Ex parte Dauksher et al.

Board of Patent Appeals and Interferences

Sep 28, 2001

08740402 (B.P.A.I. Sep. 28, 2001)

The opinion in support of the decision being entered today was not written
for publication and is not binding precedent of the Board.
Paper No. 11
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte WILLIAM J. DAUKSHER and DOUGLAS J. RESNICK
____________
Appeal No. 1998-2329
Application No. 08/740,402
____________
ON BRIEF
____________
Before PAK, OWENS, and WALTZ, Administrative Patent Judges.
WALTZ, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on an appeal under 35 U.S.C. § 134 from
the examiner’s final rejection of claims 1 through 9 and 19.
Claims 10 through 18 are the only other claims pending in this
application but remain withdrawn from consideration by the
examiner as being directed to a non-elected invention (Final
Rejection dated Sep. 3, 1997, Paper No. 4, page 2).
According to appellants, the invention is directed to a
method of forming a low stress, hard mask for use in refractory
Appeal No. 1998-2329
Application No. 08/740,402
For judicial economy, we have combined the examiner’s1
rejections since they involve the same references and issues.
In fact, the examiner had only made two rejections under
section 103(a) in the Final Rejection (Paper No. , pages 3 and
5) but expanded these rejections into six rejections in the
Answer.
2
radiation mask fabrication where depositing an oxynitride as a
hard mask layer has been found to produce stresses low enough to
come within the range specified in the claims (Brief, page 4).
A copy of illustrative claim 1 is attached as an Appendix to
this decision.
The examiner has relied upon the following references as
evidence of obviousness:
Tabuchi 4,440,841 Apr. 3, 1984
Bohlen et al. (Bohlen) 4,448,865 May 15, 1984
Leedy 5,580,687 Dec. 3, 1996
(filed June 7, 1995)
Claims 1 through 5 stand rejected under 35 U.S.C. § 112,
first paragraph, as failing to meet the written description
requirement (Answer, page 4). Claims 1-9 and 19 stand rejected
under 35 U.S.C. § 103(a) as unpatentable over Bohlen or Tabuchi
in view of Leedy (Answer, pages 5-13). We reverse all of the1
examiner’s rejections for reasons stated below.
OPINION
Appeal No. 1998-2329
Application No. 08/740,402
3
A. The Rejection under 35 U.S.C. § 112, ¶1
The examiner finds that the claims contain subject matter
which was not described in the specification in such a way as to
reasonably convey to one skilled in the art that the inventors
had possession of the subject matter in question, namely the
average stress and range of stresses as recited in claim 1 on
appeal (Answer, page 4). The examiner recognizes that the
specific stress values claimed are exemplified for a specific
case found on page 10 of the specification but states that there
is nothing in the specification to suggest that this specific
value would apply to all cases (id.).
Appellants argue that the example on page 10, lines 12-28,
of the specification essentially defines the “reduced stress”
limitation of the original claims and thus claim 1 on appeal has
been limited to a hard mask layer similar to that described on
page 10 of the specification (Brief, pages 7-8).
The initial burden of proof is on the examiner to establish
that the specification fails to reasonably convey to one of
ordinary skill in the art that appellants had possession of the
subject matter in question. See Vas-Cath Inc. v. Mahurkar, 935
Appeal No. 1998-2329
Application No. 08/740,402
4
F.2d 1555, 1563, 19 USPQ2d 1111, 1117 (Fed. Cir. 1991). The
examiner agrees with appellants that the specific stress values
recited in claim 1 on appeal are described on page 10, lines 25-
28, of the specification (Answer, page 4; Brief, page 8).
Accordingly, by inserting these stress values into claim 1 on
appeal, appellants have merely limited the claimed method to
hard mask material systems made under any conditions that
produce these stress values. The examiner has not met the
initial burden of proof by presenting any convincing evidence or
reasoning as to why the specification does not reasonably convey
to one of ordinary skill in the art that appellants were in
possession of these stress values for hard mask layers.
Accordingly, we cannot sustain the examiner’s rejection of
claims 1-5 under 35 U.S.C. § 112, first paragraph.
B. The Rejections under 35 U.S.C. § 103
The examiner finds that Bohlen does not teach the use of an
oxynitride material that reduces compressive and tensile stress
in the mask layer but merely discloses that the hard mask should
be made from an oxide (Answer, page 6; specifically, Bohlen
teaches silicon dioxide as a hard mask material, as found by the
examiner on page 5 of the Answer). Similarly, the examiner
Appeal No. 1998-2329
Application No. 08/740,402
