Ex Parte Chen et al

Patent Trial and Appeal Board

Jun 22, 2018

13371046 (P.T.A.B. Jun. 22, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
13/371,046 02/10/2012 Yuan-Hsuan Chen
95496 7590 06/26/2018
Hauptman Ham, LLP (TSMC)
2318 Mill Road
Suite 1400
Alexandria, VA 22314
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
T5057-R578 9968
EXAMINER
AU, BACH
ART UNIT PAPER NUMBER
2822
NOTIFICATION DATE DELIVERY MODE
06/26/2018 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address( es):
tsmc@ipfirm.com
sramunto@ipfirm.com
pair_lhhb@firsttofile.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte YUAN-HSUAN CHEN, KEI-WEI CHEN,
YING-LANG WANG, and KUO-HSIU WEI
Appeal2017-008251
Application 13/371,046 1
Technology Center 2800
Before KAREN M. HASTINGS, N. WHITNEY WILSON, and
SHELDON M. McGEE, Administrative Patent Judges.
Opinion of the Board by McGEE, Administrative Patent Judge.
Opinion dissenting by HASTINGS, Administrative Patent Judge
DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134, Appellants seek our review of the
Examiner's rejections under 35 U.S.C. § 103(a) of claims 11-30.
We have jurisdiction under 35 U.S.C. § 6.
We reverse.
1 The real party in interest is identified as Taiwan Semiconductor
Manufacturing Company, Ltd. App. Br. 2.
Appeal2017-008251
Application 13/371,046
BACKGROUND
The subject matter on appeal relates to methods of thinning one or
more wafers used, for example, in cameras containing optical sensors. Spec.
i-f 1; Claims 11, 21, and 27.
Independent claim 11 is illustrative of the claimed subject matter and
appears below (with key limitations italicized):
11. A method of thinning a wafer comprising:
measuring an initial thickness of the wafer;
calculating a polishing time using a material removal rate,
a predetermined thickness and the initial thickness;
polishing the wafer for a first duration equal to the
polishing time to obtain a polished wafer;
measuring a polished thickness of the polished wafer; and
updating the material removal rate based on the
predetermined thickness, the polishing time and the polished
thickness.
App. Br. 17 (emphasis added).
The Examiner rejects claims 11, 12, 14, and 16-30 under 35 U.S.C.
§ 103(a) as obvious over Hu2 in view ofRavid. 3 Final 2-7. Claims 13 and
15 are likewise rejected as obvious over these references in view of Matsui. 4
Final 7-8.
STATEMENT OF THE CASE
Relevant to this appeal, the Examiner finds that Hu discloses in
Figures 1 and 2 both "measuring an initial thickness of the wafer," and then
calculating or determining a polishing time based, inter alia, on such
measured initial thickness, as recited in each of the independent claims 11,
2 Hu et al., US 2007/0082490 Al, published Apr. 12, 2007.
3 Ravid et al., US 2007/0123046 Al, published May 31, 2007.
4 Matsui et al., US 6,191,007 Bl, issued Feb. 20, 2001.
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Application 13/371,046
21, and 27. Final 2-3. The Examiner alternatively finds that the recited
measuring step is inherently disclosed by Hu because "the process disclosed
by Hu necessarily requires that an initial thickness is known in order to
know how much of the wafer is polished with the first polishing process
(step 102)." Ans. 10. See also Ans. 12 citing Hu i-f 28. Although the
Examiner finds that Hu discloses "measuring an initial thickness of the
wafer," the Examiner finds further that Ravid discloses "more specifically
the steps of measuring an initial thickness [to, ti] and a polished thickness."
Final 4.
OPINION
We begin with claim construction, affording the disputed claim term
"measuring an initial thickness of the wafer" its broadest reasonable
interpretation consistent with the Specification. In re Hyatt, 211F.3d1367,
1372 (Fed. Cir. 2000) ("[D]uring examination proceedings, claims are given
their broadest reasonable interpretation consistent with the specification.")
Figures IA and IB of the Specification are depicted below.
