Ex Parte Voutsas

Board of Patent Appeals and Interferences

Mar 30, 2005

09893866 (B.P.A.I. Mar. 30, 2005)

The opinion in support of the decision being entered today was not written for publication and
is not binding precedent of the Board.
UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte APOSTOLOS VOUTSAS
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Appeal No. 2005-0453
Application No. 09/893,866
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ON BRIEF
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Before OWENS, TIMM, and DELMENDO, Administrative Patent Judges.
TIMM, Administrative Patent Judge.
DECISION ON APPEAL
This appeal involves claims 1-23 which are all the claims pending in the application. We
have jurisdiction over the appeal pursuant to 35 U.S.C. § 134.
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INTRODUCTION
The claimed invention relates to the production of a crystallized silicon film for use in
polycrystalline thin film transistors (TFTs) of active matrix (AM) liquid crystal displays (LCDs)
(specification, p. 1, ll. 5-10). It is known in the art that silicon films enriched with a small
amount of a trace impurity, such as nickel (Ni), can be annealed more quickly than pure silicon
films due to the catalytic action of the impurity on the crystallization process (specification, p. 1,
ll. 12-16). According to the specification, introduction of the impurity into the silicon has
conventionally been accomplished using: (1) an impurity-rich liquid coating on the silicon film;
(2) an evaporated impurity layer on the silicon film; and (3) by implanting the impurity into the
silicon film (specification, p. 1, l. 16 to p. 2, l. 5). In Appellant’s process, the impurity is
introduced during a sputtering process wherein a target material including the impurity is
sputtered onto a substrate. Because the target material includes the impurity, the sputtered layer
of silicon includes the impurity incorporated therein (specification, p. 7, ll. 18-23). Claims 1 and
12 are illustrative of the invention on appeal:
1. In the fabrication of liquid crystal displays (LCDs), a method for forming silicon films
with a controlled amount of trace impurities, the method comprising:
forming a target including silicon and a first concentration of a first impurity;
supplying a substrate; and
sputter depositing a film of silicon on the substrate including a second concentration of
the first impurity.

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12. In the fabrication of liquid crystal displays (LCDs), a method for depositing silicon
films with trace impurities, the method comprising:
supplying a substrate; and
sputter depositing silicon and a controlled amount of a first impurity on the substrate.
The Examiner maintains rejections over prior art and, as evidence of unpatentability, the
Examiner relies upon the following prior art documentation:
Zhang et al. (Zhang) 5,569,936 Oct. 29, 1996
Yamazaki et al. (Yamazaki) 6,306,694 Oct. 23, 2001
Admitted prior art, specification, p. 4, line 5
The specific rejections maintained by the Examiner are as follows:
1. Claims 1-3, 12, and 14 stand rejected under 35 U.S.C. § 102(b) as being anticipated by
Zhang.
2. Claims 4, 5, 11, 13, and 15-18 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over Zhang.
3. Claims 6, 8, 9, 19, 21, and 22 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over Zhang in view of Yamazaki.
4. Claims 7, 10, 20, and 23 stand rejected under 35 U.S.C. § 103(a) as being unpatentable
over Zhang in view of Yamazaki and further in view of the Admitted Prior Art.
Appellants state that claims 1-11 stand or fall together and that claims 12-23 stand or fall
together (Brief, p. 4). It appears from the arguments that the grouping is meant to apply to the
anticipation rejection. For the anticipation rejection, therefore, we will select claims 1 and 12 to
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represent the issues on appeal. For each of the other rejections, we will select one of the rejected
claims to represent the issues on appeal.
Substantially for the reasons advanced by the Examiner in the Answer, we affirm. We
add the following primarily for emphasis.
