Ex Parte Rui et al

Board of Patent Appeals and Interferences

Mar 15, 2012

10446332 (B.P.A.I. Mar. 15, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
_________________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_________________

Ex parte YING RUI, CHUN YAN,
GUOWEN DING, and SUZANNE ARIAS
_________________

Appeal 2010-004483
Application 10/446,332
Technology Center 1700
_________________

Before CATHERINE Q. TIMM, KAREN M. HASTINGS, and
DEBORAH KATZ, Administrative Patent Judges.

KATZ, Administrative Patent Judge.

DECISION ON APPEAL

Appeal 2010-004483
Application 10/446,332

2
Appellants1 seek our review, under 35 U.S.C. § 134(a), of the
Examiner’s decision to reject claims 1-2, 6-9, 11-15, 18-19, 21-24, 26, 28-
29, and 32-36. (App. Br. 2.) Claims 3-5, 10, 16, 17, 20, 25, 27, 30, and 31
have been cancelled. (See Response to Office Action Dated March 26,
2008, filed June 26, 2008.) We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM the Examiner’s decision to reject the claims.
Appellants’ claims are directed to methods of removing residue from
substrates, for example, removing materials from semiconductor substrates
in the fabrication of microelectronic devices. (See Spec. ¶¶ [0001] and
[0005]-[0006].) Appellants’ claim 1 recites:
A method for removing residue from a substrate,
comprising:

etching a feature into a layer of a substrate, the step of
etching causing a metallic residue to be deposited upon the
substrate, wherein the layer comprises at least one of tantalum,
tantalum nitride, titanium, tungsten, or hafnium; and

removing the metallic residue in a single plasma step
comprising exposing the substrate to a hydrogen-based plasma
comprising hydrogen (H2) and water vapor (H2O) to volatize
the metallic residue, wherein the hydrogen-based plasma
comprises hydrogen (H2) and water vapor (H2O) at a H2:H2O
flow ratio of 20:1 or greater.

(App. Br. 15, Claims App’x.)
Appellants’ claim 29 recites:
A method for removing residue from a substrate,
comprising:

1 The real party in interest is said to be Applied Materials, Inc. (App. Br. 2.)
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Application 10/446,332

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providing a substrate having a metallic residue thereon,
the metallic residue comprising at least one of tantalum,
tantalum nitride, titanium, tungsten, or hafnium; and

exposing the substrate to a hydrogen-based plasma to
volatize the metallic residue, wherein the exposing step further
comprises providing hydrogen (H2) and water vapor (H2O) at a
H2:H2O flow ratio of 20:1 or greater.

(App. Br. 18, Claims App’x.)
The Examiner relied on the following references to reject the claims:
Graas 5,360,995 November 1, 1994
Chen ‘289 5,545,289 August 13, 1996
Kropewnicki 6,440,864 B1 August 27, 2002
Sun 2004/0018715 A1 January 29, 2004
Chen ‘942 7,320,942 B2 January 22, 2008
The Examiner also relied on Kern, “Handbook of Semiconductor
Wafer Cleaning Technology: Science, Technology, and Applications,” 124-
27 (Werner Kern ed., Noyes Publications 1993) (“HSWCT”).

The Examiner made the following rejections of the claims:
 Claims 1, 2, 29, and 32-35 under 35 U.S.C. § 102(e) over Sun
(Ans. 3);
 Claims 7-9, 11-15, 182, and 21-23 under the non-statutory doctrine of
obviousness-type double-patenting over claims 1-19 of Chen ‘942 and
Sun (Ans. 6).

2 We note that though the Examiner’s Answer included claim 17 in this
rejection, it was previously cancelled. (See Response to Office Action Dated
March 26, 2008, filed June 26, 2008.)
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Application 10/446,332

