Ex Parte Hoogkamp et al

Board of Patent Appeals and Interferences

Jun 30, 2009

10847656 (B.P.A.I. Jun. 30, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte JAN FREDERIK HOOGKAMP,
ALBERT JAN HENDRIK KLOMP, and
JOHANNES HENDRIKUS GERTRUDIS FRANSSEN
____________

Appeal 2009-002361
Application 10/847,656
Technology Center 1700
____________

Decided1: June 30, 2009
____________

Before PETER F. KRATZ, JEFFREY T. SMITH, and
LINDA M. GAUDETTE, Administrative Patent Judges.

KRATZ, 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 2009-002361
Application 10/847,656

This is a decision on an appeal under 35 U.S.C. § 134 from the
Examiner’s final rejection of claims 1, 3, 4, 6-8, 10, and 12-15. We have
jurisdiction pursuant to 35 U.S.C. § 6.
Appellants’ claimed invention is directed to a lithographic projection
apparatus and a lithographic patterning method including, inter alia, a load
lock used for transferring an object between a patterning chamber having a
first pressure and a second environment disposed at a second pressure.
Claims 1, 8, and 15 are illustrative and reproduced below:
1. A lithographic projection apparatus comprising:

a radiation system to provide a beam of radiation;

a lithography patterning chamber comprising

a support constructed to support a patterning device, the
patterning device serving to pattern the beam of radiation according to
a desired pattern;

a substrate table for holding a substrate; and

a projection system for projecting the patterned beam onto a
target portion of the substrate; and

a load lock for transferring an object from the lithography patterning
chamber having a first pressure to a second environment having a second
pressure, the first pressure being lower than the second pressure, or for
transferring the object from the second environment to the lithography
patterning chamber, the load lock defining a chamber and comprising a first
door facing the lithography patterning chamber, and a second door facing
the second environment, and the load lock further comprising a gas inlet for
venting the load lock; and

a gas supply that supplies, at least during part of the transfer of the
object, a gas to the gas inlet, the gas being essentially free from at least one
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of particles, oxygen, hydrocarbon, or H20, to create a pressure in the load
lock that is higher than the second pressure so that when the second door is
open, the gas flows out of the load lock and into the second environment to
reduce migration of particles from the second environment into the load
lock.

8. A device manufacturing method comprising:

providing a substrate that is at least partially covered by a layer of
radiation-sensitive material in a lithographic patterning chamber;

projecting a patterned beam of radiation onto a target portion of the
layer of radiation-sensitive material disposed on the substrate;

transferring an object between a second environment and said
lithography patterning chamber via a load lock, the load lock defining a
chamber and comprising a first door facing the lithography patterning
chamber and a second door facing the second environment, the second
environment having a pressure that is higher than pressure within the
lithography patterning chamber; and

venting the load lock with a gas that is essentially free from at least
one of particles, oxygen, hydrocarbon, or H20 to a pressure that is higher
than the pressure of the second environment during at least part of the
transfer so that when the second door is open, the gas flows out of the load
lock and into the second environment to reduce migration of particles from
the second environment into the load lock.

15. A device manufacturing method comprising:

providing a substrate that is at least partially covered by a layer of
radiation-sensitive material in a lithography patterning chamber;

providing a beam of radiation using a radiation system;

patterning the beam of radiation with a patterning device;

projecting the patterned beam of radiation onto a target portion of the
layer of radiation-sensitive material; and
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Application 10/847,656

transferring an object from and to said lithography patterning chamber
via a load lock, the load lock defining a chamber and comprising a first door
facing the lithography patterning chamber and a second door facing a second
environment, the second environment having a pressure that is higher than
pressure within the lithography patterning chamber, the object being one of
said substrate and said patterning device; and

venting the load lock with a gas that is essentially free from at least
one from the group consisting of particles, oxygen, hydrocarbon, or H20 to a
pressure that is higher than the pressure of the second environment during at
least part of the transfer so that when the second door is open, the gas flows
out of the load lock and into the second environment to reduce migration of
particles from the second environment into the load lock.

