Ex Parte Bajaj

Board of Patent Appeals and Interferences

Nov 24, 2009

11369876 (B.P.A.I. Nov. 24, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________________

Ex parte RAJEEV BAJAJ
____________________

Appeal 2009-004787
Application 11/369,876
Technology Center 3700
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Decided: November 24, 2009
____________________

Before LINDA E. HORNER, JOHN C. KERINS and
STEVEN D.A. McCARTHY, Administrative Patent Judges.

McCARTHY, Administrative Patent Judge.

DECISION ON APPEAL

The Appellant’s claims being twice rejected, the Appellant appeals 1
under 35 U.S.C. § 134 from the Examiner’s decision rejecting claims 1-4 2
and 6-8 under 35 U.S.C. § 103(a) as being unpatentable over Park (US 3
6,794,605 B2, issued Sep. 21, 2004) and Yoshida (US 2004/0110381 A1, 4
publ. Jun. 10, 2004); and rejecting claim 5 under § 103(a) as being5
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unpatentable over Park, Yoshida and Choo (US 2003/0209528 A1, publ. 1
Nov. 13, 2003). We have jurisdiction under 35 U.S.C. § 6(b). An oral 2
hearing was held on November 4, 2009. 3
We REVERSE. Pursuant to 37 C.F.R. § 41.50(b), we enter NEW 4
GROUNDS OF REJECTION against claims 1 and 3. 5
6
OPINION 7
The claims on appeal relate to a pad conditioning apparatus and 8
method. The pads to be conditioned by the apparatus and method are 9
intended for use in the chemical mechanical planarization [“CMP”] of 10
wafers for semiconductor devices. (Spec. 2, para. 0002.) 11
Yoshida describes CMP as a technique for planarizing a wafer 12
surface. (Yoshida 1, para. 0003.) When a wafer is planarized in a CMP 13
process, the CMP apparatus supplies a polishing slurry onto the surface of a 14
polishing pad and rotates both the wafer and the polishing pad while 15
pressing the wafer and the polishing pad against each other. (Yoshida 1, 16
para. 0016.) Either before the wafer is planarized or simultaneously with the 17
planarization process, the polishing pad is conditioned or dressed to restore 18
its surface roughness. Yoshida describes known dressers as disk-like 19
structures having small diamond particles fixed to their flat, exposed 20
surfaces. The polishing pad is conditioned by rotating the dresser as the 21
polishing pad is pressed against the flat, exposed surface of the dresser. 22
(Yoshida 1, para. 0017.) 23
Claims 1 and 8 are independent. Claim 1 recites: 24
1. A pad conditioning apparatus comprising a 25
laser source configured to provide at least one laser 26
beam incident on a polishing pad undergoing 27
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conditioning while polishing a wafer and mounted 1
so as to be capable of traversing a surface of the 2
polishing pad during said polishing of the wafer. 3
The Examiner finds that Park discloses an apparatus for forming 4
grooves on a polishing pad 10 for enhancing slurry distribution by using a 5
laser 100 for forming the grooves while the pad rotates and is translated 6
along three axes so as to effect full pad coverage with the grooves. (Ans. 3, 7
citing Park, col. 6, l. 40.) The Examiner also finds that Park discloses 8
conditioning a pad with a grooving conditioner 50 while polishing a wafer 9
30. (Ans. 4, citing Park, fig. 1.) The Examiner finds that Yoshida teaches 10
conditioning a pad simultaneously with the polishing of a wafer. (Ans. 4, 11
citing Yoshida, para. 0017.) The Examiner concludes that it would have 12
been obvious “to condition the pad of Park while simultaneously polishing a 13
wafer, as shown by Figure 1 of Park and taught by Yoshida, in order to 14
efficiently process a batch of wafers without machine down-time.” (Ans. 4.) 15
As correctly pointed out by the Appellant’s declarants, Park describes 16
a method for fabricating a CMP pad. (See Declaration of Rajiv K. Singh, 17
Ph.D. [“Singh Declaration”], para. 8;1 see also Park, col. 4, ll. 20-35.) Claim 18
1 recites “[a] pad conditioning apparatus comprising a laser source 19
configured to provide at least one laser beam incident on a polishing pad 20
undergoing conditioning while polishing a wafer . . . .” Claim 8 recites a 21
method including the step of “directing a laser beam from [a] polishing pad 22