:~J
1CZo ':ii2h ./
T 1'! .. lmmmmmmmmmmmmmmmL-.f_.:,~
1 ~ ~02
._____ --~'1-0~
FIG.1A
FIG, 1B
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Appeal2017-008251
Application 13/371,046
Figure IA illustrates a side view of a wafer assembly 100 prior to a
polishing process, while Figure 1 B depicts wafer assembly 100 after such
polishing. Spec. i-fi-f 11, 16. Prior to polishing, the wafer layer 102 has an
"initial thickness, Ti." Spec. i-f 11. After polishing, wafer layer 102 has a
"polished thickness, T2, [which is] less than the initial thickness, Ti." Spec.
i-f 16. Wafer layer 102 thickness "is measured from exposed surface 102a, to
bonded surface 102b." Spec. i-fi-f 13, 19. A first metrology tool is configured
to measure initial thickness Ti of the wafer layer, and the initial thickness
value is transmitted to a controller. Spec. i122. The controller is configured
to calculate a polishing time based on, inter alia, initial thickness value Ti
and a desired predetermined or "target" thickness after the polishing process.
Spec. i-fi-130-31. The calculated polishing time is transmitted by the
controller to a polishing tool which polishes the wafer layer to a polished
thickness T2 as measured by a second metrology tool. Spec. i-fi-135, 36.
Based on the foregoing disclosure, we construe the recited "initial
thickness of the wafer" to be the wafer's thickness prior to any polishing
step. Applying this construction, we now tum to Appellants' contention that
neither Hu nor Ravid discloses a step of measuring an initial wafer thickness
as required by the independent claims. App. Br. 6-13. Specifically,
regarding Hu, Appellants urge that the Examiner "failed to reference any
specific paragraph or element of Hu" that evinces the recited measurement
of the wafer's initial thickness that occurs prior to the recited polishing step.
App. Br. 7. Appellants argue that, unlike the claimed invention, Ru's first
measurement occurs after the polishing step is completed, and is thus not an
"initial thickness" measurement. App. Br. 7. Appellants contend further
that, because Ru's first wafer measurement occurs after the wafer is
polished, Hu cannot calculate a polishing time that takes an "initial
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Appeal2017-008251
Application 13/371,046
thickness" measurement into account. App. Br. 7. Appellants also argue
that the Examiner has made contradictory statements whether Hu explicitly
discloses the "initial measurement." App. Br. 9.
Regarding Ravid, Appellants contend that the Examiner failed to
specifically identify the relied-upon portions of this reference that evince the
disputed limitation, and that "while Ravid mentions thickness t0 and t1,
Ravid fails to teach or suggest measuring these values." App. Br. 10-11.
Appellants also contend that the Examiner's position regarding whether
Ravid expressly or inherently teaches such measuring has shifted throughout
prosecution. App. Br. 11-12.
We are persuaded that Appellants have identified reversible error in
the rejection. Appellants are correct that Ru's first thickness measurement is
taken after polishing. Hu i-f 27. As such, Ru's first measurement cannot
reasonably be considered an "initial thickness" measurement as recited in
each independent claim. Furthermore, the Examiner's alternative finding
that Hu inherently discloses an initial thickness measurement (Ans. 10-12)
is insufficient to support a prima facie case of obviousness. Even assuming
the Examiner is correct (Ans. 12) that the wafer's pre-polish thickness is
inherently "measured" by virtue of it being "derived out about the metal
thickness having been removed in the first polishing step," (Hu i-f 28), the
Examiner does not adequately establish that such measurement of the
wafer's initial thickness is then used to calculate a polishing time based on
the initial thickness measurement, the material removal rate and a
predetermined (i.e., "target") thickness. Claim 11 requires "calculating a
polishing time using ... the initial thickness," and then a step of "polishing
the wafer for a first duration equal to the polishing time" (emphasis added).
