Ex Parte Brown

Board of Patent Appeals and Interferences

Jul 31, 2008

10715267 (B.P.A.I. Jul. 31, 2008)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte NATHAN R. BROWN
__________

Appeal 2008-3352
Application 10/715,267
Technology Center 1700
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Decided: July 31, 2008
____________

Before PETER F. KRATZ, CATHERINE Q. TIMM, and
MICHAEL P. COLAIANNI, Administrative Patent Judges.

COLAIANNI, Administrative Patent Judge.

DECISION ON APPEAL
Appellant appeals under 35 U.S.C. § 134 the final rejection of claims
1, and 3-31. We have jurisdiction over the appeal pursuant to 35 U.S.C. §
6(b).
We AFFIRM.

INTRODUCTION
Appellant claims a method of polishing or planarizing a surface of a
semiconductor device structure comprising, in relevant part, “biasing
independently movable pressurization structures to selectively apply a
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Application 10/715,267

plurality of different amounts of pressure to different, selected locations of a
backside of the semiconductor device structure” (claim 1). By controlling
the amount of force applied based on the difference in height between the
raised and lower areas on the active surface of the semiconductor device, a
substantially constant material removal rate across the entire surface is
achieved to form a substantially planar surface on the semiconductor device
structure during polishing (Spec. ¶ [0010]).
Claims 1, 3, and 16 are illustrative:
1. A method for polishing or planarizing a surface of a
semiconductor device structure, comprising:
biasing independently movable pressurization structures to selectively
apply a plurality of different amounts of pressure to different, selected
locations of a backside of the semiconductor devices structure; and
polishing or planarizing at least one layer on the surface of the
semiconductor device structure.

3. The method of claim 1, wherein biasing comprises magnetically
biasing at least one of the independently movable pressurization structures
against the backside.

16. A method for polishing at least one layer on a semiconductor
device structure, comprising:
polishing at least one layer of a first semiconductor device structure;
locating any raised areas on the first semiconductor device structure
following the polishing;
selectively applying pressure to a backside of at least one second
semiconductor device structure of a same type as the first semiconductor
device structure, the selectively applying being effected at locations beneath
areas of the at least one second semiconductor device structure that
correspond to the raised areas of the first semiconductor device structure;
and
at least mechanically polishing at least one layer of the at least one
second semiconductor device structure.

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The Examiner relies on the following prior art references as evidence
of unpatentability:
Chen 6,436,828 B1 Aug. 20, 2002
Sommer 6,561,871 B1 May 13, 2003
Williams 6,594,542 B1 Jul. 15, 2003
Kajiwara 6,623,343 B2 Sep. 23, 2003 (May 12, 2000)

The rejections as presented by the Examiner are as follows:
1. Claims 1 and 6-15 are rejected under 35 U.S.C. § 102(e) as being
unpatentable over Kajiwara.
2. Claims 3-5 are rejected under 35 U.S.C. § 103(a) as being
unpatentable over Kajiwara in view of Chen.
3. Claims 16-31 are rejected under 35 U.S.C. § 103(a) as being
unpatentable over Sommer or Chen in view of Williams.

With regard to each of the rejections, Appellant argues the respective
claims under the particular rejection as a group. Pursuant to 37 C.F.R. §
41.37(c)(1)(vii), we decide this appeal based upon our selection of the
following claims from each respective claim grouping: (1) with regard to
the § 102(e) rejection above, we address Appellant’s arguments with regard
to claim 1, (2) with regard to the second rejection above, we address
Appellant’s arguments with regard to claim 3, and with regard to the third
rejection above, we address Appellant’s arguments with regard to claims 16.
With regard to claims 17-20 and 25, Appellant’s arguments simply point out
what these claims recite and indicate that Chen, Sommer, and Williams do
not teach or suggest the particular claim limitations. Appellant has not
substantively argued or provided evidence that the features of claims 17-20
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and 25 are not taught or suggested by the combined teachings of the applied
prior art. Pursuant to 37 CFR 41.37(c)(1)(vii), a statement that merely points
out what a claim recites will not be considered an argument for separate
patentability of the claim. Accordingly, claims 17-20 and 25 stand or fall
with claim 16.
OPINION

