Ex Parte Sun et al

Board of Patent Appeals and Interferences

Feb 22, 2010

10794704 (B.P.A.I. Feb. 22, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte BINGXI SUN,
DAVID M. PUNG,
ASHISH BODKE, and
NETY M. KRISHNA
____________

Appeal 2008-004171
Application 10/794,704
Technology Center 1700
____________

Decided: February 22, 2010
____________

Before LINDA M. GAUDETTE, KAREN M. HASTINGS, and
MICHAEL P. COLAIANNI, Administrative Patent Judges.

COLAIANNI, Administrative Patent Judge.

DECISION ON REQUEST FOR RECONSIDERATION

This is in response to a Request, filed November 23, 2009, for
reconsideration of our Decision, decided October 28, 2009, wherein we
sustained the § 103 rejection of claims 7-15 as being unpatentable over
Subrahmanyan in view of Catabay.
Appeal 2008-004171
Application 10/794,704

2
Appellants argue that the Board erred because one of ordinary
skill in the art would not have been motivated to combine the water
plasma of Catabay with the hydrogen treatment step of Subrahmanyan
(Request 2). Appellants’ arguments focus on Subrahmanyan teaching
a two step pre-cleaning process whereas Catabay teaches a single step
pre-cleaning process as not providing a reason to combine the two
steps into a single step (Request 2-4).
Specifically, Appellants argue Subrahmanyan teaches a two
step pre-cleaning process in which a resist is removed using an
oxidation step followed by a reducing treatment with hydrogen to
remove oxides whereas Catabay uses a single step resist removal
process using water plasma such that there is no teaching or
suggestion to support the Board’s decision that one of ordinary skill in
the art would have combined Catabay’s water plasma with
Subrahmanyan’s hydrogen plasma step to mitigate damage to low-K
dielectrics (Request 2). Along this vein of argument, Appellants
contend that the Board erred in its citation to column 9, line 50 to
column 10, line 6 of Subrahmanyan as showing an embodiment where
no oxygen treatment step is used (Request 4). Appellants contend that
Subrahmanyan discloses pre-cleaning “steps,” which indicates using
more than one step and that Subrahmanyan’s claims cited by the
Board as showing an embodiment where oxygen is not necessarily
present is in error because Subrahmanyan’s claim 2 recites that the
plasma includes oxygen (Request 4-5).
Contrary to Appellants’ arguments, we adhere to our analysis
that Subrahmanyan discloses that an oxygen treating step is not
Appeal 2008-004171
Application 10/794,704

3
necessarily required (Dec. 7-9). As found on pages 7 and 8 of the
Decision, Subrahmanyan discloses an example at column 9, lines 51-
63 that does not use an oxygen plasma step. Rather, Subrahmanyan’s
column 9 Example plainly discloses pre-cleaning “steps” that include
stabilizing the chamber with a hydrogen gas mixture and then
applying RF power to the coil in the chamber to clean the substrate
(Subrahmanyan, col. 9, ll. 51-63). Therefore, Appellants’ argument
that pre-cleaning “steps” somehow implies that an oxygen step is used
is contrary to the express teaching of that particular example.
As stated in the Decision (Dec. 8), our interpretation of
Subrahmanyan’s column 9 example is further supported by patentee’s
claims 1, 5, and 6, which Subrahmanyan states provide the scope of
the invention (col. 11, ll. 33-37). Subrahmanyan’s claim 1 does not
recite using an oxygen plasma step. Rather, as indicated by
Appellants (Request 4), the requirement that the plasma of claim 1 be
oxygen plasma is found in claim 2. Although claim 1 does not
exclude using oxygen plasma as argued (Request 4), interpreting
claim 1’s plasma to be oxygen plasma would render claim 2
superfluous and redundant.
Moreover, claim 6, which depends from claims 1 and 5, states
that the plasma consists of hydrogen or a mixture of hydrogen and N2,
Ar, or Ne. Plainly, claim 6, which uses the closed claim language
“consisting of” to further limit the plasma of claim 1, excludes all
other plasma gases, including oxygen. So, Subrahmanyan claims an
embodiment where hydrogen or a mixture of hydrogen and N2, Ar, or
Ne solely is used to generate the plasma of claim 1.
Appeal 2008-004171
Application 10/794,704

4
With this proper understanding of the scope of Subrahmanyan’s
invention, Appellants’ arguments regarding the incompatibility of
combining Catabay’s one step process with Subrahmanyan’s two step
process are without persuasive merit.
Appellants further argue that the Examiner’s reference to
Subrahmanyan’s citation to the Sukharev patent that teaches using
water plasma prior to removal of the copper oxide, indicates that a
two step process is required (Request 3-4). For the reasons noted
above, we find Appellant’s argument unpersuasive. Furthermore, we
stated in the footnote on page 3 of the Decision that we have not
considered the Sukharev patent in determining the propriety of the
Examiner’s rejection for the reasons noted therein (Dec. 3). We
decline the invitation to consider such evidence now.
Appellants further argue that there is no teaching to use water
plasma to remove oxides such that there is no reason to combine
Catabay’s water plasma used to remove resists with Subrahmanyan’s
hydrogen plasma step used to remove oxides (Request 2-3).
As stated on page 9 of the Decision, such an argument fails to
address the Examiner’s stated reason for using Catabay’s water
plasma as part of the hydrogen treatment step in Subrahmanyan’s
process: to remove photoresists and copper oxides in a single step and
prevent degradation to the dielectric material.
Moreover, as found on page 8 of the Decision, which
Appellants do not contest, Catabay discloses using mixtures of
hydrogen and water plasma to remove resists (Dec. 8), which provides
an additional reason for combining Catabay’s water plasma with
Appeal 2008-004171
Application 10/794,704

5
Subrahmanyan’s hydrogen plasma to simultaneously treat the
photoresists and native oxides. The teachings of the references, as a
whole, would have suggested the combination such that the
combination is not based on impermissible hindsight as argued
(Request 5). Accordingly, Appellants’ argument is not persuasive.
For the above stated reasons, we adhere to our conclusions that
Appellants have not shown reversible error in the Examiner’s § 103 rejection
of claims 7-15 over Subrahmanyan in view of Catabay.
The Request for Reconsideration is granted to the extent that
we have considered Appellants’ request, but denied to the extent that
we shall not modify our Decision.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).

DENIED

cam

PATTERSON & SHERIDAN, LLP – APPM/TX
3040 POST OAK BLVD., SUITE 1500
HOUSTON, TX 77056