OPINION
Anticipation by Zhang
The Examiner rejects claims 1-3, 12, and 14 under 35 U.S.C. § 102(b) as being
anticipated by Zhang. Zhang describes employing a crystallization catalyst to promote
crystallization in a silicon film. Similarly to Appellant, Zhang intends to use the crystallized
region of the silicon which contains the catalyst as a crystalline silicon TFT of an active matrix
(AM) circuit of an LCD (Zhang, abstract; col. 1, ll. 8-22). The catalyst is an “impurity” within
the meaning of Appellant’s claims (Zhang, col. 1, ll. 46-53). Zhang describes several methods
for introducing the impurity into the silicon film including a sputtering method in which the
impurity is added to the sputtering target (Zhang, col. 3, ll. 62-65).
Appellant argues that the disclosure of sputtering in Zhang neither teaches all the
elements of the invention of claims 1 and 12 nor enables one of ordinary skill in the art to
perform the process of the claims (Brief, pp. 4-6). The focus of these arguments is on the
limitations directed to the concentration of the impurity.
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The Examiner has provided sufficient reason to conclude that all the limitations of the
claimed process are present in the process of Zhang including the concentration limitations
(Answer, pp. 6-10). While not expressly articulated in the reference, the concentration
requirements of claims 1 and 12 are inherently met by the process of Zhang (Answer, pp. 7-8 and
9-10). Zhang describes forming the film by sputtering wherein the catalyst is added to the
sputtering target. Adding the catalyst to the target necessarily would result in a first
concentration of impurity in the target as required by claim 1. Performing sputtering using the
described target necessarily would result in a second concentration of impurity in the resultant
sputtered film as further required by claim 1. Moreover, the sputtering process inherently
controls the amount of the impurity on the substrate as required by claim 12 due to the inherent
rates of sputtering exhibited by silicon and the impurity.
Zhang need not expressly articulate the concentration requirements to establish a prima
facie case of anticipation, it is enough that there is a reasonable basis to conclude that the
claimed limitations are inherently met. In re Best, 562 F.2d 1252, 1254-55, 195 USPQ 430, 432-
34 (CCPA 1977). In such circumstances, it is reasonable to shift the burden to the Appellant to
prove that, in fact, the prior art sputtering process does not necessarily or inherently meet the
concentration requirements of the claims. Best, 562 F.2d at 1254, 195 USPQ at 433. Appellant
has not provided the required level of proof to overcome the reasonable conclusion of inherency.
With regard to the enablement of a reference, a reference is presumed to be enabling and
therefore, once the examiner establishes that the reference teaches each and every limitation of
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the claimed invention, the burden shifts to the applicant to prove the reference is not enabling.
Chester v. Miller, 906 F.2d 1574, 1578, 15 USPQ2d 1333, 1337 (Fed. Cir. 1990); In re Sasse,
629 F.2d 675, 681, 207 USPQ 107, 111 (CCPA 1980). Appellant provides no convincing proof
that Zhang is not enabling.
As a second matter, the Examiner further provided a reasonable basis to conclude that
one of ordinary skill in the semiconductor device forming art would have been in possession of
the claimed invention upon a reading of Zhang (Answer, p. 6-10). Zhang specifically describes
sputtering wherein the impurity is added to the target (Zhang, col. 3, ll. 62-65). As explained by
the Examiner, and further supported by Appellant’s specification, sputtering was a conventional
process in the art (Answer, p. 6-7; specification, p. 4, l. 23 to p. 7, l. 17). In such a circumstance,
Zhang need not provide an express articulation of the details of the sputtering operation to enable
one of ordinary skill to perform the operation because it is evident that those of ordinary skill in
the art possessed the knowledge. See In re Donohue, 766 F.2d 531, 533, 226 USPQ 619, 621
(Fed. Cir. 1985).
We conclude that the Examiner established a prima facie case of anticipation with
respect to the subject matter of claims 1-3, 12, and 14 which has not been sufficiently rebutted
by Appellant.
Obviousness over Zhang
The Examiner rejected claims 4, 5, 11, 13, and 15-18 under 35 U.S.C. § 103(a) as being
unpatentable over Zhang. We select claim 4 to represent the issues on appeal for this rejection.
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In the process of claim 4, the impurity is nickel (Ni) and it is present in the target in a
concentration of 0.01 to 0.5 atomic percent (at %) and present in the deposited film in a
concentration of 0.01 to 0.5 at %.
