Ex parte Kulwicki

Board of Patent Appeals and Interferences

Jan 10, 2001

08315454 (B.P.A.I. Jan. 10, 2001)

The real party in interest is Texas Instruments, Incorporated.1
Application for patent filed September 30, 1994.2
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is not binding precedent of the Board.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. 14
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte BERNARD M. KULWICKI1
____________
Appeal No. 1997-3335
Application No. 08/315,4542
____________
ON BRIEF
____________
Before McKELVEY, Senior Administrative Patent Judge and WALTZ
and TIMM, Administrative Patent Judges.
TIMM, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134 from an examiner's final rejection of claims
1-10, which are all of the claims pending in this application.
Appeal No. 1997-3335 Page 2
Application No. 08/315,454
BACKGROUND
Appellant's invention relates to a method of forming a dielectric film of barium and/or strontium
titanate on a microelectronic device and a method of forming a capacitive structure. Claims 1 and 8 are
illustrative:
1. A method of forming a barium and/or strontium titanate dielectric film on a microelectronic
device, said method comprising:
(a) preparing a precursor solution by combining a boron compound, a titanium compound, and
a precursor selected from the group consisting of barium compounds, strontium compounds, and
combinations thereof, such that the molar ratio of boron to titanium in said precursor solution is between
0.001 and 0.1;
(b) depositing and densifying one or more layers of said precursor solution to form a precursor
film on said device; and
(c) annealing said precursor film in an oxygen-containing atmosphere, thereby forming said
dielectric film comprising substantially uniformly distributed first and second phases, said first phase
containing a plurality of barium and/or strontium titanate grains and said second phase principally
comprising boron oxide, whereby said boron in said precursor apparently lowers the processing
temperature required to produce said titanate grains, and whereby boron additionally decreases the
dielectric leakage current observed for said dielectric film.
8. A method of forming a capacitive structure on a microelectronic device, said capacitive
structure having a dielectric laminate disposed between a first electrode and a second electrode, said
method comprising:
(a) forming said first electrode on a substrate;
(b) depositing two or more precursor films over said first electrode, each of said films
comprising titanium and at least one of barium and strontium, at least one of said films further
comprising boron in a ratio to said titanium of at least 0.001;
Appeal No. 1997-3335 Page 3
Application No. 08/315,454
(c) annealing said films at a temperature above 450 C in an oxygen-containing atmosphere,
thereby forming said dielectric laminate comprising a plurality of grains with a perovskite crystal
structure, each grain comprising titanium, oxygen, and at least one of barium and strontium, said
dielectric laminate further comprising boundary regions between said grains, essentially all of said boron
existing in said boundary regions as B O ; and2 3
(d) forming a second electrode over said dielectric laminate.
The prior art references of record relied upon by the Examiner in rejecting the appealed claims
are:
Soong 4,379,854 Apr. 12, 1983
Bhargava et al. (Bhargava) 4,959,089 Sep. 25, 1990
Lipeles et al. (Lipeles) 4,963,390 Oct. 16, 1990
Takagi et al. (Takagi) 4,988,650 Jan. 29, 1991
Abe et al. (Abe) 5,292,694 Mar. 8, 1994
Kulwicki et al. (Kulwicki) 5,368,834 Nov. 29, 1994
(filed Aug. 13, 1993)
Kim et al. (Kim) 5,378,667 Jan. 3, 1995
(filed Dec. 10, 1993)
Claims 1-5 and 7 stand rejected under 35 U.S.C. § 103 as being unpatentable over Lipeles in
combination with any one of Abe, Takagi, Bhargava or Soong. Claim 6 stands rejected under 35
U.S.C. § 103 as being unpatentable over the above mentioned prior art references and further in view
of Kulwicki. Claims 8-10 stand rejected under 35 U.S.C. § 103 as being unpatentable over all of the
above prior art references and still further in view of Kim. We reverse for the reasons that follow.
Appeal No. 1997-3335 Page 4
Application No. 08/315,454
OPINION
We have reviewed the respective positions presented by Appellants and the Examiner. In so
doing, we find ourselves in agreement with Appellants that the applied prior art fails to establish a
prima facie case of obviousness of the claimed subject matter. Accordingly, we reverse the
Examiner's rejection for essentially those reasons advanced by Appellants, and we add the following
primarily for emphasis.