1 Paragraphs 4-11 of the Declaration of David A. Dornfeld, Ph.D
appear to be similar in content to the corresponding paragraphs of the Singh
Declaration. For purposes of brevity, only the Singh Declaration will be
cited in the remainder of the opinion. Any findings or conclusions regarding
the materiality, credibility or probative value of statements in the Singh
Declaration apply equally to the corresponding statements of Dr. Dornfeld.
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conditioning head onto the surface of the polishing pad . . . while a wafer is 1
being pressed against the polishing pad.” [Emphasis added]. The 2
dispositive issue in this appeal is: 3
Has the Appellant shown that the Examiner failed to 4
articulate reasoning with some rational underpinning sufficient 5
to support the conclusion that one of ordinary skill in the art 6
would have had reason to direct a laser beam onto the surface of 7
a polishing pad while polishing a wafer? 8
The Examiner articulates no apparent reason why one of ordinary skill 9
in the art would have improved conventional pad conditioning apparatuses 10
or processes by directing a laser beam rather than a conventional dresser 11
onto the surface of the polishing pad while polishing a wafer. Had one of 12
ordinary skill in the art reason to use a laser not only to fabricate but also to 13
condition a pad, the efficiencies suggested by Figure 2 of Park and 14
paragraph 0017 of Yoshida (see, e.g., Ans. 5) might have provided reason to 15
apply the laser to the pad while polishing the wafer. The efficiencies cited 16
by the Examiner do not explain why one of ordinary skill in the art would 17
have had an apparent reason to apply a laser beam to any pad conditioning 18
process, however. 19
The Appellant presents two reasons why one of ordinary skill in the 20
art would have been disinclined to use a laser to condition a polishing pad 21
while polishing a wafer. First, the Appellant asserts that pad conditioning or 22
dressing processes remove the top layer of pad material distorted during 23
polishing whereas Park discloses the cutting of slurry distribution grooves in 24
the pad. Second, the Appellant asserts that the polishing pad inherently 25
would have been wet while polishing a wafer due to the polishing slurry or 26
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solution used in the CMP process.2 In the absence of an apparent reason 1
why one of ordinary skill in the art would have applied a laser beam to a 2
conditioning process, these asserted differences between Park’s application 3
of a laser in fabricating a polishing pad and the application of a laser to pad 4
conditioning are persuasive of nonobviousness. 5
The Appellant has shown that the Examiner failed to articulate 6
reasoning with some rational underpinning sufficient to support the 7
conclusion that one of ordinary skill in the art would have had reason to 8
direct a laser beam onto the surface of a polishing pad while polishing a 9
wafer. Therefore, the Appellant has shown that the Examiner erred in 10
rejecting claims 1-4 and 6-8 under § 103(a) as being unpatentable over Park 11
and Yoshida. 12
The Examiner cites Choo in the rejection of claim 5 as suggestive of 13
the use of CO2 and diode lasers having power in the range of 50-250 W to 14
make cuts in a workpiece. (Ans. 4.) Choo discloses the use of CO2 and 15
diode lasers to cut glass sheets for liquid crystal display panels. (Choo 4, 16
paras. 0088 and 0095.) The Examiner does not rely on Choo to make up the 17
deficiencies in the teachings Park and Yoshida. Therefore, the Appellant’s 18
showing of error in the rejection of claim 1 is sufficient also to show that the 19