At best, Ru's polishing time calculation (i.e., "the consuming time for the
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Appeal2017-008251
Application 13/371,046
polishing") disclosed in paragraph 28 would not be for "polishing the
[unpolished] wafer for a first duration" as recited in claim 11. Rather, Ru's
polishing time calculation would be for a subsequent (i.e., not the first)
polishing step. Furthermore, step 106 upon which the Examiner relies (Final
2, 3) does not even appear to discuss any predetermined or target thickness
in the calculation of a polishing time as required by claim 11. Thus, on this
record, we agree with Appellants that the Examiner has failed to establish
that Hu discloses the recited "initial thickness" measurement of an
unpolished wafer, and then using that measurement in calculating the recited
polishing time. Moreover, the Examiner has not explained why it would
have been obvious to modify the teachings of Hu to arrive at the presently
claimed subject matter.
We furthermore agree with Appellants that there is no evidence that
Ravid measures the pre-polish (i.e., "initial") thicknesses t0 and t1. Rather,
the portions of Ravid upon which the Examiner relies (Final 4) suggest that
the measurements take place only after wafer polishing. Specifically, Ravid
indicates that "a first wafer is subject to the polishing steps of a CMP
process and one or more properties of the first wafer are measured," for
example in "an in-line metrology station." Ravid i-f 8. Such measurements
appear to be taken only after the wafer has been polished and transferred to
the metro logy station. See i-fi-1 25-26 (discussing how unpolished wafer 353
is taken from storage 313, placed in transfer station 383, subjected to
polishing in three polishing stations 393a, 393b, 393c, moved to cleaner 373,
and "[t]he robot 363 then can transfer the wafer 353 to and from the
metro logy station 323 [which] has the ability to measure one or more
properties of polishing" (emphasis added)). On this record, the Examiner
has failed to identify sufficient disclosure in Ravid that establishes that an
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Application 13/371,046
initial wafer thickness measurement is taken prior to a polishing step as
recited in the independent claims, or otherwise would have been obvious.
Because each of the obviousness rejections rely on an erroneous
finding that both Hu and Ravid disclose measuring a wafer's "initial
thickness," and, by extension, a "calculating" step that uses such initial
thickness measurement, we reverse the rejections.
DECISION
The decision of the Examiner is reversed.
REVERSED
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Appeal2017-008251
Application 13/371,046
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte YUAN-HSUAN CHEN, KEI-WEI CHEN,
YING-LANG WANG, and KUO-HSIU WEI
Appeal2017-008251
Application 13/371,046
Technology Center 2800
Before KAREN M. HASTINGS, N. WHITNEY WILSON, and
SHELDON M. McGEE, Administrative Patent Judges.
HASTINGS, Administrative Patent Judge, dissenting.
I respectfully dissent. Specifically, I disagree with my colleagues'
view that the Examiner has not sufficiently explained why the recited subject
matter, specifically taking a measurement of the thickness before a first
polishing step, would have been obvious.
I believe that one of ordinary skill in the art, using no more than
ordinary creativity, would have practiced the invention as set out in claim 11
(as well as independent claims 21 and 27). A person of ordinary skill in the
art would have readily appreciated that the initial thickness of the wafer was
measured at some point as de facto explained by the Examiner (e.g., Ans.
12).
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Application 13/371,046
In my view, Appellants have not persuasively disputed the Examiner's
determination that one of ordinary skill in the art, using no more than
ordinary creativity, based on the disclosures of Hu (with or without Ravid),
would have used an initial thickness of the wafer to determine how long to
polish the wafer as recited in claim 11. KSR Int 'l Co. v. Teleflex Inc., 550
U.S. 398, 418 (2007) ("[T]he analysis need not seek out precise teachings
directed to the specific subject matter of the challenged claim, for a court
can take account of the inferences and creative steps that a person of
ordinary skill in the art would employ."); See also id., at 421 ("A person of
ordinary skill is also a person of ordinary creativity, not an automaton."); In
re Fritch, 972 F.2d 1260, 1264---65 (Fed. Cir. 1992) (It is well settled that a
reference stands for all of the specific teachings thereof as well as the
inferences one of ordinary skill in this art would have reasonably been
expected to draw therefrom).
For these reasons and those set forth in the Examiner's Answer, I
believe that the Appellants' arguments do not identify a reversible error in
the Examiner's rejection of claim 11 (as well as independent claims 21 and
27). The Appellants do not provide any argument in support of the separate
patentability of claims 2-30. Appeal Br. 13-15.
As a result, I would have upheld the Examiner's§ 103 rejections.
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