35 U.S.C. § 102(e) REJECTION OVER KAJIWARA
Appellant argues that Kajiwara’s bladders 255 are independently
inflatable and pressurizable, not independently movable as required by claim
1 (Br. 6). Appellant argues that Kajiwara inflates the bladders 255 to apply
pressure to membrane 250 such that the bladders 255 do not individually
apply pressure to a surface of a semiconductor device (Br. 6). Appellant
contends that Kajiwara’s membrane 250 would spread out the pressure
applied thereto by any one bladder 255 to even out the pressure applied to
the substrate (Br. 6).
We have considered Appellant’s arguments and are unpersuaded for
the reasons below.
A claim is anticipated only if each and every element as set forth in
the claim is found either expressly or inherently described in a single prior
art reference. Verdegaal Bros., Inc. v. Union Oil Co. of Cal., 814 F.2d 628,
631 (Fed. Cir. 1987).
In the present appeal the central issue is whether Kajiwara’s
independently inflatable and pressurizable bladders 255 of the Figure 9
embodiment or membranes 336A-336D of the Figure 24 embodiment
constitutes “independently movable pressurization structures” as claimed.
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We agree with the Examiner that the bladders 255 of the Figure 9
embodiment constitute independently movable pressurization structures.
Similarly, we determine that membranes 336A-336D in the Figure 24
embodiment further constitute independently movable pressurization
structures.
We begin our analysis by construing “independently movable
pressurization structures.” During examination, claim terms are given their
broadest reasonable interpretation consistent with the Specification. In re
Am. Acad. of Sci. Tech. Ctr., 367 F.3d 1359, 1364 (Fed. Cir. 2004).
Appellant’s Specification describes the claimed “independently
moveable pressurization structures” as preferably annular rings 12 whose
movement against the semiconductor device structure 20 are controlled via
actuators 14 (Spec. ¶ [0034], Figures 1 and 2). Appellant discloses that the
actuators 14 may be magnetic controllers or expandable pistons that move
the annular rings according to the expansion of the pistons’ chamber caused
by the application of pressure via a fluid to the chamber (Spec. ¶ [0051],
Figure 8). In other words, Appellant’s “independently movable
pressurization structures” include outer portions of enclosed chambers (i.e.,
the pressurization structures 112” attached to the piston 117) forced
outwardly by a pressurized fluid.
In light of these disclosures, we construe “independently movable
pressurization structures” as including outer portions of enclosed chambers
that independently move outwardly by pressurization of the chambers.
Therefore, contrary to Appellant’s argument, we agree with the
Examiner’s determination that Kajiwara’s bladders 255 of the Figure 9
embodiment for example, constitute independent pressurization structures.
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We also determine that Kajiwara’s membranes 336A to 336D of the Figure
24 embodiment constitute “independently movable pressurization
structures.” Specifically, the outer portions of the bladders 255 or
membranes 336A to 336D constitute the pressurization structure which is
forced outwardly and against the wafer when the bladders 255 or membranes
336A to 336D are pressurized. The pressurization of the bladders 255 or
membranes 336A to 336D causes the membranes or bladders to expand or
inflate, thereby pressing (i.e., biasing) the outer portion of the membranes or
bladders against the wafer. Kajiwara further discloses that the bladders 255
permit a region to be polished or planarized at a higher or lower pressure
than the surrounding areas (i.e., the bladders may independently apply
higher or lower force to regions of the substrate needing it) (Kajiwara, col.
18, ll. 52-67) and that membranes 336A to 336D may be independently
controlled (i.e., pressurized) (Kajiwara, col. 29, ll. 26-30).
For three reasons we are unpersuaded by Appellant’s argument that
Kajiwara’s membrane, for example, would cause any force applied by the
bladders 255 to be dispersed or spread out by the membrane 250. First,
Appellant’s position is contrary to the express teachings of Kajiwara.
Kajiwara expressly discloses that the pressurized gas or fluid in the various
bladders are chosen to provide the desired polishing pressure profile across
the wafer surface and that the bladders may provide higher or lower pressure
to a region of the substrate than to the surrounding regions (Kajiwara, col.
18, ll. 52-56, 62-64). In other words, the force is different at various areas
along the wafer surface such that a desired polishing profile is achieved.
Second, Appellant provides no objective evidence to support the position
that the force applied would be spread out such that the pressure would
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“even out” (Br. 6). Third, the claim does not recite that the pressurization
structures “individually apply pressure to a surface of the semiconductor
device structure” as argued. Instead, the claim recites biasing the
“independently movable pressurization structures to selectively apply a
plurality of different amounts of pressure to different, selected locations of a
backside of the semiconductor device structure” (claim 1). Appellant’s
argument is narrower than the claim.
For the above reasons, we sustain the Examiner’s § 102(e) rejection
of claims 1, and 6-15 over Kajiwara.