2 The Examiner disputes the latter assertion but provides no evidence or
technical reasoning sufficient to show a sound basis for belief that the
environment in which a pad conditioning process carried out while polishing
a wafer would not have to be wet. Since the wet environment is both
inherent in the claimed subject matter and disclosed in the Specification
(Spec. 6, para. 0021), it is part of the claimed subject matter as a whole
which must be considered in reaching a conclusion as to obviousness. See
In re Antonie, 559 F.2d 618, 619 (CCPA 1977).
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Examiner erred in rejecting claim 5 under § 103(a) as being unpatentable 1
over Park, Yoshida and Choo. 2
3
NEW GROUND OF REJECTION 4
Pursuant to 37 C.F.R. § 41.50(b), we enter new grounds of rejection 5
against claims 1 and 3 under 35 U.S.C. § 102(a) as being anticipated by 6
Yoshida or, in the alternative, under § 103(a) as being unpatentable over 7
Yoshida. 8
With respect to claim 1, Figure 6 of Yoshida schematically discloses a 9
pad conditioning apparatus comprising a laser source configured to provide 10
at least one laser beam incident on a polishing pad undergoing conditioning. 11
More specifically, Yoshida discloses several embodiments of a CMP 12
apparatus. (Yoshida 6, para. 0088.) Yoshida’s second embodiment includes 13
a polishing table 11; a polishing pad 12 attached to the top polishing surface 14
of the polishing table 11; a substrate carrier 14 for holding a substrate to be 15
polished; and a dresser 16. (Yoshida 6, para. 0089.) 16
A variant of the second embodiment includes a laser transmitter/ 17
receiver 29 provided at the center of the dresser 16. The laser transmitter/ 18
receiver 29 includes a laser irradiation source and a laser power detector. 19
(Id.) In this variant, laser light from the laser irradiation source irradiates the 20
polishing pad 12 while the pad is being dressed. (Yoshida 7, para. 0102.) 21
The laser power detector detects the laser light reflected by the polishing pad 22
12. (Id.) When the intensity of the laser light detected by the laser power 23
detector deviates from a previously set adequate range so as to indicate a 24
deviation from the proper degree of pad surface roughness, a controller gives 25
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an alarm and changes the pressure of the dresser 16 on the pad 12 so as to 1
perform an adequate dressing of the pad 12. (Yoshida 7, para. 0104.) 2
Yoshida discloses that “[t]he surface roughness of a polishing pad is 3
monitored in carrying out dressing before or simultaneously with polishing.” 4
(Yoshida 6, para. 0088.) Yoshida does not describe the polishing table, 5
polishing pad or substrate of the variant of the second embodiment 6
separately from the description of the second embodiment itself. Neither 7
does Yoshida describe the timing of the wafer polishing and pad 8
conditioning steps separately from the description provided of the second 9
embodiment. (See Yoshida, paras. 0099-105.) These facts imply that the 10
variant of the second embodiment, like the second embodiment itself, carries 11
out dressing simultaneously with polishing. Since the laser irradiation 12
source irradiates the pad during dressing and dressing is carried out 13
simultaneously with polishing, the laser irradiation source is configured to 14
provide at least one laser beam incident on a polishing pad undergoing 15
conditioning while polishing a wafer. 16
Even were it assumed that Yoshida’s failure to describe the variant of 17
the second embodiment as capable of carrying out dressing before or 18
simultaneously with polishing implies that the variant does not carry out 19
wafer polishing and pad conditioning simultaneously, Yoshida’s second 20
embodiment and the variant of the second embodiment are similar devices. 21
The variant differs from the second embodiment only in that the variant uses 22
a laser transmitter/detector 29 to monitor the surface roughness of the pad 12 23
during conditioning while the second embodiment itself uses a torque 24
monitor 18 to perform substantially the same function. (Compare Yoshida 25
6-7, paras. 0091-96 with id. 7, paras. 0102-04.) 26
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Since Yoshida discloses that the second embodiment carries out wafer 1
polishing and pad conditioning simultaneously (see Yoshida 6, para. 0088) 2
and Yoshida teaches that carrying out the two steps simultaneously produces 3
the efficiencies pointed out by the Examiner in the Answer (see Ans. 4 and 4
5; see also Yoshida 1, para. 0017 and 6, para. 0084), it would have been 5
obvious to improve the variant of the second embodiment by the same 6
technique applied to the second embodiment itself, namely, by conditioning 7
the polishing pad simultaneously with the polishing of wafers. See KSR Int’l 8
Co. v. Teleflex, Inc., 550 U.S. 398, 417 (2007) (“[I]f a technique has been 9
used to improve one device, and a person of ordinary skill in the art would 10
recognize that it would improve similar devices in the same way, using the 11
technology is obvious unless its actual application is beyond his or her 12
skill.”). Given the high degree of similarity between the variant and the 13
second embodiment itself, the results of the improvement would have been 14
predictable by one of ordinary skill in the art. 15