“A critical step in analyzing the patentability of claims pursuant to section 103(a) is casting the
mind back to the time of invention, to consider the thinking of one of ordinary skill in the art, guided
only by the prior art references and the then-accepted wisdom in the field.” In re Kotzab, 217 F.3d
1365, 1369-70, 55 USPQ2d 1313, 1316-17 (Fed. Cir. 2000). “The invention must be viewed not
with the blueprint drawn by the inventor, but in the state of the art that existed at the time.” In re
Dembiczak, 175 F.3d 994, 999, 50 USPQ2d 1614, 1617 (Fed. Cir. 1999)(quoting Interconnect
Planning Corp. v. Feil, 774 F.2d 1132, 1138, 227 USPQ 543, 547 (Fed. Cir. 1985). To establish a
prima facie case of obviousness, “there must be some teaching, suggestion or motivation in the prior
art to make the specific combination that was made by the applicant.” In re Dance, 160 F.3d 1339,
1343, 48 USPQ2d 1635, 1637 (Fed. Cir. 1998). “In other words, the examiner must show reasons
that the skilled artisan, confronted with the same problems as the inventor and with no knowledge of the
Appeal No. 1997-3335 Page 5
Application No. 08/315,454
claimed invention, would select the elements from the cited prior art references for combination in the
manner claimed.” In re Rouffet, 149 F.3d 1350, 1357, 47 USPQ2d 1453, 1458 (Fed.Cir. 1998).
Claim 1 recites a method of forming a barium and/or strontium titanate dielectric film on a
microelectronic device. In essence, the process involves forming a precursor solution, depositing one
or more layers of the solution on a microelectronic device, densifying the layers to form a precursor film
and annealing the film in an oxygen-containing atmosphere. The precursor solution is formed by
combining three ingredients; a boron compound, a titanium compound, and a precursor. The precursor
can be a barium compound. The boron is required to be present in the precursor solution in a molar
ratio of boron to titanium of 0.001 to 0.1.
The Examiner has applied a prior art reference, Lipeles, which teaches a metallo-organic
solution deposition (MOSD) process for forming thick, transparent, crystalline films from ferroelectric
oxides such as barium titanate, BaTiO (col. 1, lines 14-21). The MOSD process includes steps of (a)3
combining metallo-organic starting materials to form a coating solution; (b) depositing the solution on a
substrate by spin casting or dip coating, removing solvent by low temperature drying and
drying/densifying by rapid heating at about 400°C to leave an amorphous film; and (c) after several
layers are built up, annealing at about 535 to 800°C to form a crystallized oxide film (col. 2, lines 30-
62). In order to make barium titanate, one of ordinary skill in the art would presumably combine a
Appeal No. 1997-3335 Page 6
Application No. 08/315,454
barium compound starting material and a titanium compound starting material. Lipeles does not
describe including a boron compound in the solution.
The Examiner turns to Abe, Takagi, Bhargava and Soong for the missing description of using
boron compounds in dielectric films. The Examiner suggests that these references all teach that B O or2 3
H BO reduces the sintering temperature of the dielectric ceramic film BaTiO . The Examiner3 3 3
concludes that it would have been obvious for one of ordinary skill in the art at the time the invention
was made to have modified the Lipeles metallo-organic film process with a boron additive as suggested
by the secondary references to lower annealing temperatures, enable the use of lower cost electrode
compositions and thus lower the cost of manufacturing (Answer, pages 5 and 6).
However, we are not convinced that Abe, Takagi, Bhargava or Soong would have led one of
ordinary skill in the art to add a boron compound to the coating solution of Lipeles. Abe, Takagi, and
Soong describe powder processing techniques for forming sintered ceramics. Bhargava is directed to
a process of melting powders at 1300-1400°C to form a glass, placing the glass on a substrate and
remelting and heating at 950 to 1050°C (col. 1, line 47 to col. 2, line 5). Appellants point out that the
temperatures, homogeneity, and the reactions differ significantly between the solution process of Lipeles
and the higher temperature powder and melt processes of the secondary references (Brief, page 16).
The Examiner has provided no convincing rationale tending to show that one of ordinary skill in the art
would have had a reasonable expectation that the boron compounds of the secondary references would
Appeal No. 1997-3335 Page 7
Application No. 08/315,454
Abe teaches firing at temperatures of 962°C or lower, preferably 900°C or lower (col. 5, lines3
17-22) or around 900°C (col. 13, lines 39-42). Takagi describes firing at temperatures of 800 to
1350°C (col. 5, lines 24-27). Soong describes firing at temperatures of 2050°F, i.e. 1121°C (col. 2,
lines 24-27).
behave the same way in the solution process as they do in the powder and melt processes. From the
evidence on the record, there is no basis to believe that one of ordinary skill in the art would have
reasonably expected the boron compounds of the secondary references to reduce the 525-800°C
annealing temperature of Lipeles in the same way the boron compounds reduce the firing temperatures
of the powder processes. We note that the firing temperatures of Abe, Takagi and Soong are all above
800°C . Absent from the applied prior art is the requisite suggestion or motivation for combining the3
applied reference teachings, based upon a reasonable expectation of success, in such a manner as to
result in the Appellants’ claimed subject matter. In re O’Farrell, 853 F.2d 894, 903-904, 7 USPQ2d
1673, 1680-1681 (Fed. Cir. 1988).
