Ex Parte Srinivasan et al

Board of Patent Appeals and Interferences

Jun 1, 2009

10769430 (B.P.A.I. Jun. 1, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte ANAND SRINIVASAN, GURTEJ SANDHU,
and RAVI IYER
____________

Appeal 2008-005349
Application 10/769,430
Technology Center 2800
____________

Decided1: June 2, 2009
____________

Before ADRIENE LEPIANE HANLON, PETER F. KRATZ, and
ROMULO H. DELMENDO, Administrative Patent Judges.

DELMENDO, Administrative Patent Judge.

DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134(a) from a final rejection of
claims 43-76 (Appeal Brief filed January 5, 2007, hereinafter “Br.,” 1, 3;
Final Office Action mailed February 10, 2006). We have jurisdiction under
35 U.S.C. § 6(b).
We REVERSE.

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, begins to run from the decided date
shown on this page of the decision. The time period does not run from the
Mail Date (paper delivery) or Notification Date (electronic delivery).
Appeal 2008-005349
Application 10/769,430

STATEMENT OF THE CASE
Appellants’ invention relates to a method of forming an insulating
material in which an insulating material comprising fluorine, silicon, and
oxygen is deposited on a substrate provided within a reaction chamber
together with reactants comprising Si, F, and O3 (Specification, hereinafter
“Spec.,” 3, ll. 7-11).
Claims 43, 63, 67, and 74, which are the only independent claims on
appeal, read as follows:
43. A method of forming a fluorine doped insulating
material comprising:
providing a substrate within a reaction chamber, the
reaction chamber controlled within a range of temperatures
from about 400°C to about 700°C;
providing reactants comprising silicon, fluorine and
ozone within the reaction chamber and maintaining a pressure
within the reaction chamber of from about 400 Torr to about 1
atmosphere; and
depositing an insulating material, at a rate of from about
8000 angstroms per minute (Å/min) to about 10000 Å/min,
comprising fluorine, silicon and oxygen onto the substrate from
the reactants, wherein the depositing occurs with a plasma
being present in the reaction chamber.
63. A method of forming a silicon oxide having Si-F
bonds, comprising:
providing a reaction chamber at a temperature of from
about 400ºC to about 700°C;
positioning a substrate within the reaction chamber;
providing an ozone comprising reactant and a precursor
having Si-F bonds to the substrate within the reaction chamber
and maintaining a pressure within the reaction chamber of from
about 400 Torr to about 1 atmosphere;
while providing the ozone comprising reactant and the
precursor having Si-F bonds to the substrate, providing a
plasma within the reaction chamber; and
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causing a silicon oxide having Si-F bonds, to deposit
onto the substrate within the reaction chamber at a rate of from
about 8000 angstroms per minute (Å/min) to about 10000
Å/min.
67. A method of forming a silicon oxide having Si-F
bonds, comprising:
providing a substrate within a CVD reaction chamber at a
pressure of from about 1 Torr to about 760 Torr and at a
substrate temperature of from about 400ºC to about 700°C;
flowing F-TES into the reaction chamber at a flow rate of
from about 100 mg/min to about 1,000 mg/min;
flowing an ozone-containing gas into the reaction
chamber at a flow rate of from about 1,000 sccm to about 8,000
sccm, the gas containing a mixture of from about 5 vol% to
about 15 vol% ozone in O2;
providing the F-TES and ozone-containing gas
simultaneously in the reaction chamber; and
depositing a silicon oxide having Si-F bonds onto the
substrate at a rate of from about 500 Å/min to about 10,000
Å/min with a plasma present in the reaction chamber, the
silicon oxide comprising from about 2 atomic % to about 10
atomic % fluorine, comprising more fluorine than occurs in a
silicon oxide deposited from an otherwise identical method
using O2 or H2O2 instead of O3, exhibiting a flow temperature
that is from about 50°C to about 100°C less than occurs in an
otherwise identical silicon oxide lacking the fluorine, exhibiting
a dielectric constant that is less than occurs in an otherwise
identical silicon oxide lacking the fluorine, and exhibiting a
fixed charge that is less than occurs in a silicon oxide deposited
from an otherwise identical method using TEOS instead of F-
TES.
74. A method of forming silicon oxide having Si-F
bonds, comprising:
providing a substrate within a single wafer, cold wall,
CVD reaction chamber at a pressure of 600 Torr and at a
substrate temperature of 500ºC;
flowing F-TES into the reaction chamber at a flow rate of
from about 100 mg/min to about 1,000 mg/min;
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flowing an ozone-containing gas into the reaction
chamber at a flow rate of 2,000 sccm, the gas containing a
mixture of from about 5 vol% to about 15 vol% ozone in O2;
providing the F-TES and ozone-containing gas
simultaneously in the reaction chamber; and
depositing a silicon oxide having Si-F bonds onto the
substrate at a rate of 8,000 Å/min with a plasma present in the
reaction chamber, the silicon oxide comprising 2 atomic %
fluorine.
(Claims App’x; Br. 20, 23, 25, 27.)