Both the Appellant and the Examiner agree that Zhang identifies nickel (Ni) as useful as
the impurity and that Zhang teaches a concentration range of 1x1017 cm-3 or more for the
resulting film (Answer, p. 3 and p. 10; Brief, pp. 6-7). The Examiner acknowledges that the
concentration of Ni in the target is not identified by Zhang (Answer, p. 10). It is the Examiner’s
position that one of ordinary skill in the art would have had the level of skill required to optimize
the concentration levels through routine experimentation to obtain the desired level of
crystallization enhancement (Answer, p. 4).
Appellant argues that the Examiner has not met the three requirements of a prima facie
case as articulated in MPEP § 2143 (Brief, pp. 7-10). In response to what the Appellant calls the
“optimization of ranges” rejection, Appellant further argues that the prior art reference must
present either a broader or alternative range of variables which, Appellant believes, is required in
such a rejection (Brief, p. 9).
We do not find Appellant’s arguments convincing. A claim is unpatentable as obvious
“if 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.” 35 U.S.C. § 103(a) (2002). Here, the “difference” relates
to the concentration levels of the Ni. Zhang describes the inclusion of Ni in the target and its
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inclusion is for the same function as disclosed by Appellant, i.e., to enhance crystallization of the
silicon film. That Zhang does not explicitly disclose the concentration level in the target is of
no matter because Zhang teaches the general conditions of the process for the same result as
Appellant. In this situation, those of ordinary skill in the art would have performed routine
experimentation to find the optimal concentration in the target that would result in the optimal
film concentration for the crystallization effect desired in the film. Further, there is no per se
requirement that the reference articulate a numerical range for the variable at issue. See In re
Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Each case should be decided on its
own facts.
Where, as here, the prior art acknowledges that the variable has effects, there is
motivation to conduct routine experimentation to optimize those effects to get the expected
benefits. There is also a reasonable expectation of success based on the known relationship
between the variable and the expected effect. It is true that a routine variable change sometimes
causes an unexpected effect. In such a situation, the claimed subject matter will be unobvious
under the law if Appellant provides evidence of an unexpected beneficial result. See In re
Boesch, 617 F.2d 272, 276, 205 USPQ 215, 219 (CCPA 1980). Note also Aller, 220 F.2d at 456,
105 USPQ at 235. No such evidence has been presented here. Appellant directs us to page 8,
lines 5-15 (Brief, p. 8), a discussion of sputtering yield, but there is no discussion there of an
unexpected result.
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We conclude that the Examiner has established a prima facie case of obviousness with
respect to the subject matter of claims 4, 5, 11, 13, and 15-18 which has not been sufficiently
rebutted by Appellant.
Obviousness over Zhang in view of Yamazaki
The Examiner rejected claims 6, 8, 9, 19, 21, and 22 under 35 U.S.C. § 103(a) as being
unpatentable over Zhang in view of Yamazaki. We select claim 8 to represent the issues on
appeal for this rejection. Claim 8 limits the impurity to germanium in a concentration of 5-30 at
% in the target and 5-30 at % in the film. The Examiner relies upon Yamazaki as evidence that
it was known in the art of TFT production to use germanium as a crystallization catalyst in
silicon films (Answer, p. 5).
Appellant argues that the Examiner has not provided a motivation to combine the Zhang
and Yamazaki references (Brief, pp. 11-12). Appellant further argues that even if the references
could be combined, there is nothing in the Yamazaki disclosure to suggest a modification of
Zhang in a way that would make the claimed invention of either claim 1 or claim 12 obvious
(Brief, p. 12).