With respect to claim 1, we also note that Bhargava specifies using 18-32 mole % boron oxide
and 18-32 mole % titanium oxide. Thus, the molar ratio of boron to titanium is 18:32 to 32:18 which
converts to 0.56 to 1.8. Claim 1 requires a boron to titanium ratio of between 0.001 and 0.01. Even if
there was a reason, suggestion or motivation to use the boron compound of Bhargava in the solution of
Lipeles, one of ordinary skill in the art would have been led to use a much higher amount of boron than
called for by claim 1.
Appeal No. 1997-3335 Page 8
Application No. 08/315,454
Claim 1 also requires that the dielectric film formed comprise substantially uniformly distributed
first and second phases. The first phase must contain a plurality of barium and/or strontium titanate
grains and the second phase must principally comprise boron oxide. The Examiner reasons that the
combination of references teaches identical precursors and similar temperature ranges and thus the
perovskite film as recited and claimed would be inherently obtained (Answer, page 8). However,
assuming one of ordinary skill in the art would combine the teachings of the references and use the
boron compounds of the secondary references in the process of Lipeles, one of ordinary skill in the art
would be required to perform experimentation to optimize the level of boron for reducing the annealing
temperature. While it is possible that the result would be a first phase of barium titanate grains and a
second phase of boron oxide, the phases being substantially uniformly distributed, it is not a certainty.
“Inherency ... may not be established by probabilities or possibilities. The mere fact that a certain thing
may result from a given set of circumstances is not sufficient.” Mehl/Biophile Int’l Corp. v.
Milgraum, 192 F.3d 1362, 1365, 52 USPQ2d 1303, 1305 (Fed. Cir. 1999). See also Glaxo, Inc.
v. Novopharm Ltd., 830 F.Supp. 871, 874, 29 USPQ2d 1126, 1128 (E.D. N.C. 1993), aff’d, 34
USPQ2d 1565 (Fed. Cir.), cert. denied, 516 U.S. 988 (1995)(“[I]t is not sufficient that a person
following the disclosure sometimes obtain the result set forth in the claim, it must invariably happen.”).
With respect to the other independent claim, claim 8, the Examiner adds Kulwicki and Kim to
the rejection but does not indicate where, in any of the prior art references relied upon, a process is
Appeal No. 1997-3335 Page 9
Application No. 08/315,454
taught including steps of forming an electrode on a substrate, depositing two or more precursor films
over the electrode, annealing and forming a second electrode over the annealed laminate. Kim
describes forming the dielectric ceramic and then forming the electrodes on both surfaces of the
dielectric. The sequence of layer forming is different than that required by the process of claim 8.
We conclude that, on the present record, the Examiner has not established a prima facie case
of obviousness with respect to claims 1-10. Therefore, we reverse.
OTHER ISSUES
We are unsure how “apparently” limits claim 1. Page 3 of the specification seems to indicate
that the temperature requirements may or may not be reduced. We have not found it necessary to rely
on the language of claim 1 reciting “whereby said boron in said precursor apparently lowers the
processing temperature required to produce said titanate grains” as this language does not seem to
further limit the method. “While it is not a requirement of patentability that an inventor correctly set
forth, or even know, how or why the invention works, neither is the patent applicant relieved of the
requirement of teaching how to achieve the claimed result, even if the theory of operation is not
correctly explained or even understood.” Newman v. Quigg, 877 F.2d 1575, 1581, 11 USPQ2d
1340, 1345 (Fed. Cir. 1989), cert. denied, 495 U.S. 932 (1990)(citations omitted). That being said,
Appellant may wish to delete the theory from claim 1.
Appeal No. 1997-3335 Page 10
Application No. 08/315,454
REVERSED
FRED E. McKELVEY )
Senior Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
THOMAS A. WALTZ ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
CATHERINE TIMM )
Administrative Patent Judge )
Appeal No. 1997-3335 Page 11
Application No. 08/315,454
RICHARD A STOLTZ
TEXAS INSTRUMENTS INCORPORATED
PO BOX 655474 MS 219
DALLAS TX 75265
APPEAL NO. 1997-3335 - JUDGE TIMM
APPLICATION NO. 08/315,454
APJ TIMM
APJ McKELVEY
APJ WALTZ
DECISION: REVERSED
Prepared By: Leticia Pihulic
DRAFT TYPED: 05 Feb 02
FINAL TYPED: