Ex Parte WILK et al

Board of Patent Appeals and Interferences

Mar 23, 2004

09396642 (B.P.A.I. Mar. 23, 2004)

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not written for publication and is not binding precedent of the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. 18
UNITED STATES PATENT AND TRADEMARK OFFICE
__________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________
Ex parte GLEN D. WILK,
ROBERT M. WALLACE,
JOHN M. ANTHONY
and PAUL MCINTYRE
__________
Appeal No. 2004-0652
Application 09/396,642
___________
ON BRIEF
___________
Before FRANKFORT, STAAB, and MCQUADE, Administrative Patent
Judges.
MCQUADE, Administrative Patent Judge.
DECISION ON APPEAL
Glen D. Wilk et al. originally took this appeal from the
final rejection (Paper No. 7) of claims 1 through 12. Upon
consideration of the appellants’ main brief (Paper No. 9), the
examiner issued an Office action (Paper No. 10) reopening
prosecution and entering superseding rejections of the claims.
Pursuant to 37 CFR § 1.193(b)(2)(ii), the appellants filed a
supplemental brief (Paper No. 11) and requested that the appeal
be reinstated. Implicitly denying this request, the examiner
issued another Office action (Paper No. 12) entering further
Appeal No. 2004-0652
Application No. 09/396,642
2
superseding rejections of the claims. In response, the
appellants filed a second supplemental brief (Paper No. 13) and
again requested that the appeal be reinstated. The examiner then
entered an answer (Paper No. 14), noted a reply brief (Paper No.
15) filed by the appellants and forwarded the application to this
Board for review of the current rejections of claims 1 through
12. Claims 13 through 15, the only other claims pending in the
application, stand withdrawn from consideration.
THE INVENTION
The invention relates to “semiconductor device fabrication
and processing” (specification, page 1). Representative claims 1
and 9 read as follows:
1. A method of forming an electrically conductive structure
insulatively spaced from a second structure, said method
comprising the steps of:
providing said second structure;
forming an electrically insulative layer on said second
structure;
forming on said electrically insulative layer and spaced
form [sic, from] said second structure an unoxidized electrically
conductive structure of a material that remains substantially
conductive in the oxidized state; and
then subjecting said electrically conductive structure and
said electrically insulative layer to an ozone containing
atmosphere for a duration of time and at a first temperature
sufficient to oxidize said unoxidized electrically conductive
structure.
9. A method of forming a capacitor over a semiconductor
substrate, said method comprising the steps of:
providing a first electrically conductive electrode on said
semiconductor substrate;
Appeal No. 2004-0652
Application No. 09/396,642
3
forming a dielectric layer on said first electrically
conductive electrode comprised of a first conductive material;
forming on said dielectric layer a second unoxidized
electrically conductive electrode comprised of a second
electrically conductive material which remains electrically
conductive in the oxidized state; and
then oxidizing said second electrically conductive material
by subjecting said second electrically conductive material and
said dielectric layer to an ozone-containing atmosphere for a
period of time greater than 20 minutes but less than 70 minutes.
THE PRIOR ART
The references relied on by the examiner to support the
rejections on appeal are:
Wong 5,423,944 Jun. 13, 1995
Nishioka et al. (Nishioka) 5,554,564 Sep. 10, 1996
THE REJECTIONS
Claims 1, 2, 4, 5 and 7 stand rejected under 35 U.S.C.
§ 102(b) as being anticipated by Nishioka.
Claims 3 and 6 through 12 stand rejected under 35 U.S.C.
§ 103(a) as being unpatentable over Nishioka in view of Wong.
Attention is directed to the appellants’ briefs (Paper Nos.
9, 11, 13 and 15) and to the examiner’s answer (Paper No. 14) for
the respective positions of the appellants and the examiner
regarding the merits of these rejections.