The Examiner relies on the following prior art references as evidence
in rejecting the appealed claims:
Kawamura 5,981,399 Nov. 09, 1999
Hara 2001/0035942 A1 Nov. 01, 2001
Fairbairn 6,486,444 B1 Nov. 26, 2002

The Examiner maintains the following ground of rejection:
Claims 1, 3, 4, 6-8, 10, and 12-15 stand rejected under 35 U.S.C. § 103(a) as
being unpatentable over Hara in view of Kawamura, and Fairbairn.
We affirm.
Appellants do not furnish reasonably specific arguments for the
separate patentability of the dependent claims and generally argue
independent method claims 8 and 15 together as a group. Thus, we decide
this appeal on the basis of our selection of claim 1 as the representative
claim for commonly rejected and appealed apparatus claims 1, 3, 4, 6, and 7,
and our selection of claim 15 as the representative claim for commonly
rejected and appealed method claims 8, 10, and 12-15.
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Appellants do not dispute the Examiner’s determination that Hara
discloses or suggests an apparatus and process corresponding to the claimed
subject matter but for argued load lock gas supply operational features
including a load lock operational pressure, and load lock operational gas
outflow features, which features are argued as not being taught or suggested
by the applied references (App. Br. 9-18; Reply Br. 2- 6; Ans. 3 and 4).

ISSUES
Have Appellants identified reversible error in the Examiner’s
determination that the claimed subject matter would have been prima facie
obvious to one of ordinary skill in the art from the combined teachings of
Hara, Kawamura, and Fairbairn based on load lock gas supply and
associated load lock operational features that are argued as being required by
the appealed claims, but not taught or suggested by the applied references?

PRINCIPLES OF LAW
On appeal to this Board, Appellants must show that the Examiner
erred in rejecting the claims. Cf. In re Kahn, 441 F.3d 977, 985-986 (Fed.
Cir. 2006); see also 37 C.F.R. § 41.37(c)(1)(vii).
It is well settled that the United States Patent and Trademark Office
(PTO) is obligated to give claim terms their broadest reasonable
interpretation, taking into account any enlightenment by way of definitions
or otherwise found in the specification. In re ICON Health and Fitness, Inc.,
496 F.3d 1374, 1378-79 (Fed. Cir. 2007).
Section 103 forbids issuance of a patent when “the
differences between the subject matter sought to be patented
and the prior art are such that the subject matter as a whole
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would have been obvious at the time the invention was made
to a person having ordinary skill in the art to which said
subject matter pertains.”