The Examiner relied upon the following as evidence of
unpatentability (Examiner’s Answer mailed June 1, 2007, hereinafter
“Ans.,” 2):
Vassiliev 5,876,798 Mar. 2, 1999
Ryu 5,908,672 Jun. 1, 1999
Kirchhoff 6,057,250 May 2, 2000

The Examiner rejected the claims under 35 U.S.C. § 103(a) as
follows:
I. claims 43-49, 54, 55, 62-66, 74, and 75 as unpatentable over
Ryu in view of Vassiliev (Ans. 3-11);
II. claims 67-69, 71, and 72 as unpatentable over Ryu (id. at 11-
15);
III. claim 70 as unpatentable over Ryu in view of Vassiliev (id. at
15-16);
IV. claims 50-53 and 56-61 as unpatentable over Ryu, Vassiliev,
and Kirchhoff (id. at 16); and
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V. claims 73 and 76 as unpatentable over Ryu in view of Kirchhoff
(id. at 16-17).2

ISSUES
I. Claims 43-49, 54, 55, 62-66, 74 & 75 over Ryu & Vassiliev
With respect to each of the independent claims (claims 43, 63, and 74)
subject to this rejection, the Examiner acknowledges that one of the
differences between the claimed subject matter and Ryu is that Ryu discloses
a deposition rate of 3,000 to 4,500 Å/min, which is lower than the rates
recited in these claims (i.e., “about 8000 . . . to about 10000 Å/min” in
claims 43 and 63 and “8,000 Å/min” in claim 74) (Ans. 4-10). Nevertheless,
the Examiner asserts that Appellants’ Specification “contains no disclosure
of either the critical nature of the claimed deposition rate . . . of [sic, or] any
unexpected results arising therefrom” (id. at 4, 7, and 10). According to the
Examiner, “it would have been obvious to one having ordinary skill in the
art . . . to deposit the insulating material of Ryu at a higher rate as taught by
Vassiliev because plasma enhanced deposition does have some short term
advantages such as higher deposition rate” (id. at 4-5). With respect to claim
74, the Examiner further asserts that “the claimed mixture of from about 5%
to about 15[%] ozone in O2, do[es] not appear to be critical” (id. at 10).
Appellants, on the other hand, contend that “neither Ryu nor Vassiliev
disclose[s] or suggest[s] the claimed deposition rate of about 8000 to about
10000 angstroms per minute” (Br. 10). According to Appellants, Ryu
“expressly requires a low deposition rate of less than 4500 angstroms per

