Ex Parte Lee et al

Patent Trial and Appeal Board

Oct 26, 2018

14293221 (P.T.A.B. Oct. 26, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
14/293,221 06/02/2014
81088 7590 10/30/2018
WOMBLE BOND DICKINSON (US) LLP / FIJI
Attn: IP Docketing
P.O. Box 7037
Atlanta, GA 30357-0037
Lie-Quan Lee
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.
8536P023 5279
EXAMINER
STIFTER JR, TERENCE E
ART UNIT PAPER NUMBER
2865
NOTIFICATION DATE DELIVERY MODE
10/30/2018 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):
FIP _Group@bstz.com
PTO.MAIL@BSTZPTO.COM
PTO.MAIL@BSTZ.COM
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte LIE-QUAN LEE, 1
LEONID POSLA VSKY, and STILIAN IVANOV P AND EV
Appeal 2018-006282
Application 14/293 ,221
Technology Center 2800
Before MARK NAGUMO, GEORGE C. BEST, and
N. WHITNEY WILSON, Administrative Patent Judges.
NAGUMO, Administrative Patent Judge.
DECISION ON APPEAL
Lie-Quan Lee, Leonid Poslavsky, and Stilian Ivanov Pandev ("Lee")
timely appeal under 35 U.S.C. § 134(a) from the Final Rejection2 of all
pending claims 1-6, 8-10, 12-20, 22-24, 26, and 28-30 as being drawn to
judicially excepted subject matter. We have jurisdiction. 35 U.S.C. § 6.
We affirm.
1 The real party in interest is identified as KLA-Tencor Corporation.
(Appeal Brief, filed 21 November 2017 ("Br."), 3.)
2 Office Action mailed 24 February 2017 ("Final Rejection"; cited as "FR").
Appeal 2018-006282
Application 14/293 ,221
A. Introduction 3, 4, 5
OPINION
The subject matter on appeal is said to relate to the dynamic removal
of highly correlated parameters for optical metrology. (Spec. 1, [0002].)
According to the '221 Specification, algorithms such as the rigorous
coupled wave analysis (RCW A) are widely used "for the study and design of
diffraction structures." (Id. at [0003].) In these methods, the profiles of
periodic structures are said to be "approximated by a given number of
sufficiently thin planar grating slabs." (Id.) In addition to material-specific
parameters, such as "the refractive index or n, k values" (id. at 29 [0096]),
geometric parameters such as thicknesses, critical dimension, sidewall angle,
height, edge roughness, comer rounding radius, etc., may be used to
characterize the shape of the features being measured (id. at 30 [0097]). The
Specification indicates that 30-50 or more of such parameters may go into
the model of a two- or three6-dimensional element. (Id.) Simulated spectra
3 Application 14/293 ,221, Dynamic removal of correlation of highly
correlated parameters for optical metro logy, filed 2 June 2014, claiming the
benefit of a provisional application filed 3 June 2013. We refer to the
"'221 Specification," which we cite as "Spec."
4 Because this application claims the benefit of a preliminary application
filed after the 16 March 2013, effective date of the America Invents Act, we
refer to the AIA version of the statute.
5 A petition to make special under Patent Prosecution Highway,
filed 12 January 2015, was granted on 17 June 2015.
6 In addition to repeated variation in height ( along the z-axis ), the grating
may vary along the x-axis (e.g., rows of ridges; see Figure 6B,
two-dimensional grating) or along both the x- and y-axes (e.g., rows and
columns of blocks; see Figure 6A, three-dimensional grating).
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Application 14/293 ,221
for a periodic structure may be calculated by RCW A for such a model,
followed by regression analysis to fit the model to a measured diffraction
spectrum of the structure from which the model was generated.
(Id. at [0098].)
The Specification, however, teaches that many parameters may be
highly correlated, by which the Specification means they are "correlated to
any degree that may interfere with an operation." (Id. at 9 [0027].)
In particular, during optimization of parameters to fit the model to the
measured structure, the search directions for model optimization may
become unstable because "the change of an objective function due to one
parameter can be largely compensated by changes of its highly correlated
parameter ( or parameter set)" (id. at [0030]), resulting in toggling
(id. at [0029]) and lack of convergence. A difficulty with prior art methods
of addressing this problem is said to be the "re-parameterization" of the
model, resulting in floating parameters that are abstract and that have no
physical meaning. (Id. at 11-12 [0038].) As a result, "there may be no easy
way to intuitively manipulate such abstract parameters." (Id. at 12.)