There is a reason, suggestion, or motivation to use germanium as the catalyst in the
process of Zhang. Zhang describes using as the catalytic material “a simple substance like nickel
(Ni), iron (Fe), cobalt (Co), platinum (Pt), or compound such as silicide thereof.” (Zhang, col. 3,
ll. 50-53). The use of the word “like” indicates that the specific elements recited are merely
examples and not an exclusive list. Yamazaki indicates that, in addition to nickel, iron, and
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cobalt, other elements including germanium are useful as a catalytic element for promoting the
crystallization of an amorphous silicon film (Yamazaki, col. 7, ll. 35-42). The references
together provide a suggestion of using germanium as the catalytic impurity with a reasonable
expectation of success in obtaining the desired catalytic affect.
Nor can we agree that one of ordinary skill in the art would not have made the
modification called for by the claims. Once one of ordinary skill in the art knew that germanium
was useful as the catalyst, that person would have performed routine experimentation to find the
optimal concentration within the target which would result in the optimal film concentration, i.e.,
the film concentration which results in the desired crystallization enhancement.
We conclude that the Examiner has established a prima facie case of obviousness with
respect to the subject matter of claims 6, 8, 9, 19, 21, and 22 which has not been sufficiently
rebutted by Appellant.
Obviousness over Zhang in view of Yamazaki and the Admitted Prior Art
Claims 7, 10, 20, and 23 stand rejected under 35 U.S.C. § 103(a) as being unpatentable
over Zhang in view of Yamazaki and further in view of the Admitted Prior Art. We select claim
7 to represent the issues on appeal. Claim 7 specifies that the sputtering is performed “using a
process selected from the group including pulsed and non-pulsed direct current (DC) sputtering.”
As a first matter, the words “selected from the group including” do not limit the claim to
the recited sputtering processes. Other sputtering processes may be encompassed by the claim.
On the current record, however, the open ended nature of the claim group does not affect our
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review. That is because the Examiner has established the obviousness of using pulsed DC
sputtering in the process of Zhang. As pointed out by the Examiner, Appellant’s own
specification states that “[t]he usual type of sputtering used in commercial applications is DC
magnetron sputtering, which is limited to the sputtering of metallic target [sic].” (specification,
p. 5, ll. 3-5). We further note that the specification indicates that non-pulsed DC sputtering was
also standard (specification, p. 7, ll. 24-26).
Appellant argues that there appears to be no motivation to combine the three references
nor any reasonable expectation of success (Brief, p. 14). But Zhang specifically calls for
sputtering and, therefore, one of ordinary skill in the art would have looked to conventional
sputtering operations to perform the process of Zhang. The Examiner has provided sufficient
evidence that both pulsed and non-pulsed DC sputtering were known in the art. The express
suggestion in Zhang of using sputtering coupled with the evidence that pulsed and non-pulsed
DC sputtering were known in the art provides the required suggestion of using those sputtering
techniques in the process of Zhang with a reasonable expectation that the desired film would be
created by the process.
We conclude that the Examiner has established a prima facie case of obviousness with
respect to the subject matter of claims 7, 10, 20, and 23 which has not been sufficiently rebutted
by Appellant.
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OTHER ISSUES
Upon further prosecution, the Examiner may wish to determine whether the phrase
“process selected from the group including” in claim 7 renders claim 7 indefinite under
35 U.S.C. § 112, ¶ 2. The key question is whether the word “including” opens the group up
to other unrecited forms of sputtering such that one of ordinary skill in the art would not be
reasonably apprised of the scope of the claim. See In re Warmerdam, 33 F.3d 1354, 1361,
31 USPQ2d 1754, 1759 (Fed. Cir. 1994)(The legal standard for definiteness is whether a claim
reasonably apprises those of skill in the art of its scope.).
CONCLUSION
To summarize, the decision of the Examiner to reject claims 1-23 under 35 U.S.C.
§ 103(a) is affirmed.
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No time period for taking any subsequent action in connection with this appeal may be
extended under 37 CFR § 1.136(a).
AFFIRMED
TERRY J. OWENS )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
CATHERINE TIMM ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
ROMULO H. DELMENDO )
Administrative Patent Judge )
CT/jrg
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DAVID C. RIPMA,
PATENT COUNSEL SHARP LABORATORIES OF AMERICA
5750 NW PACIFIC RIM BLVD
CAMAS, WA 98607