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 Claims 1, 2, 6-8, 11-15, 18, 21-23, 28-29, and 32-36 under 35 U.S.C.
§ 103(a) over Chen’289 (Ans. 3-4);
 Claims 1, 2, 6-8, 11-15, 18, 21-23, 28-29, and 32-36 under 35 U.S.C.
§ 103(a) over Kropewnicki (Ans. 4);
 Claims 24 and 26 under 35 U.S.C. § 103(a) over Chen ‘289 or
Kropewnicki, in view of Graas (Ans. 4-5); and
 Claims 9 and 19 under 35 U.S.C. § 103(a) over Chen ‘289 or
Kropewnicki, in view of HSWCT (Ans. 5-6).
Rejection under 35 U.S.C. § 102(e) over Sun
The Examiner rejected claims 1, 2, 29, and 32-35 as being anticipated
by Sun. (Ans. 3.) Sun teaches a method for removing a contaminant from
the surface of a material layer during integrated circuit fabrication. The
Examiner found Sun to teach removing residue with a hydrogen plasma
containing water. (See id., citing Sun at ¶ [0044].) The Examiner also found
that Sun teaches etching metal oxides. (See Ans. 3, citing Sun at ¶ [0037].)
In regard to claims 1 and 29, Appellants argue that Sun does not teach
the claimed flow ratio of H2:H2O of 20:1 or greater. (App. Br. 6-7; Reply
Br. 6-7 and 8-9.) According to Appellants, Sun’s teaching of a ratio of
reducing gas (H2, see Sun, ¶ [0038]) to suppressant gas (H2O, see Sun,
¶ [0039]) “in a range of about 2% to about 100%” (Sun, ¶ [0044]), is “far
removed” from the claimed ratio. (App. Br. 6.)
Appellants’ claimed range does not recite an upper limit of the ratio of
H2 to H2O, but the substrate must be exposed to both H2 and at least a
minimal amount of H2O, as water vapor. Thus, Appellants’ claimed range
begins at 20:1 and extends up to a ratio with a minimal amount of H2O, but
at least some H2O. Sun discloses a broad range of ratios of reducing gas to
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Application 10/446,332

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¶ [0037].) According to Appellants, Sun teaches only etching a feature into
the dielectric layer (304) and stopping upon reaching the underlying sub-
layer (302), but does not teach etching a feature into a metal-containing
layer. (Id.) The Examiner finds that the sub-layer (302) contains metal
oxides and is at least partially etched during the etching of the dielectric
layer (304). Thus, the Examiner finds that Sun teaches etching a feature into
a layer comprising the recited metals. (Ans. 6-7.)
The preponderance of the evidence supports the Appellants’ argument
that Sun does not teach “etching a feature” even if a minimal amount of
etching occurs in the sub-layer. Sun refers to a “feature 306” that is etched
and, thus, discriminates between incidental etching that may occur and the
purposeful etching that produces a specific shape – a “feature.” (See Sun,
¶ [0037].)
Accordingly, we reverse the Examiner’s decision to reject claims 1, 2,
29, and 32-35 as being anticipated by Sun.
Rejections under doctrine of obviousness-type double-patenting over
Chen ‘942 and Sun
The Examiner rejected claims 7-9, 11-15, 17, and 21-23 as being
rendered obvious by claims 1-9 of Chen ‘942 and Sun. (Ans. 6.) The
Examiner relied on Sun for removal of residue with a hydrogen plasma.
(Id.) Because each of the rejected claims recites “etching a feature,” and the
Examiner does not rely on Chen ‘942 to teach this feature, we reverse the
decision to reject these claims for the reasons provided above.
Rejections Under 35 U.S.C. ¶ 103(a) over Chen’289
The Examiner rejected claims 1, 2, 6-8, 11-15, 18, 21-23, 28-29 and
32-36 as being rendered obvious by Chen ’289. (Ans. 3-4.) Appellants
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Application 10/446,332

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argue for the patentability of claims 1, 13, and 33 as a group and claims 1,
13, and 29 as a group, but not any other claims. (App. Br. 8-10.) We focus
on claim 1 in our review. See 37 C.F.R. § 41.37(c)(1)(vii).
The Examiner found that Chen ‘289 teaches the claimed method
except for the concentrations of the reactants, which the Examiner concluded
one of ordinary skill in the art would have considered obvious to have
obtained by routine experimentation. (Ans. 3-4.) Appellants argue that
there is no evidence in Chen ‘289 that the ratio of H2:H2O would have been
a result effective variable, and thus would have been obvious to have
optimized. (App. Br. 9-10; Reply Br. 11-14.) Chen ‘289 teaches that the
passivating3 gas can include either hydrogen or water vapor or “mixtures
thereof.” (Chen ‘289, col. 6, ll. 63-65.) Therefore, Chen ‘289 contemplates
using pure H2, that is 100% H2, to remove etchant by products from a
surface and overlaps with the upper end of the claimed range of H2:H2O of
20:1 or greater. “In cases involving overlapping ranges, [the Federal Circuit
and the Court of Customs and Patent Appeals] have consistently held that
even a slight overlap in range[s] establishes a prima facie case of
obviousness.” In re Peterson, 315 F.3d 1325, 1329 (Fed. Cir. 2003).
Appellants have failed to direct us to evidence sufficient to persuade us that
the claimed range is critical or achieved results unexpected over those of
Chen ‘289. See In re Woodruff, 919 F.2d 1575, 1578 (Fed. Cir. 1990)
(holding that prior art teaching CO2 at 0-5% rendered obvious a claim to
“more than 5% to about 25%” CO2 where there was no sufficient showing