2 The Examiner indicated that the rejections under 35 U.S.C. § 112, ¶1,
(Final Office Action at 2-4) have been withdrawn (Ans. 17).
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minute to preclude the voids that result from prior art depositions” and thus
“expressly teaches against depositing with a plasma at the much higher
deposition rate” recited in the claims (id.). With respect to claim 74,
Appellants further contend that Ryu merely teaches that ozone may be used
in place of oxygen (id. at 14). Specifically, Appellants argue that “Ryu fails
to appreciate any significance in the presence of ozone in comparison to O2”
(id.).
Thus, the issues arising from the respective positions of the Examiner
and Appellants are:
(1) Have Appellants shown reversible error on the part of the
Examiner in concluding that a person having ordinary skill in the art would
have had a reason to increase Ryu’s disclosed deposition rate of less than
about 4500 Å/min to “about 8000” or “8000” Å/min as recited in
independent claims 43, 63, and 74?
(2) Have Appellants shown reversible error on the part of the
Examiner in concluding that a person having ordinary skill in the art would
have had a reason to use a mixture of about 5 to about 15 vol% of ozone in
O2 as recited in claim 74?

II. Claims 67-69, 71, & 72 over Ryu
In addressing the limitation “flowing an ozone-containing gas into the
reaction chamber . . . the gas containing a mixture of from about 5 vol% to
about 15 vol% ozone in O2” in claim 67 (the only independent claim subject
to this rejection), the Examiner asserts that the limitation “do[es] not appear
to be critical” (Ans. 13). The Examiner then concludes that “it would have
been obvious to one having ordinary skill in the art . . . to determine the
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appropriate percentage of ozone in oxygen mixture since the rate of reaction
between F-TES and oxygen are well known to the workers in the art” (id).
Appellants, on the other hand, urge that Ryu merely teaches that
ozone may be used in place of oxygen (Br. 16). According to Appellants,
“Ryu fails to appreciate any significance in the presence of ozone in
comparison to O2” (id.).
Thus, an issue arising from the contentions of the Examiner and
Appellants is:
(3) Have Appellants shown reversible error on the part of the
Examiner in concluding that a person having ordinary skill in the art would
have had a reason to use a mixture of about 5 to about 15 vol% of ozone in
O2 as recited in claim 67?

III. Claim 70 over Ryu & Vassiliev
Appellants rely on the same arguments made in support of Rejection
II (Br. 18). Accordingly, the issue raised in this rejection is the same as in
Rejection II.

IV. Claims 50-53 & 56-61 over Ryu, Vassiliev, & Kirchhoff
With respect to claims 50-53 and 56-61 (which all directly or
indirectly depend from claim 43), the Examiner relies on Kirchhoff for its
teaching that “dopants such as boron and phosphorus can be added into a
fluorine doped oxide material to lower the flow temperature” (Ans. 16).
Appellants, on the other hand, contend that “Kirchhoff does not
remedy and is not alleged to remedy the deficiencies of Ryu in view of
Vassiliev . . . with regard to claim 43” (Br. 19).
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Accordingly, the issue raised in this rejection is the same as in
Rejection I.

V. Claims 73 & 76 over Ryu & Kirchhoff
With respect to claims 73 and 76 (which depend from claims 67 and
74 respectively), the Examiner again relies on Kirchhoff for its teaching that
“dopants such as boron and phosphorus can be added into a fluorine doped
oxide material to lower the flow temperature” (Ans. 16).
Appellants, on the other hand, contend that that “Kirchhoff does not
remedy and is not alleged to remedy the deficiencies of Ryu as applied to
claims 67 and 74” (Br. 19).
Thus, the issues raised in Rejection V are identical to Issues (2) and
(3) above.