The Specification discloses methods that are said to simplify the
problem without changing the model, in particular, without altering the
parameters that are to be modified to arrive at an optimized fit of the
calculated properties of the model to the values measured from the physical
device. 7
7 The mathematically inclined reader is directed to the discussion in the
Specification at page 10, paragraph [0033-page 14, paragraph [0050] for a
more technical discussion. Very briefly, when parameters are highly
correlated, a certain n x n H matrix ("Hessian") of second order partial
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Application 14/293 ,221
Claim 1 is representative and reads:
A method for optical metro logy testing of a microelectronic
structure comprising:
determining a model of a first microelectronic structure
on a substrate, the model of the first microelectronic
structure including a set of model parameters, the set of
model parameters including
geometric parameters, material parameters, or both;
performing optical metro logy measurement of the first
microelectronic structure utilizing
an optical metro logy system to determine a value of at
least one parameter of the first microelectronic structure,
including collecting measured spectra data for the first
microelectronic structure on a hardware element,
the hardware element being a reflectometer or
ellipsometer;
during the optical metro logy measurement of the first
microelectronic structure,
dynamically removing correlation of two or more
parameters of the set of model parameters,
wherein the dynamic removal of correlation of
parameters during the optical metrology
measurement does not change the model of the
microelectronic structure,
each iteration of the dynamic removal of correlation
during the optical metrology measurement including:
derivatives is said to be often close to singular-i.e., without an inverse-
leading to large errors and failure to converge on a global minimum. Under
certain conditions (Spec. 13 [0046]-14 [0050]), the complexity of the
mathematical problem may be reduced by applying constraints to reduce the
size of the parameter set (id. at 13 [0045]), thereby "eliminating (throwing
away) certain search directions that do not significantly change the objective
function values when change is along one or combination of those
directions" (id. at 16 [0061 ]).
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Application 14/293 ,221
generating a Jacobian matrix of the set of model
parameters, wherein generating the matrix includes
inputting the measured spectra data for the
microelectronic structure collected by the
hardware element,
applying a singular value decomposition of the
Jacobian matrix, wherein
the application of the singular value
decomposition results in a set of singular vectors,
selecting a subset of the set of singular vectors, wherein
selecting the subset of vectors includes
applying a threshold, the threshold being adaptively
selected based on the number of iterations of the
dynamic removal of correlation that are performed,
and
computing a direction of the parameter search based
on the subset of vectors;
if the model of the first microelectronic structure does
not converge following an iteration of the dynamic
removal of correlation,
peiforming one or more additional iterations of the
dynamic removal of correlation until the model
converges; and
if the model of the first microelectronic structure does
converge, reporting out results of the optical metro logy
measurement of the first microelectronic structure including
the value of the at least one parameter of the first
microelectronic structure based on comparison of the
measured spectra data for the first microelectronic
structure with a simulated diffraction signal for the model
of the first microelectronic structure.
(Claims App., Br. 27-28; some indentation, paragraphing, and emphasis
added.)
Independent claim 15 is directed to a "non-transitory tangible
machine-accessible storage medium having instructions" that cause the
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Application 14/293 ,221
method to be carried out. (Id. at 29--30.) Remaining independent claim 29
is directed to a system for optical metro logy testing of microelectronic
structures for carrying out the method. (Id. at 32-33.)
B. Discussion
The Board's findings of fact throughout this Opinion are supported by
a preponderance of the evidence of record.
Initially, we find that Lee's arguments for the patentability of claim 15
(Br. 14--20) and for the patentability of claim 29 (id. at 20-26) are
substantially the same as the arguments for patentability of claim 1
(id. at 10-14). Moreover, Lee expressly limits arguments for patentability of
the corresponding dependent claims to those raised for the independent
claims. (Id. at 26.) We therefore focus our attention on claim 1, with which
the remaining claims stand or fall. 37 C.F .R. § 41.37 ( c )(1 )(iv) (2017).
Lee (Br. 10, 11. 15-20) urges that the Examiner erred harmfully in
step 1 of the Alice analytical framework by concluding that the claimed
invention is "directed to an abstract idea of a method for dynamic removal of
correlation of parameters" (FR 5, 11. 3--4), more specifically, "to an
algorithm for performing a series of mathematical operations/functions to a
model that includes a set of parameters" (id. at 24--25). Rather than being
analogous to the patent-ineligible inventions at issue in Maucorps 8
( algorithm for determining an optimum number or value) and Flook9
(formula for computing an alarm limit) (Br. 10), Lee urges that the claimed
8 In re Maucorps, 609 F.2d 481 (CCPA 1979).
9 Parker v. Flook, 437 U.S. 584 (1978).
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Application 14/293 ,221
invention is analogous to the patent-eligible claim at issue in Diehr10
because the steps of the claimed process "impose meaningful limits that
apply the formula to improve an existing technological process" (id. at 11 ).
Moreover, Lee argues, "the claim is inextricably tied to optical metrology."
(Id.) In Lee's view, as inMcR0 11 , "claim 1 provides for specific rules in a
process for automated optical metro logy testing of microelectronic structure
to achieve an improved technological result, and specifically for determining
and presenting a value of at least one parameter of the first microelectronic
structure." (Id. at 13, 11. 14--17.)