3 Chen ‘289 indicates that “passivation” is the removal of etchant by-
products from a surface. (See Chen ‘289, col. 1. ll. 55-57.)
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Application 10/446,332

8
that “the particular range is critical, generally by showing that the claimed
range achieves unexpected results relative to the prior art range.”).
Accordingly, we are not persuaded that the Examiner erred in relying on
Chen ‘289 for the claimed ratio of H2:H2O.
Appellants also argue that the metallic residue in claim 1 is removed
in a “single plasma step,” but that Chen ‘289 teaches a multicycle
passivation process. (See App. Br. 8; Reply Br. 10-11.) Though Chen ‘289
teaches that passivating gas can be repeatedly introduced to the substrate, it
also teaches the steps of one cycle separately. Appellants’ claim 1 recites a
method “comprising” a single plasma step, but does not exclude more steps.
(See Ans. 9.) Appellants’ claim 1 does not limit the amount of residue
removed from the substrate. Accordingly, we are not persuaded that the
teaching in Chen ‘289 to perform multiple passivation cycles is outside the
scope of Appellants’ claim.
Rejections Under 35 U.S.C. ¶ 103(a) over Kropewnicki
The Examiner rejected claims 1, 2, 6-8, 11-15, 18, 21,-23, 28-29, and
32-36 as being rendered obvious by Kropewnicki. (Ans. 4.) Appellants do
not argue for the separate patentability of any of the claims. We focus on
claim 1 in our review. See 37 C.F.R. § 41.37(c)(1)(vii).
Appellants argue that, Kropewnicki fails to teach or suggest a
hydrogen-based plasma comprising hydrogen and water vapor in the claimed
ratio, as they argued in regard to the rejection over Chen ‘289. (App. Br. 11-
12; Reply Br. 14-16.) Kropewnicki incorporates Chen ‘289 by reference
when referring to the composition of a cleaning gas. (See Kropewnicki col.
6, ll. 55-65.) Accordingly, for the reasons discussed above, the Examiner
did not err in in relying on Kropewnicki for the claimed ratio of H2:H2O.
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Application 10/446,332

9
Rejections Under 35 U.S.C. ¶ 103(a) over Chen ‘289 or Kropewnicki,
along with Graas or with HSWCT
Appellants argue that claims 24 and 26 are patentable over Chen ‘289
or Kropewnicki, along with Graas and that claims 9 and 19 are patentable
over Chen ‘289 or Kropewnicki for the same reasons they argued that claim
1 is patentable over Chen ‘289 and Kropewnicki. (See App. Br. 12-13; Reply
Br 16-17.) Because we do not find these arguments to be persuasive, for the
reasons provided above, we are not persuaded that the Examiner erred in
making these rejections.
ORDER
Upon consideration of the record and for the reasons given,
the rejection of claims 1, 2, 29, 32-35 under 35 U.S.C. § 102(e) over
Sun is not sustained;
the rejection of claims 7-9, 11-15, 18, and 21-23 under the non-
statutory doctrine of obviousness-type double-patenting over claims 1-19 of
Chen ‘942 and Sun is not sustained;
the rejection of claims 1, 2, 6-8, 11-15, 18, 21-23, 28-29, and 32-36
under 35 U.S.C. § 103(a) over Chen’ 289 is sustained;
the rejection of claims 1, 2, 6-8, 11-15, 18, 21-23, 28-29, and 32-36
under 35 U.S.C. § 103(a) over Kropewnicki is sustained;
the rejection of claims 24 and 26 under 35 U.S.C. § 103(a) over Chen
‘289 or Kropewnicki, in view of Graas is sustained; and
the rejection of claims 9 and 19 under 35 U.S.C. § 103(a) over Chen
‘289 or Kropewnicki, in view of HSWCT is sustained.
Therefore, we affirm the decision of the Examiner to reject all of the
pending claims.
Appeal 2010-004483
Application 10/446,332

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No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136.

AFFIRMED

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