Appeal No. 2004-0652
Application No. 09/396,642
4
DISCUSSION
I. The 35 U.S.C. § 102(b) rejection of claims 1, 2, 4, 5 and 7 as
being anticipated by Nishioka
Nishioka pertains to methods for forming capacitors
containing materials having high dielectric constants. In
general, the capacitors comprise a silicon semiconductor
substrate 30, an insulative SiO2 layer 32 overlying the
substrate, a TiSi2/poly-Si plug 34 providing electrical
connection through the SiO2 layer, a lower electrode consisting
of a conductive adhesion layer 36 or 46 of either TiN (Figures 1
through 4) or Ru (Figures 5 through 8) deposited on the SiO2
layer and a Pt layer 38 overlying the adhesion layer, a high
dielectric constant BST layer 42 deposited over the lower
electrode, and an upper electrode consisting of a Pt layer 44
overlying the BST layer. In order to minimize expansion and
cracking of the BST layer 42 during its formation, Nishioka
deposits the respective adhesion layers in a substantially
unoxidized state and then pre-oxidizes their sidewalls to reduce
any further oxidation and expansion during the BST layer
deposition (see column 4, lines 39 through 63). The pre-
oxidation step forms a non-conductive TiO2 sidewall 40 on the TiN
adhesion layer 36 and a conductive RuO2 sidewall 50 on the Ru
adhesion layer 46. With regard the pre-oxidation of the TiN
Appeal No. 2004-0652
Application No. 09/396,642
5
adhesion layer 36, Nishioka teaches that “[t]he structure is then
annealed in a diluted oxygen (5%O2 in N2) gas at 650°C. to form
TiO2 sidewall 40 as shown in FIG. 2 . . . [or] [a]lternatively,
ozone could be used for annealing . . . [or] [a]lternatively, the
structure could be annealed at a lower temperature (e.g. 600°C.)”
(column 5, lines 56 through 62). As for the pre-oxidation of the
Ru adhesion layer 46, Nishioka teaches that “[t]he structure is
then annealed in an oxygen containing atmosphere to form RuO2
sidewall 50 as shown in FIG. 6” (column 6, lines 26 and 27).
Anticipation is established only when a single prior art
reference discloses, expressly or under principles of inherency,
each and every element of a claimed invention. RCA Corp. v.
Applied Digital Data Sys., Inc., 730 F.2d 1440, 1444, 221 USPQ
385, 388 (Fed. Cir. 1984). In other words, there must be no
difference between the claimed invention and the reference
disclosure, as viewed by a person of ordinary skill in the field
of the invention. Scripps Clinic & Research Found. v. Genentech
Inc., 927 F.2d 1565, 1576, 18 USPQ2d 1001, 1010 (Fed. Cir. 1991).
It is not necessary that the reference teach what the subject
application teaches, but only that the claim read on something
disclosed in the reference, i.e., that all of the limitations in
the claim be found in or fully met by the reference. Kalman v.
Appeal No. 2004-0652
Application No. 09/396,642
6
Kimberly Clark Corp., 713 F.2d 760, 772, 218 USPQ 781, 789 (Fed.
Cir. 1983), cert. denied, 465 U.S. 1026 (1984).
In rejecting claims 1, 2, 4, 5 and 7, the examiner focuses
on Nishioka’s disclosure of the Ru adhesion layer embodiment
illustrated in Figures 5 through 8. The determination by the
examiner that this disclosure is anticipatory is well founded
with respect to the subject matter recited in claims 1, 2, 5 and
7, but not with respect to the subject matter recited in claim 4.
Using the language in claim 1 as a guide, and
notwithstanding the appellants’ arguments to the contrary,
Nishioka discloses a method of forming an electrically conductive
structure insulatively spaced from a second structure (see
Nishioka’s Figures 5 through 8), which method comprises the steps
of: providing said second structure (Nishioka’s silicon
semiconductor substrate 30); forming an electrically insulative
layer (Nishioka’s insulative SiO2 layer 32) on said second
structure; forming on said electrically insulative layer and
spaced from said second structure an unoxidized electrically
conductive structure (Nishioka’ conductive Ru adhesion layer 46)
of a material that remains substantially conductive in the
oxidized state (conductive RuO2); and then subjecting said
electrically conductive structure and said electrically
Appeal No. 2004-0652
Application No. 09/396,642
7
insulative layer to an ozone-containing atmosphere for a duration
of time and at a first temperature sufficient to oxidize said
unoxidized electrically conductive structure (see Nishioka at
column 5, lines 56 through 62; and column 6, lines 26 and 27).
With regard to this last step, although Nishioka explicitly
mentions ozone only in connection with the annealing and
oxidation of the conductive TiN adhesion layer 36, a fair reading
of the reference as a whole indicates that a person of ordinary
skill in the art would view Nishioka’s broad statement that the
conductive Ru adhesion layer 46 is annealed and oxidized in an
oxygen containing atmosphere as intending to encompass the same
conditions expressed in conjunction with the corresponding and
directly related TiN annealing and oxidation step. These
conditions include the use of ozone, which is of course an oxygen
containing atmosphere, and a 600°C. annealing temperature.