These arguments are not persuasive of harmful error. That the
claimed process involves performing optical measurements on a first
microelectronic structure is not dispositive. As the Court held in Flook,
"a claim for an improved method of calculation, even when tied to a specific
end use, is unpatentable subject matter under§ 101." 437 U.S. at 595 n.18;
cf Bancorp Servs., L.L.C. v. Sun Life Assur. Co. of Canada (US), 687 F.3d
1266, 1277 (Fed. Cir. 2012) ("a machine, system, medium, or the like may
in some cases be equivalent to an abstract mental process for purposes of
patent ineligibility. As the Supreme Court has explained, the form of the
claims should not trump basic issues of patentability" ( citing, inter alia,
Flook, 437 U.S. at 593)). As for the steps of processing the measured data,
although an allegedly novel combination of analytical steps is recited, our
reviewing court has explained that "we have treated analyzing information
10 Diamondv. Diehr, 450 U.S. 175 (1981).
11 McRO, Inc. v. Bandai Namco Games Am. Inc., 837 F.3d 1299 (Fed.
Cir. 2016).
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Application 14/293 ,221
by steps people go through in their minds, or by mathematical algorithms,
without more, as essentially mental processes within the abstract-idea
category." Elec. Power Grp., LLC v. Alstom S.A., 830 F.3d 1350, 1353-54
(Fed. Cir. 2016). As the court explained recently, "[i]t is clear from Mayo
that the 'inventive concept' cannot be the abstract idea itself, and
Berkheimer and Aatrix leave untouched the numerous cases from this court
which have held claims ineligible because the only alleged 'inventive
concept' is the abstract idea." Berkheimer v. HP Inc., 890 F.3d 1369, 1374
(Fed. Cir. 2018) (denying reh'g en bane) (citation omitted). Finally, the
result of the claimed process, upon convergence of the model, is "reporting
out results of the optical metro logy measurement ... including the value
of ... at least one parameter .... " Again, our reviewing court has explained
that "merely presenting the results of abstract processes of collecting and
analyzing information, without more ( such as identifying a particular tool for
presentation), is abstract as an ancillary part of such collection and analysis."
Elec. Power Grp., 830 F.3d at 1354. Thus, the final step of the claim is not
enough by itself to bring the claim into the realm of patent eligibility.
In McRO, the Federal Circuit determined that the rules incorporated
into the claimed process prevented the claim from being directed to an
abstract idea. The "rules with specific characteristics" at issue in McRO
involve "a first set of rules that define output morph weight set stream as a
function of phoneme sequence and time of said phoneme sequence." McRO,
837 F.3d at 1307---08, 1313. Broad as these rules are, they nonetheless
establish relations between physical events, namely, the facial expressions
people make when making a phoneme, i.e., a specific sound, the visual
representation of a character's face (a "viseme"), and a timed transcript of
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Application 14/293 ,221
the phonemes pronounced during an utterance. The result of the application
of these rules is a final stream of output morph weight sets at a desired frame
rate to produce lip synchronization and facial expression control of the
animated character speaking the utterance. As a result, the claims do not
"preempt approaches that use rules of a different structure or different
techniques." Id. at 1316. In contrast, the rules of the present claims involve
dynamically removing correlation of two or more parameters by generating
a Jacobean matrix, applying a singular value decomposition, and selecting,
by applying a threshold condition, a subset of the singular vectors until the
model converges. These purely mathematical operations are abstract ideas
applied to data ( optical measurements) obtained by ellipsometry or
reflectometry. The result of the calculations is the value of at least one
parameter of the structure. It cannot be said, fairly, that that value is an
improved technological result in an industrial practice, conventional or
otherwise.
We conclude that harmful error has not been demonstrated in the
Examiner's Alice step 1 analysis. We therefore tum to step 2 of the Alice
framework, in which we look for something in the claims, other than and in
addition to the abstract ideas, that transforms the abstract idea into patent-
eligible subject matter.
Lee urges that "the claim elements recite an improvement to the
technology of optical metrology testing of a microelectronic structure."
(Br. 14, 11. 12-14.) The improvement is said to be "dynamically removing
the correlation of model parameters during an optical metro logy
measurement without changing the model of the structure itself."
(Id. at 11. 19-20.) The dynamic removal process, however, is disclosed to be
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Application 14/293 ,221
a series of mathematical manipulations, and thus is a "mental process[]
within the abstract-idea category." Elec. Power Grp., 830 F.3d at 1354.
There is, moreover, neither in the claim nor in the supporting
disclosure, any indication that nonstandard processing hardware, or
nonstandard software ( aside from the specific coding for solving the sets of
equations) is presented as part of the claimed invention. Thus, there are no
additional elements which serve to transform the abstract idea into patent-
eligible subject matter.
We conclude that harmful error has not been demonstrated in the
appealed rejection.
C. Order
It is ORDERED that the rejection of claims 1---6, 8-10, 12-20, 22-24,
26, and 28-30 is affirmed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED
10