KSR Int’l Co. v. Teleflex, Inc., 550 U.S. 398, 406 (2007) (quoting 35 U.S.C.
§ 103(a)).
KSR disapproved a rigid approach to obviousness (i.e., an analysis
limited to lack of teaching, suggestion, or motivation). KSR, 550 U.S. at 419
(“The obviousness analysis cannot be confined by a formalistic conception
of the words teaching, suggestion, and motivation, or by overemphasis on
the importance of published articles and the explicit content of issued
patents.”). See also DyStar Textilfarben GmbH & Co. Deutschland KG v.
C.H. Patrick Co., 464 F.3d 1356, 1367-68 (Fed. Cir. 2006) (citation omitted)
(“Our suggestion test is in actuality quite flexible and not only permits, but
requires, consideration of common knowledge and common sense”); Alza
Corp. v. Mylan Labs., Inc., 464 F.3d 1286, 1291 (Fed. Cir. 2006) (“There is
flexibility in our obviousness jurisprudence because a motivation may be
found implicitly in the prior art. We do not have a rigid test that requires an
actual teaching to combine . . . .”).
See Okajima v. Bourdeau, 261 F.3d 1350, 1354-55 (Fed. Cir. 2001)
(quoting Litton Indus. Prods., Inc. v. Solid State Sys. Corp., 775 F.2d 158,
163-164 (Fed. Cir. 1985)) (“[T]he absence of specific findings on the level
of skill in the art does not give rise to reversible error ‘where the prior art
itself reflects an appropriate level and [the] need for testimony is not
shown’”).
That is, the question of obviousness cannot be approached on the basis
that an artisan having ordinary skill would have known only what they read
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in the references, because such artisan is presumed to know something about
the art apart from what the references disclose. See In re Jacoby, 309 F.2d
513, 516 (CCPA 1962).
Nor is it necessary that suggestion or motivation be found within the
four corners of the references themselves. Indeed, a conclusion of
obviousness may be made from “‘common knowledge and common sense of
the person of ordinary skill in the art without any specific hint or suggestion
in a particular reference.’” See In re Bozek, 416 F.2d 1385, 1390 (CCPA
1969). After all, it is well settled that “[t]he person of ordinary skill [in the
art] is a hypothetical person who is presumed to be aware of all the pertinent
prior art.” Custom Accessories, Inc. v. Jeffrey-Allan Indus., Inc., 807 F.2d
955, 962-63 (Fed. Cir. 1986).
A claimed apparatus must be distinguished from the prior art
apparatus on the basis of structure. In re Danly, 263 F.2d 844, 848 (CCPA
1959). Therefore, the patentability of an apparatus claim depends only on
the claimed structure, not on the use or purpose of that structure, Catalina
Mktg. Int'l., Inc. v. Coolsavings.com Inc., 289 F.3d 801, 809 (Fed. Cir.
2002), or the function or result of that structure. In re Gardiner, 171 F.2d
313, 315-16 (CCPA 1948). Language in an apparatus claim directed to the
function, operation, intent-of-use, and materials upon which these apparatus
components work that does not structurally limit the apparatus components
or patentably differentiate the claimed apparatus from an otherwise identical
prior art apparatus will not support patentability. See, e.g., In re Rishoi, 197
F.2d 342, 344-45 (CCPA 1952); In re Otto, 312 F.2d 937, 940 (CCPA
1963); In re Ludtke, 441 F.2d 660, 663-64 (CCPA 1971); In re Yanush, 477
F.2d 958, 959 (CCPA 1973).
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FINDINGS OF FACT
Hara teaches or suggests a load lock, such as load lock 36, for
transferring objects between processing chamber 4, 26 and an external
environment (Fig. 1). Hara’s load lock includes, inter alia, a valve (door) 37
facing a second external environment, a valve (door) 38 facing processing
chambers 4, 26, and a gas supply 57. Id.
Hara teaches that gas supply source 57 supplies nitrogen or helium
gas to wafer load lock chamber 36 via a pipe 82 (¶¶ 0102 and 0189).
Hara discloses that gas is supplied to the load lock chamber 36 with
the valves (doors) closed and that the gas supply can stop when a
predetermined state is reached when unloading a wafer via lock chamber 36
(¶ 0192). The gate valve (door) 38 can be opened to transfer the wafer to the
load lock chamber, the valve 38 closed, and then the valve 37 opened for
unloading the wafer (id.).
Also, Hara discloses that gas can be supplied to the lock chamber 36
when the load lock gate valve 36 is open, at least during a wafer loading
transfer (¶ 0190).
Appellants acknowledge the prior art availability of load locks,
wherein a load lock comprises:
a chamber, that comprises at least two doors, where a first door
typically faces vacuum conditions, having a pressure Pvac, and
a second door typically faces atmospheric conditions, having a
pressure Patm. When both doors are closed, the pressure in the
load lock can be adjusted by pumping down or venting the load
lock to a desired pressure level.

Spec. ¶ 0013.
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Moreover, Appellants acknowledge that a load lock typically operates
as follows:
Moving, for instance, a substrate from the atmospheric
environment to the vacuum environment via the load lock,
usually comprises the following steps: opening the second door
facing the atmospheric conditions Patm; delivering the substrate
from atmospheric conditions Patm in the load lock; closing the
second door; pumping down the load lock to vacuum conditions
Pvac; opening the first door facing the vacuum conditions Pvac;
and delivering the substrate from the load lock to the vacuum
conditions Pvac.

The movement of a substrate in the opposite direction,
i.e. from the vacuum conditions to the atmospheric conditions,
usually comprises the following steps: opening the first door
facing the vacuum conditions Pvac; delivering the substrate from
the vacuum conditions Pvac into the load lock; closing the first
door; venting the load lock to atmospheric conditions Patm;
opening the second door facing the atmospheric conditions Patm;
and delivering the substrate from the load lock to the
atmospheric conditions Patm.

