Ex Parte Cheng

Board of Patent Appeals and Interferences

Feb 23, 2009

10908722 (B.P.A.I. Feb. 23, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte KANGGUO CHENG
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Appeal 2008-6197
Application 10/908,722
Technology Center 2800
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Decided:1 February 23, 2009
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Before EDWARD C. KIMLIN, CHUNG K. PAK, and
LINDA M. GAUDETTE, Administrative Patent Judges.

GAUDETTE, Administrative Patent Judge.

DECISION ON APPEAL

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 2008-6197
Application 10/908,722

Appellant appeals under 35 U.S.C. § 134(a) from the Examiner’s
decision finally rejecting claims 1-4, 6-12, 22, and 23 (Final Office Action,
mailed Sept. 20, 2006), the only claims pending in the application. We have
jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.
STATEMENT OF THE CASE
Claim 1, the sole independent claim, is illustrative of the subject
matter on appeal, and is reproduced from Appendix B to the Amended
Appeal Brief2:
1. A method of forming a semiconductor wafer having a device layer
of semiconductor separated from a substrate layer by a separation layer of
insulator comprising the steps of:

providing first and second semiconductor wafers, each having a
bonding surface;

forming a layer of bonding insulator on at least one of said bonding
surfaces;

incorporating deuterium [in] said layer of bonding insulator;

bonding said wafers at said layer of bonding insulator, thereby
forming a separation layer from said layer of bonding insulator; and

forming a device layer in one of said first and second semiconductor
wafers.

Appellant requests review of the following grounds of rejection
(Amended Appeal Brief (“Br.”), filed July 9, 2007, 3):

2 (See Ans. 2, § (4) (noting entry of Appellant’s amendment after final
rejection, filed Feb. 20, 2007).)
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Application 10/908,722

1. claims 1, 2, 4, 7, 9, and 11 under 35 U.S.C. § 103(a) as
unpatentable over Henley in view of Moriceau;
2. claims 3, 10, and 12 under 35 U.S.C. § 103(a) as unpatentable
over Henley in view of Moriceau and further in view of Usenko;
3. claims 6 and 22 under 35 U.S.C. § 103(a) as unpatentable over
Henley in view of Moriceau and further in view of Lyding;
4. claim 8 under 35 U.S.C. § 103(a) as unpatentable over Henley
in view of Moriceau and Lyding and further in view of Usenko; and
5. claim 23 under 35 U.S.C. § 103(a) as unpatentable over Henley
in view of Moriceau and further in view of Jiang.

ISSUE
Has Appellant shown reversible error in the Examiner’s determination
that it would have been obvious to have replaced the particles implanted in
Henley’s gettering layer with deuterium, based on Moriceau’s disclosure?
We answer this question in the negative.
FINDINGS OF FACT (“FF”)
1. Henley discloses a process in which a silicon wafer substrate is
joined to a workpiece (col. 6, ll. 49-50), such as a silicon wafer (col. 6, ll.
56-57). Henley discloses an embodiment in which at least one of the wafers
includes a gettering layer comprising particles implanted into an insulating
layer on a surface which is to be joined to the other wafer (col. 6, ll. 28-32
and 58-61). According to Henley, the particles can include a variety of
materials which either form gas bubbles or implanted precipitates (col. 6, ll.
33-35), such as “helium, neon, argon, krypton, and xenon” (col. 5, ll. 26-28).
The microbubbles or implanted precipitates act as gettering (i.e., trapping
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Appeal 2008-6197
Application 10/908,722

(see col. 5, ll. 29-30; 40-41)) sites for impurities (col. 2, ll. 42-45). Henley
also discloses that “hydrogen ions” and ions formed from noble gases, may
be implanted into a silicon region of a bonded structure, to form a gettering
layer (col. 10, ll. 20-37).
2. Moriceau discloses a method for producing a multilayer
structure by molecular adhesion techniques (col. 1, ll. 6-8), i.e., wafer
bonding (col. 1, l. 22). “[T]he invention more specifically relates to a
method for producing a multilayer structure comprising at least a first and
second layers called main layers, connected with each other by a stack of at
least two stress adaptation layers and having a determined structure stress”
(col. 4, ll. 25-30).
3. Moriceau discloses that a known technique for making of a
fracture area in a layer is by implantation of a gas species able to generate an
embrittled layer formed of microcavities or gas microbubbles (col. 6, ll. 30-
35). Moriceau defines a “microcavity or gas microbubble” as “any cavity
generated by implantation of hydrogen gas and/or rare gas ions in the
material” (col. 6, ll. 36-38). Moriceau identifies exemplary gas species as
“hydrogen or rare gases in their atomic form (for example H), or in their
molecular form (for example H2) or in their ion form (for example H+, H2+)
or in their isotope form (for example deuterium) or isotope and ion form”
(col. 6, ll. 48-52).
4. The Examiner finds that Henley discloses the invention as
claimed with the exception of an express disclosure of incorporating
deuterium in the layer of bonding insulator. (Ans. 4.) The Examiner notes
that Henley does, however, specifically disclose using hydrogen ions and
noble gases to form implanted precipitates or gas bubbles to act as gettering
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Appeal 2008-6197
Application 10/908,722

