Saxena issued December 5, 1995.
3 US 5,624,498 to Lee et al. issued April 29, 1997.
4 US 2002/0129902 A1 to Babayan et al. published September 19, 2002.
5 US 6,511,539 B1 to Raaijmakers issued January 28, 2003.
6 US 6,795,796 B2 to Nakano et al. issued September 21, 2004.
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Appeal 2009-004394
Application 11/146,309

Saxena Figure 1 depicts a chemical vapor
deposition apparatus.

The Examiner found that Saxena discloses a substrate processing
chamber 1 comprising a gas processing region defined by a top shower plate
6, a bottom shower plate 8, and a chamber wall 22 disposed between the top
shower plate 6 and the bottom shower plate 8. Ans. 3.7 The Examiner
found that the chamber wall 22 disposed between the two shower plates (6,
8) inherently functions as an insulator. Ans. 4.
The Examiner found that Saxena does not expressly teach that the
bottom shower plate 8 comprises columns having column holes in
communication with a top surface and a bottom surface of the bottom
shower plate and grooves having groove holes in communication with the
bottom surface of the bottom shower plate. Ans. 4.
The Examiner also found:

7 Examiner’s Answer dated August 18, 2008.
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Appeal 2009-004394
Application 11/146,309

Saxena does not expressly teach that the chamber comprises a
gas box having a first gas channel; and a gas conduit coupled to
the first gas channel of the gas box, disposed through an
aperture of the top shower plate, and coupled to an aperture of
the bottom shower plate, wherein the aperture of the bottom
shower plate is in communication with the grooves of the
bottom shower plate.

Ans. 4.
Lee discloses a gas supplying apparatus for evenly supplying various
gases to a reaction chamber. Lee 1:5-8.
Lee Figure 3, reproduced below, illustrates a showerhead 320 for a
gas supply method according to the disclosed invention. Lee 3:33-35.

Lee Figure 3 depicts a showerhead.
According to Lee, first and second concentric gas supply pipes 100
and 200 are connected to shower head 320, first porous plate 500 is
connected at the bottom of first gas supply pipe 100, and second porous
plate 600 is connected to the bottom of first porous plate 500. Lee 3:46-51.
Lee explains:
[T]he gases flowing via first and second gas supply pipes 100
and 200 are supplied to second porous plate 600 via two
different pathways: the first pathway being from first gas
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Appeal 2009-004394
Application 11/146,309

supply pipe 100, through first holes 300 and then through
second holes 800, and finally into the reaction chamber; and the
second pathway being from second gas supply pipe 200,
through central bore 400 and then through third holes 900, and
finally into the reaction chamber. Thus, the gas supplied via the
first and second pathways can be evenly sprayed into the
reaction chamber without being mixed with each other.
Therefore, according to the gas supply apparatus of the
present invention, gas from first and second supply pipes can be
evenly distributed in the reaction chamber, without any undue
mixing therebetween, thereby improving the uniformity of the
thin film thickness formed on a surface of a semiconductor
device during the CVD [(chemical vapor deposition)] process.

Lee 4:51-67.
The Examiner found that the structure of the first and second porous
plates (500, 600) disclosed in Lee correspond to the structure of the top and
bottom shower plates, respectively, recited in claim 1. Ans. 4-5.
D. ANALYSIS
According to the Examiner:
It would have been obvious to one of ordinary skill in the
art to modify the apparatus of Saxena to structure the top and
bottom shower plates as taught by Lee et al. The motivation for
making such a modification, as taught by Lee et al. (Column 4,
Lines 51-67), would have been to allow for the supply of two
different process gases to be evenly distributed in the reaction
chamber without mixing of the gases before delivery to the
chamber, thereby improving process uniformity.

Ans. 5.
The Examiner provides an annotated copy of Lee Figure 3,
reproduced below, illustrating the modified structure.
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Appeal 2009-004394
Application 11/146,309

Modified Lee Figure 3 depicts a showerhead.
The Appellants argue that the modified showerhead would not
provide separate pathways. App. Br. 12; Reply Br. 3.8 The Appellants
explain:
Referring to the Figure 3 of Lee modified by the
Examiner, a first gas starts from a gas supply pipe 100 to a
plenum 300, passes through holes 300 of the first porous plate
500 and enters a space between the first and second porous
plate 500, 600, then goes through either holes 800 of the second
porous plate 600 or recesses 700 and holes 900 of the second
porous plate 600; a second gas enters from a second gas pipe
200 which opens to the recesses 700 of the second porous plate
600, then either goes through the holes 900 or goes back
towards the space between the first and second porous plates
500, 600 to mix with the first gas. Therefore, both the first and
second gases have access to the space between the first and
second porous plates 500, 600, the holes 800, recesses 700, and
holes 900.

Reply Br. 3.

8 Reply Brief dated October 17, 2008.
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Appeal 2009-004394
Application 11/146,309

The Examiner contends that separating the top shower plate 500 from
the bottom shower plate 600 “would not destroy the separate pathways for
providing two different process gases.” Ans. 13. The Examiner explains:
[A] second gas can be introduced through gas conduit 200,
which passes in a sealed manner through top shower plate 500
and into bottom shower plate 600, thus delivering the second
gas to a hollow gas plenum inside bottom shower plate 600.
The second gas then diffuses through groove holes 900, which
connect the hollow gas plenum inside bottom shower plate 600
to the processing space below the shower plates. Thus,
independent gas pathways would still exist for the first and
second gases to reach the processing space without mixing,
even when the top and bottom shower plates 500, 600 are
separated from one another.

Ans. 14 (emphasis added). However, the Examiner does not identify any
structure in Lee, other than the top plate (500), which cooperates with the
bottom plate (600) to form a plenum inside the bottom plate (600).9
On this record, it is reasonable to conclude that separating the first and
second plates of Lee (500, 600), as proposed by the Examiner, would cause
gases from the first and second supply pipes (100, 200) to mix prematurely
in the space between the two plates. For this reason, one of ordinary skill in
the art would not have seen an obvious benefit to replacing the top and
bottom shower plates of Saxena with the first and second plates of Lee.
Thus, we conclude that the combined teachings of Saxena and Lee do not
render obvious the claimed subject matter.

9 The Examiner also does not explain why the gas supply pipe 200 would
remain coupled to the second plate 600 when the first and second plates
(500, 600) are separated from each other. See Appellants’ claims 1 and 23.
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Appeal 2009-004394
Application 11/146,309

The rejection of claim 23 is based on an additional reference,
Raaijmakers. However, the Examiner does not explain why Raaijmakers
cures the above-noted deficiencies of Saxena and Lee. See Ans. 8-9.
For the reasons set forth above, we cannot sustain the rejections of
claims 1-7, 9-18, 20-29, and 31-35.
E. DECISION
The decision of the Examiner is reversed.

REVERSED

tc

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