FINDINGS OF FACT
1. Ryu teaches that plasma enhanced chemical vapor deposition
(PECVD) has been used to form doped passivation (insulating)
layers at deposition rates of “4800 Å/min or more” (col. 1, ll.
13-15 and 36-65).
2. Ryu teaches, however, that such prior art deposition rates of
“4800 Å/min or more” create problems in terms of voids in the
context of smaller devices and increased circuit densities (col.
1, l. 62 to col. 2, l. 20).
3. To avoid the problem of voids in the prior art and to provide
other advantages, Ryu describes depositing (either by thermal
or plasma CVD) a passivation layer of fluorine-doped silicon
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oxide at a rate less than about 4500 Å/min (but preferably
above about 3000 Å/min) (col. 3, ll. 12-23; col. 5, ll. 1-3).
4. Ryu does not disclose deposition rates on the order of about
8000 Å/min.
5. Ryu does not indicate to one skilled in the relevant art that a
deposition rate on the order of about 8,000 Å/min is included
within “4800 Å/min or more.”
6. Ryu teaches that passivation layers based on
triethoxyfluorosilane (TEFS) may be deposited using TEFS,
tetraethoxyorthosilicate (TEOS), oxygen, and helium (as a
carrier gas) but that “[o]ther gases may be used in place of those
listed (e.g., ozone (O3) may be used in place of oxygen)” (col.
4, ll. 4-15; col. 12, ll. 28-31).
7. Vassiliev teaches that “methods such as plasma enhanced
deposition must not be incorporated even though they may offer
some short term advantages such as higher deposition rates”
(col. 6, ll. 4-9).
8. Vassiliev does not disclose any specific deposition rate in
connection with “higher deposition rates.”
9. Kirchhoff teaches that dopants such as boron and phosphorus
may be used in the formation of insulating materials (col. 3, ll.
34-48).

PRINCIPLES OF LAW
“Section 103 forbids issuance of a patent when ‘the differences
between the subject matter sought to be patented and the prior art are such
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that the subject matter as a whole would have been obvious at the time the
invention was made to a person having ordinary skill in the art to which said
subject matter pertains.’” KSR Int’l Co. v. Teleflex, Inc., 550 U.S. 398, 406
(2007).
KSR reaffirms the analytical framework set out in Graham v. John
Deere Co., 383 U.S. 1 (1966), which states that an objective obviousness
analysis includes: (1) determining the scope and content of the prior art; (2)
ascertaining the differences between the prior art and the claims at issue; and
(3) resolving the level of ordinary skill in the pertinent art. KSR, 550 U.S. at
407. Secondary considerations such as commercial success, long felt but
unsolved needs, or failure of others “might be utilized to give light to the
circumstances surrounding the origin of the subject matter sought to be
patented.” Id. (quoting Graham, 383 U.S. at 17-18).
While KSR explains that an obviousness “analysis need not seek out
precise [prior art] teachings,” it nonetheless did not dispense with the need
for evaluating the evidence to determine whether a person having ordinary
skill in the art would have had “an apparent reason to” arrive at the claimed
subject matter. Id., 550 U.S. at 418.

ANALYSIS
As already indicated, the first issue identified above turns on whether
the Examiner has identified “an apparent reason” to modify Ryu by
increasing the deposition rate from less than about 4500 Å/min to about
8000 Å/min as recited in independent claims 43, 63, and 74. KSR, 550 U.S.
at 418. The second and third issues turn on whether the Examiner has
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identified “an apparent reason” to modify Ryu by using a mixture of about 5
to about 15 vol% of ozone in O2 as recited in claims 67 and 74. Id.