35 U.S.C. § 103 REJECTION OVER KAJIWARA IN VIEW OF CHEN
Appellant argues that neither Kajiwara nor Chen discloses biasing
independently movable pressurization structures against the backside of a
semiconductor device (Br.10-11). Appellant further argues that since neither
Kajiwara nor Chen teaches or suggests an apparatus that includes elements
that individually apply pressure to corresponding regions of a semiconductor
substrate, one of ordinary skill in the art would not have been motivated to
combine the teachings of these references in the asserted manner, or had any
reason to expect that their combination in the asserted manner would have
been successful (Br. 11).
Contrary to Appellant’s arguments and as noted above in our
discussion of the § 102(e) rejection over Kajiwara, we find that Kajiwara
discloses biasing independently movable pressurization structures as
claimed. Accordingly, Appellant’s argument is not persuasive.
Moreover, we note that Chen discloses independently and selectively
controlling the force applied by portions of the membrane 104 to the
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substrate 10 by using coils 108, 110, and 112 (Chen, col. 4, ll. 45-60; col. 5,
ll. 5-13, 30-46; col. 6, ll. 23-31). Chen discloses embedding magnetic
particles in the membrane 104 to permit magnetic control of the membrane
(Chen, col. 4, ll. 45-50). Chen further discloses that the coils may be
controlled to amplify or decrease the force in certain areas of the membrane
104 (Chen, col. 6, ll. 1-22).
Based on Chen’s disclosures, we find that Chen, like Kajiwara’s
Figure 24 embodiment, discloses biasing independently movable
pressurization structures (i.e., portions of the membrane 104). Accordingly,
Kajiwara and Chen both disclose the argued claim feature.
We are unpersuaded by Appellant’s motivation and reasonable
expectation of success arguments. Rather, we find that Kajiwara’s Figure 24
embodiment discloses that polishing head 300 may have a single membrane
with four interior walls dividing the internal chamber of the membrane to
form five zones (Kajiwara, col. 29, ll. 24-26). Kajiwara discloses that the
five zones may be controlled either simultaneously or substantially
independently (Kajiwara, col. 29, ll. 26-28).
Chen discloses carrier head 100 having a pressurized chamber 120
with a single membrane 104 (Chen, col. 4, ll. 65-67; col. 5, ll. 1-4). Chen
discloses the membrane 104 having magnetic particles such that the force
applied by the membrane to the substrate 10 may be selectively and
independently controlled using coils 108, 110, and 112 (Chen, col. 4, ll. 45-
50; col. 5, ll. 30-46). Chen further discloses that using the magnetic coils to
control the force applied dispenses with the need for complex pneumatics
and permits non-uniform pressures to be applied to the substrate to
compensate for non-uniform polishing rates (Chen, col. 3, ll. 1-4).
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We find that Chen’s and Kajiwara’s inventions may have a single
membrane forming a pressurized chamber. However, Chen’s invention with
the magnetic particles embedded in the membrane and the coils
advantageously permits control of the force applied without the need for
complex pneumatics and permits non-uniform pressures to be applied to the
substrate to compensate for non-uniform polishing rates. Based on these
findings, we agree with the Examiner that it would have been prima facie
obvious to combine Chen’s method of using magnetic particles and coils
with Kajiwara’s method of controlling the force applied to the substrate in
order to achieve Chen’s advantages noted above.
Accordingly, the prior art itself provides motivation for the
combination. Moreover, Appellant has not rebutted the Examiner’s
motivation of providing better control to Kajiwara’s chemical mechanical
polishing device by using Chen’s method using a magnetically controlled
membrane. Appellant’s motivation argument is without persuasive merit.
Similarly, Appellant’s argument that there is no reasonable
expectation of success is without persuasive merit because both Chen’s and
Kajiwara’s device are structurally similar as noted above. Specifically,
Chen and Kajiwara may have a single membrane forming a pressurized
chamber. Accordingly, based on the structural similarity, one of ordinary
skill would have had a reasonable expectation that combining Chen’s
magnetic particles with Kajiwara’s single membrane in the Figure 24
embodiment and Chen’s coils with Kajiwara’s polishing head 300 would
have successfully produced a chemical mechanical polishing apparatus for
practicing the claimed method. In fact, Chen’s disclosure that using the
coils and magnetic particle embedded membrane successfully allows control
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of the force applied to the substrate supports our determination that there is a
reasonable expectation that Chen’s magnetic control system would be
successfully combined with Kajiwara’s chemical mechanical polishing head
to provide such magnetic control.
For the above reasons, we sustain the Examiner’s § 103 rejection of
claims 3-5 over Kajiwara in view of Chen.