sites. (Ans. 4.) The Examiner further notes that Moriceau teaches that gas
bubbles may be formed in semiconductor layers by implanting hydrogen gas
and/or rare gas ions, as well as deuterium, the isotope form of hydrogen gas.
(Ans. 4.) The Examiner thus concludes that one of ordinary skill in the art at
the time of the invention would have had a reasonable expectation of success
in implanting deuterium in Henley’s insulating layer to form a gettering
layer based on Moriceau’s disclosure that deuterium forms microbubbles in
the same manner as the gases used by Henley to form gas bubbles or
implanted precipitates. (Ans. 5.)
5. Appellant concedes that Henley discloses the implantation of
hydrogen, but argues that Henley does not explicitly disclose implanting
hydrogen in the context of forming a gettering layer prior to forming an SOI
bonded structure. (Br. 4.) More specifically, Appellant argues that Henley
only discloses the use of “hydrogen as a getter which is implanted into a
silicon region after formation of the SOI bonded structure” (Br. 4).
Appellant also concedes that Moriceau discloses the implantation of
hydrogen, but argues that the hydrogen implant is not intended to form part
of the resulting semiconductor-on-insulator (“SOI”) structure. (Br. 5.)
Appellant further argues that neither Usenko, Lyding, nor Jiang discloses or
suggests formation of SOI wafers or placement of deuterium in the insulator
layer used to bond the initial wafers used for forming SOI wafers. (Br. 5-8
(discussing Grounds of Rejection 2-5).) Appellant thus contends that the
combined teachings of Henley and Moriceau, alone or as further modified in
view of Usenko, Lyding and/or Jiang, would not result in a process in which
“deuterium is incorporated in at least one of said layers of bonding insulator
as required by the present claims.” (Br. 5, 6, and 7-8.)
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Appeal 2008-6197
Application 10/908,722

PRINCIPLES OF LAW
“The combination of familiar elements according to known methods
is likely to be obvious when it does no more than yield predictable results.”
KSR Int’l Co. v. Teleflex Inc., 127 S. Ct. 1727, 1739 (2007). The question to
be asked is “whether the improvement is more than the predictable use of
prior art elements according to their established functions.” Id. at 1740. In
considering the question of the obviousness of a claimed invention in view
of the prior art relied upon, we are guided by the basic principle that the
question under 35 U.S.C. § 103 is not merely what the references expressly
teach but what they would have suggested to one of ordinary skill in the art
at the time of the invention. See Merck & Co., Inc. v. Biocraft Labs., Inc.,
874 F.2d 804, 807-08 (Fed. Cir. 1989); In re Keller, 642 F.2d 413, 425
(CCPA 1981) (“The test for obviousness is not . . . that the claimed
invention must be expressly suggested in any one or all of the references.”).
“For obviousness under § 103, all that is required is a reasonable expectation
of success.” In re O’Farrell, 853 F.2d 894, 903-04 (Fed. Cir. 1988)
(citations omitted).
ANALYSIS
We are not persuaded of reversible error on the part of the Examiner
because Appellant has not addressed the facts and reasons relied on by the
Examiner in rejecting the claims.
Appellant’s traversal of the Examiner’s rejections is based on a
contention that modification of Henley’s method in view of Moriceau would
not result in the claimed invention, because Moriceau’s implantation step
serves a different purposed than Henley’s implantation step. In particular,
Appellant points out that Moriceau’s implanted particles are not intended to
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Application 10/908,722

form part of the resulting SOI structure, whereas Henley’s particles do form
part of the final structure. However, the Examiner’s rejection is not based
on a determination that it would have been obvious to have replaced
Henley’s implantation step with Moriceau’s, e.g., to form a fracture layer in
Henley’s structure. Rather, the Examiner’s rejection is based on a
determination that it would have been obvious to have replaced the particles
explicitly disclosed by Henley as useful in forming a gettering layer with
deuterium based on Moriceau’s teaching of using deuterium to form
microbubbles, the same result achieved by Henley’s particles. Appellant has
not explained why the Examiner erred in finding that one of ordinary skill in
the art would have had a reasonable expectation of success in using
deuterium in Henley’s implanting step to form a gettering layer based on
Moriceau’s teaching of equivalence of deuterium and Henley’s particles in
forming microbubbles.
Because Appellant has not addressed the Examiner’s rationale for
rejecting the claims, Appellant has not shown that the Examiner reversibly
erred.
CONCLUSION
Appellant has not identified reversible error in the Examiner’s
obviousness determination. The decision of the Examiner rejecting claims
1-4, 6-12, 22, and 23 is affirmed.

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Appeal 2008-6197
Application 10/908,722

No time period for taking any subsequent action in connection with
this appeal maybe extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED

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