The examiner finds that Tabuchi discloses a masking film2
comprising at least one layer from various selected metals,
metal oxides, and metal nitrides (see col. 2, ll. 29-33; col.
3, ll. 38-42). However, the examiner presents no convincing
evidence or reasoning that two or more of these materials in a
film would form an oxynitride mask film with stress values
within the ranges recited in claim 1 on appeal.
5
finds that Tabuchi does not disclose the stress effects of the
oxide and nitride or depositing the oxynitride by PECVD
processing (Answer, page 10).2
To remedy this deficiency of either Bohlen or Tabuchi, the
examiner applies Leedy for the teaching that a hard mask made of
silicon dioxide and silicon nitride forms an oxynitride which
together lower tensile stress levels (Answer, pages 5-6). The
examiner states that “[t]he purpose of the Leedy reference is to
demonstrate the combination of silicon nitride and silicon
dioxide to make an oxynitride and that oxynitrides provide
reduced stress.” Answer, page 14. However, the examiner has
not provided any factual basis in Leedy to support the above
noted findings. Leedy discloses that silicon oxide and silicon
nitride dielectric films are used as free standing membranes
(col. 6, ll. 27-34) and that deposition of these low stress
dielectric films on either side of the semiconductor layer will
Appeal No. 1998-2329
Application No. 08/740,402
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offset most compressive effects of oxide formation (col. 8, ll.
44-47). The two recipes taught by Leedy are for dielectric
membranes of silicon dioxide or silicon nitride (col. 11, ll.
14-16, emphasis added). Leedy further teaches that these free
standing membranes may be used as lithographic masks, preferably
made from oxide and nitride low stress dielectrics (col. 38, ll.
4-14). The examiner has not presented any factual basis for the
findings that Leedy demonstrates the combination of silicon
nitride and silicon oxide as hard mask materials, nor that even
such combination would produce an oxynitride with stresses
within the ranges recited in claim 1 on appeal (see the Brief,
page 10).
Additionally, we note that both Bohlen and Leedy teach
reduction of mechanical tensions in the mask system by
depositing layers on both sides of the silicon frame substrate
to produce compensatory tensions (see Bohlen, col. 4, ll. 4-15;
col. 6, ll. 24-31; col. 10, ll. 61-66; and col. 12, ll. 42-44;
see Leedy, col. 8, ll. 44-47). Accordingly, the examiner has
failed to present any reason, suggestion or motivation for
combining these references as proposed, i.e., why would one of
ordinary skill in the art substitute the hard mask material of
Appeal No. 1998-2329
Application No. 08/740,402
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Leedy for the mask material of Bohlen if the stresses were
already offset by the deposited layers. See In re Dembiczak,
175 F.3d 994, 999, 50 USPQ2d 1614, 1617 (Fed. Cir. 1999).
For the foregoing reasons, we determine that the examiner
has not presented a sufficient factual basis to support a prima
facie case of obviousness. Accordingly, the examiner’s
rejections under 35 U.S.C. § 103 are reversed.
C. Summary
The rejection of claims 1-5 under 35 U.S.C. § 112, first
paragraph, is reversed. The rejection of claims 1-9 and 19
under 35 U.S.C. § 103 over Bohlen in view of Leedy is reversed.
The rejection of claims 1-9 and 19 under 35 U.S.C. § 103 over
Tabuchi in view of Leedy is reversed.
The decision of the examiner is reversed.
Appeal No. 1998-2329
Application No. 08/740,402
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REVERSED
CHUNG K. PAK )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
TERRY J. OWENS ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
THOMAS A. WALTZ )
Administrative Patent Judge )
TAW/jrg
Appeal No. 1998-2329
Application No. 08/740,402
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HARRY A. WOLIN
MOTOROLA, INC.
AUSTIN INTELLECTUAL PROPERTY LAW SECTION
MD: TX32/PL02 7700 WEST PALMER
AUSTIN, TX 78729
Appeal No. 1998-2329
Application No. 08/740,402
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1. A method of forming a hard mask for use in the
formation of a refractory radiation mask comprising the steps
of:
providing a membrane structure including a step of forming
a radiation absorbing layer to be patterned as a portion of the
membrane structure;
forming a hard mask layer on a surface of the radiation
absorbing layer of the membrane structure, the hard mask layer
including a material system creating an average stress in the
membrane structure of less than 1E08 dynes/cm and a range of2
stresses from + 1.5E08 dynes/cm to-1.5E08 dynes/cm and2 2
therefore reduced distortion of the membrane structure; and
patterning the hard mask layer.