35 U.S.C. § 103 OVER SOMMER OR CHEN IN VIEW OF WILLIAMS
Appellant argues that Sommer, Chen, or Williams do not teach or
suggest “selectively applying [pressure] at locations beneath areas of . . . at
least one second semiconductor device structure that correspond to . . .
raised areas of [a] first semiconductor device structure . . .” as recited in
claim 16 (Br. 12). Appellant contends that since none of the references
disclose controlling the polishing of a second semiconductor device based
on the polishing results from a first semiconductor device, the Examiner’s
combination of references is based on hindsight and there is no reasonable
expectation of success in making the combination (Br. 12-13).
We have considered Appellant’s arguments and are unpersuaded for
the reasons below.
Williams discloses a method of controlling material removal rates
during polishing and for controlling thickness removal during chemical
mechanical polishing using detection, statistical estimation, and time series
analysis (Williams, col. 1, ll. 15-20). Williams discloses that chemical
mechanical polishing issues of semiconductor wafers include global
planarity which are dominated by macro effects, such as polishing pad
velocity or wafer head chucking device (Williams, col. 2, ll. 34-37).
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Williams discloses that uniformity from wafer center to wafer edge is the
usual metric for chemical mechanical polishing processes (Williams, col. 2,
ll. 37-38). Williams discloses that chemical mechanical polishing tools must
provide thickness measurements that can accommodate custom spaced
measurements of chosen length and point density in diameter or radius scan
format (i.e., thickness measurements are taken on different areas of the
wafer) (Williams, col. 2, ll. 40-43). Williams teaches an iterative method for
adjusting the polishing time (Williams, col. 4, ll. 48-61). Williams’ method
polishes a first substrate to determine the actual thickness removal rate and
then adjusts the polishing time for the second substrate based on the
parameters determined from polishing the first substrate (Williams, col. 4, ll.
48-61). The process continues for the remaining “n” substrates (Williams,
col. 4, ll. 62-67; col. 5, ll. 1-12).
Chen discloses a method for controlling the force applied to substrates
during chemical mechanical polishing to control the uniformity of the
polishing (i.e., increasing the force to address a center fast effect and a
center slow effect) (Chen, col. 2, ll. 47-52; col. 3, ll. 1-6; col. 4, ll. 45-60;
col. 5, ll. 5-13; col. 6, ll. 23-31).
Sommer discloses a method for linearly driving a substrate carrier to
polish a substrate surface (Sommer, col. 1, ll. 12-13). Sommer discloses that
a problem with the prior art polishing methods and machines is that they fail
to produce a constant velocity distribution and thereby fail to achieve
uniform material removal over the entire surface which is essential for a
planar result (Sommer, col. 2, ll. 3-9). Sommer discloses that the linear
drive mechanism permits any desired polishing pattern on the substrate to be
achieved (Sommer, col. 13, ll. 32-37). Sommer further discloses that
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magnets in the carrier may be adjusted to accurately control the amount of
force, and thus the polishing rate, the carrier applies to the substrate being
polished (Sommer, col. 13, ll. 24-49).
From the above disclosures, we find, like the Examiner did, that
Williams discloses an iterative process in which the polishing characteristics
of a second substrate are determined based on the results from polishing a
first substrate. Accordingly, contrary to Appellant’s argument, Williams
discloses the argued claim feature.
Appellant’s motivation and reasonable expectation of success
arguments are without persuasive merit. Chen’s, Sommer’s, and Williams’
above disclosures indicate that they are all concerned with controlling the
amount of force applied to the substrate being polished to achieve a more
uniform polished surface. Accordingly, in light of the prior art disclosures,
we conclude that Chen’s, Sommer’s and Williams’ disclosures would have
suggested combining Williams’ iterative process for determining polishing
rates with Chen’s or Sommer’s process of polishing to control the amount of
force applied to a substrate during polishing in order produce a more
uniformly polished substrate. We determine that the teachings of the
references suggest the combination. Thus, the rejection is not based on
impermissible hindsight reasoning.
Furthermore, Appellant’s reasonable expectation of success argument
is premised on none of the applied prior art teaching the argued claim
distinction (Br. 13). However, as noted above, we find that Williams
teaches an iterative process where pre-polish and post-polish thickness
measurements of a first polished substrate are determined and used to adjust
polishing times for the subsequently processed substrate. Chen, Sommer
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and Williams are all directed to polishing methods for achieving a more
uniform substrate profile. Accordingly, we determine that one of ordinary
skill in the art would have had a reasonable expectation that using Williams’
iterative process in Chen’s or Sommer’s method of polishing would
successfully produce a more uniformly polished substrate.
For the above reasons, we sustain the Examiner’s § 103 rejection of
claims 16-31 over Chen or Sommer in view of Williams.

DECISION
The Examiner’s decision 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)(1)(iv).

AFFIRMED

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