If Yoshida’s variant of the second embodiment is operated so as to 16
simultaneously polish wafers and condition the pad, the laser irradiation 17
source necessarily will be mounted so as to be capable of traversing the 18
surface of the polishing pad during the polishing of a wafer. The ordinary 19
usage of “traverse” is sufficiently broad to include “to go or travel across or 20
over.” WEBSTER’S THIRD NEW INT’L DICTIONARY 2433 (G&C Merriam Co. 21
1971)(“traverse,” entry 2, def. 3a). During simultaneous wafer polishing 22
and pad conditioning, the pad 12, mounted on the polishing table 11, rotates. 23
(See Yoshida 6, para. 0090.) The dresser 16 appears to remain fixed relative 24
to the axis of rotation of the polishing table 11. Hence, the laser irradiation 25
source, positioned at the center of the dresser 16, traverses the surface of the 26
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polishing pad 12 during the polishing of a wafer in the sense that the dresser 1
16 travels relative to the pad across or over an annular path on the surface of 2
the pad. 3
Therefore, Yoshida discloses each element of claim 1. Even if it did 4
not, however, one of ordinary skill in the art would have had an apparent 5
reason to improve Yoshida in such a manner as to meet each limitation of 6
claim 1. 7
Claim 1 does not recite that the laser beam conditions the pad. 8
Although the laser irradiation source disclosed by Yoshida does not 9
condition the pad, Yoshida’s variant of the second embodiment meets all of 10
the limitations of claim 1. Since Yoshida’s laser irradiation source irradiates 11
the pad as the pad is undergoing conditioning while polishing a wafer, or 12
alternatively, it would have been obvious to modify Yoshida’s variant of the 13
second embodiment so that the laser irradiation source irradiated the pad as 14
the pad was undergoing conditioning while polishing a wafer, the 15
Appellant’s opinion evidence concerning the differences between the use of 16
a laser in a dry manufacturing environment as opposed to a wet conditioning 17
environment are not entitled to persuasive weight in determining whether the 18
subject matter of claim 1 is anticipated or, in the alternative, obvious. 19
Figure 6 of Yoshida appears to show the laser irradiation source 20
mounted such that the laser light from the laser irradiation source is incident 21
perpendicular to the plane, that is, the surface, of the polishing pad 12. 22
Therefore, Yoshida discloses each element of claim 3. Even if it did not, 23
however, the reasoning supporting the new ground of rejection against claim 24
1 implies that one of ordinary skill in the art would have had an apparent 25
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reason to improve Yoshida in such a manner as to meet each limitation of 1
claim 3. 2
The opinion, expressed in the Singh Declaration, that the laser 3
conditioning apparatus of claims 1 and 3 “solve[s] several problems that 4
have been long felt in the industry” is entitled to no weight in determining 5
whether Yoshida anticipates claims 1 and 3 and little weight in determining 6
whether claims 1 and 3 are unpatentable over Yoshida. Dr. Singh identifies 7
neither how long the alleged problems were felt, who else besides the 8
Appellant sought to solve the alleged problems, and what steps those others 9
might have taken in an attempt to solve the problems. Without such details, 10
the probative value of a reference disclosing an embodiment as close to the 11
claimed subject matter as Yoshida’s variant of the second embodiment is to 12
the subject matter of claims 1 and 3 significantly outweighs the probative 13
value of the unsupported opinion regarding long felt need, in concluding that 14
the subject matter of claims 1 and 3 would have been, if not anticipated, 15
obvious. See Ex Parte Jellá, 90 U.S.P.Q.2d 1009, 1019 (BPAI 2008). 16
17
DECISION 18
We REVERSE the Examiner’s decision rejecting claims 1-8. 19
Pursuant to 37 C.F.R. § 41.50(b), we enter NEW GROUNDS OF 20
REJECTION against claims 1 and 3 under 35 U.S.C. § 102(a) as being 21
anticipated by Yoshida or, in the alternative, under § 103(a) as being 22
unpatentable over Yoshida. 23
Under 37 C.F.R. § 41.50(b) a new ground of rejection has been 24
entered. 37 C.F.R. § 41.50(b) provides that, “[a] new ground of rejection 25
pursuant to this paragraph shall not be considered final for judicial review.” 26
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Regarding the new ground of rejection, Appellant must, WITHIN 1
TWO MONTHS FROM THE DATE OF THE DECISION, exercise one of the 2
following options with respect to the new ground of rejection, in order to 3
avoid termination of the appeal as to the rejected claims: 4
(1) Reopen prosecution. Submit an appropriate 5
amendment of the claims so rejected or new 6
evidence relating to the claims so rejected, or both, 7
and have the matter reconsidered by the examiner, 8
in which event the proceeding will be remanded to 9
the examiner. . . . 10
11
(2) Request rehearing. Request that the 12
proceeding be reheard under § 41.52 by the Board 13
upon the same record. . . . 14
15
No time period for taking any subsequent action in connection with 16
this appeal may be extended under 37 C.F.R. § 1.136(a) (2007). 17
18
REVERSED; 37 C.F.R. § 41.50(b) 19
20
21
Klh 22
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