Furthermore, Nishioka’s conductive Ru adhesion layer 46
meets the recitation in dependent claim 2 that the electrically
conductive structure is comprised of a material selected from the
group consisting of: Ir, Ru, Rh and any combination thereof,
Nishioka’s insulative SiO2 layer 32 (an oxide) meets the
recitation in dependent claim 5 that the electrically insulative
layer is comprised of a material selected from the group
Appeal No. 2004-0652
Application No. 09/396,642
8
consisting of: tantalum pentoxide, BST, PZT, a silicate, an
oxide, a nitride, a combination thereof and a stack of one or
more thereof, and Nishioka’s teaching that the annealing and
oxidation step can take place at a temperature of 600°C. meets
the recitation in claim 7 that the first temperature is around 20
to 600 C.
On the other hand, Nishioka’s description of the use of
ozone in the annealing and oxidation step is not specific enough
to meet the recitation in dependent claim 4 of “remotely” forming
the ozone.
In light of the foregoing, we shall sustain the standing 35
U.S.C. § 102(b) rejection of claims 1, 2, 4, 5 and 7 as being
anticipated by Nishioka with respect to claims 1, 2, 5 and 7, but
not with respect to claim 4.
II. The 35 U.S.C. § 103(a) rejection of claims 3 and 6 through 12
as being unpatentable over Nishioka in view of Wong
Wong discloses a method for etching a silicon wafer using
hydrogen fluoride and water vapor combined with ozone. Of
interest is Wong’s teaching that the ozone may be produced (1) in
a remote plasma generator or (2) in the etching apparatus itself
using ultraviolet excitation (see column 2, lines 49 through 57).
Appeal No. 2004-0652
Application No. 09/396,642
1 In the event of further prosecution, the examiner should
consider whether Nishioka, taken in combination with Wong’s
teaching of forming ozone at a location remote from where it is
intended to be used, would have suggested the subject matter
recited in claim 4, thereby warranting a § 103(a) rejection.
9
In neither case, however, is the ozone formed over the subject
silicon wafer.1
As explained above, Nishioka meets the temperature
limitation in dependent claim 7. We shall therefore sustain the
standing 35 U.S.C. § 103(a) rejection of claim 7 as being
unpatentable over Nishioka in view of Wong, with the examiner’s
application of Wong here being harmless surplusage.
We shall not sustain, however, the standing 35 U.S.C.
§ 103(a) rejection of claims 3, 6 and 8 which depend from claim
1. The examiner has not cogently explained, and it is not
apparent, how or why the combined teachings of Nishioka and Wong
would have suggested performing Nishioka’s annealing and
oxidation step with an ozone-containing atmosphere formed over
the electrically conductive structure and the electrically
insulative layer as recited in claim 3, for more than 20 minutes
but less than 70 minutes as recited in claim 6, or at a
temperature around 400 to 500C as recited in claim 8.
We also shall not sustain the standing 35 U.S.C. § 103(a)
Appeal No. 2004-0652
Application No. 09/396,642
10
rejection of independent claim 9 and dependent claims 10 through
12 as being unpatentable over Nishioka in view of Wong.
As indicated above, claim 9 recites a method of forming a
capacitor over a semiconductor substrate comprising, inter alia,
the step of oxidizing the second electrically conductive material
by subjecting it and the dielectric layer to an ozone-containing
atmosphere for a period of time greater than 20 minutes but less
than 70 minutes. In apparent recognition that Nishioka’s
oxidizing step is performed on an electrically conductive
material that corresponds to the first, rather than the second,
electrically conductive material recited in claim 9, the examiner
appears to conclude (see page 4 in the answer) that it would have
been obvious to simply interchange Nishioka’s first electrically
conductive layer (conductive Ru layer 46 and Pt layer 38) and
second conductive layer (Pt layer 44). The combined teachings of
Nishioka and Wong provide no suggestion for this modification
which is completely inconsistent with the fair teachings of
Nishioka or for the 20 to 70 minute time limitation.
Appeal No. 2004-0652
Application No. 09/396,642
11
SUMMARY
The decision of the examiner to reject claims 1 through 12
is affirmed with respect to claims 1, 2, 5 and 7, and reversed
with respect to claims 3, 4, 6 and 8 through 12.
No time period for taking any subsequent action in
connection with this appeal may be extended under 37 CFR
§ 1.136(a).
AFFIRMED-IN-PART
CHARLES E. FRANKFORT )
Administrative Patent Judge )
)
) BOARD OF PATENT
)
) APPEALS AND
LAWRENCE J. STAAB )
Administrative Patent Judge ) INTERFERENCES
)
)
)
)
)
JOHN P. MCQUADE )
Administrative Patent Judge )
JPM/kis
Appeal No. 2004-0652
Application No. 09/396,642
12
TEXAS INSTRUMENTS INCORPORATED
P. O. BOX 655474, M/S 3999
DALLAS, TX 75265