Deposition Rate
We agree with Appellants that the Examiner failed to establish a
prima facie case of obviousness (Br. 10). Ryu teaches deposition rates less
than about 4500 Å/min because prior art deposition rates on the order of
“4800 Å/min or more” were found to cause undesirable voids (Facts 1-3).
Ryu’s teaching concerning the use of lower deposition rates applies for both
thermal and plasma-enhanced CVD processes (Fact 3). Thus, in contrast to
the subject matter of claims 43, 63, and 74, Ryu does not disclose a
deposition rate on the order of about 8000 Å/min (Fact 4).
In an attempt to account for the difference (in terms of deposition
rates) between Ryu and the claimed subject matter, the Examiner advanced
two principal theories. The first theory underlying the Examiner’s
obviousness conclusion is that Appellants did not demonstrate criticality for
the deposition rates recited in the claims (Ans. 4). This reasoning, however,
is insufficient to make out a prima facie case of obviousness in the first
instance. Contrary to the Examiner’s stated position, Appellants are not
required to demonstrate any criticality unless a prima facie case of
obviousness has been established. In re Oetiker, 977 F.2d 1443, 1445 (Fed.
Cir. 1992) (“If examination at the initial stage does not produce a prima
facie case of unpatentability, then without more the applicant is entitled to
the grant of a patent.”).
The Examiner’s second theory is that Vassiliev would have suggested
higher deposition rates with the practice of plasma-enhanced deposition
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(Ans. 4-5). This theory is also misplaced. Vassiliev actually teaches that
“methods such as plasma enhanced deposition must not be incorporated
even though they may offer some short term advantages such as higher
deposition rates” (Fact 7). While Vassiliev may suggest that plasma
enhanced deposition processes may be performed at “higher deposition
rates” relative to thermal deposition, Vassiliev does not quantify the “higher
deposition rates” (Fact 8). Furthermore, Vassiliev’s teaching does not
negate Ryu’s requirement that the deposition rate must be maintained below
about 4500 Å/min regardless of whether thermal or plasma-enhanced
deposition is used (Fact 3).
Neither of the applied prior art references discloses the use of a
deposition rate on the order of about 8000 Å/min (Facts 4 and 8). While
Ryu’s discussion of inferior prior art processes in which the deposition rates
were “4800 Å/min or more” might have arguably prompted a person skilled
in the art to try a deposition rate on the order of about 5000 Å/min, the
Examiner failed to direct us to any evidence or acceptable reasoning to
compel a conclusion that a person having ordinary skill in the art would have
modified Ryu’s process by increasing the deposition rate to rates
significantly higher than about 4800 Å/min, such as about 8000 Å/min as
required by claims 43, 63, and 74. In re Sebek, 465 F.2d 904, 907 (CCPA
1972) (“Where, as here, the prior art disclosure suggests the outer limits of
the range of suitable values, and that the optimum resides within that range,
and where there are indications elsewhere that in fact the optimum should be
sought within that range, the determination of optimum values outside that
range may not be obvious.”).

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Use of a Mixture of Ozone and Oxygen in Specific Amounts
We also find no merit in the Examiner’s position with respect to the
recited “mixture of from about 5 [vol]% to about 15 [vol%] ozone in O2” in
claims 67 and 74 (Ans. 13). Again, the Examiner’s obviousness conclusion
is premised on the finding that Appellants did not show criticality for the
claimed relative amounts (id.). But, as we discussed earlier, Appellants are
not required to demonstrate any criticality unless a prima facie case of
obviousness has been established. Oetiker, 977 F.2d at 1445.
Because the Examiner’s obviousness conclusion is infected by the
Examiner’s erroneous reasoning, we cannot affirm the Examiner’s rejection
as stated in the record.

CONCLUSION
On this record, we determine that Appellants have shown that the
Examiner reversibly erred in concluding that:
a person having ordinary skill in the art would have had a reason to
increase Ryu’s disclosed deposition rate of less than about 4500 Å/min to
“about 8000” or “8000” Å/min as recited in independent claims 43, 63, and
74; and
a person having ordinary skill in the art would have had a reason to
use a mixture of about 5 to about 15 vol% of ozone in O2 as recited in claims
67 and 74.

DECISION
The Examiner’s decision to reject
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claims 43-49, 54, 55, 62-66, 74, and 75 under 35 U.S.C. § 103(a) as
unpatentable over Ryu in view of Vassiliev,
claims 67-69, 71, and 72 under 35 U.S.C. § 103(a) as unpatentable
over Ryu,
claim 70 under 35 U.S.C. § 103(a) as unpatentable over Ryu in view
of Vassiliev,
claims 50-53 and 56-61 under 35 U.S.C. § 103(a) as unpatentable over
Ryu, Vassiliev, and Kirchhoff, and
claims 73 and 76 under 35 U.S.C. § 103(a) as unpatentable over Ryu
in view of Kirchhoff,
is reversed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1).
REVERSED

sss

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