Spec. ¶ 0014 and ¶ 0015.
Kawamura discloses that a load lock chamber for transferring
substrates or pieces thereof into and out of a semiconductor fabrication
device can be supplied with inert gas at pressures 50 torr higher than
atmospheric pressure during its operation (col. 5, ll. 1-24). Kawamura
teaches or suggests that preventing the contamination of substrate surfaces
and upholding manufactured device quality requires isolation of the
fabrication process chambers from the outside atmosphere (col. 1, ll. 14-22).
Fairbairn provides a small volume load lock chamber for transferring
substrates into and out of the apparatus for making electronic devices (col. 1,
ll. 10-16, col. 5, ll. 15-28, and col. 8, ll. 3-8). Fairbairn teaches or suggests
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venting the load lock chamber up to atmosphere using a gas diffuser, which
diffuser can be connected to a nitrogen gas purge line, and preventing gas –
bound particles from entering a transfer chamber of the apparatus by
exhausting gases out of the system via the load lock chamber in a continuous
manner (col. 7, l. 53- col. 8, l. 3). Fairbairn discloses that the load lock
chamber is pumped down using a vacuum pump and an exhaust line (col. 7,
ll. 41-52).

ANALYSIS
Representative claim 1 is drawn to an apparatus.
Appellants have not fairly explained how the presented arguments
concerning load lock operation establish a structure required by
representative claim 1 that is not taught or suggested by Hara alone, much
less in combination with Kawamura and Fairbairn (see generally App. Br. &
Reply Brief). In this regard, representative claim 1 is drawn to an apparatus,
not a method. Like representative appealed claim 1, Hara teaches or
suggests the provision of a load lock chamber with first and second doors
(valves) configured for transferring wafers (objects) between a patterning
chamber at a first pressure and an environment at a second pressure together
with an inert gas supply and gas inlet for the load lock, as we noted above.
Appellants have not established that the gas supply of Hara would not
have been capable of or obviously made capable of supplying gas at a
pressure such that the load lock would reasonably be expected to experience
a pressure higher than a second pressure at least during a part of the wafer
transfer time to or from the interior processing chambers such that when the
second door (valve 37) of Hara opens gas outflows therefrom. Moreover,
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and as we found above, Kawamura discloses that inert gas supply pressure to
a lock chamber is known to include supply at a pressure above atmospheric
pressure. Even if the load lock gas supply system of Hara were not
considered capable of supplying gas at a pressure greater than the second
environment pressure (atmospheric pressure), modifying Hara to provide for
such a feature would have been expected to be at least an obvious option, to
one of ordinary skill in the art, so as to cause the inert gas to flow into the
load lock chamber in an expeditious manner and/or to provide for the
possibility of a load lock pressure sufficient to cause gas to flow out of the
load lock upon opening of the valve door 37. This is so because one of
ordinary skill in the art would have readily recognized the benefit of higher
load lock pressures in reducing influx of atmospheric gases into the interior
of the load lock chamber upon opening so as to reduce the likelihood of
unwanted material entering the wafer processing chambers of the apparatus
with the wafers.
In essence, Appellants’ arguments for allegedly distinguishing over
the Examiner’s obviousness rejection of representative claim 1 relate to
functions or use of the claimed apparatus. Appellants have not shown that
the Examiner reversibly erred by persuasively establishing that Hara’s
apparatus, which apparatus substantially corresponds to the claimed
apparatus, would not have been reasonably, or obviously, expected to
possess the capability of performing the recited functions, with or without
the additional teachings of Kawamura and/or Fairbairn. Appellants’ asserted
load lock operating pressure and alleged gas flow distinctions fall short in
establishing a patentable structural distinction. Therefore, we sustain the
obviousness rejection of claims 1, 3, 4, 6, and 7, on this record.
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Concerning representative method claim 15, we note that claim 15
requires venting the load lock to any pressure higher than a second
environment pressure during at least a part of the transfer of an object from
and to a lithography patterning chamber. Representative claim 15 does not
require that the load lock chamber pressure be maintained higher than a
second environment pressure for any particular length of time or particular
period of time so long as the high pressure condition occurs at a time period
that coincides with a time that an object is at some stage of transfer into or
out of the patterning chamber from the second environment. In this regard,
the second environment of representative claim 15 is not limited to
excluding any location or environment so long as reaching that second
environment involves use of the load lock chamber. Also, claim 15 does not
require venting gas to be supplied to the load lock during the time when the
second door is open. However, claim 15 does requires some of the gas
involved in providing the higher pressure condition in the load lock chamber
to be released through the load lock and into the second environment at
some time when the load lock door is open in order to reduce to any extent
migration of particles from the second environment into the load lock.
As acknowledged by the Examiner, Hara does not expressly describe
the method step of supplying the venting gas (nitrogen or helium) to a load
lock chamber (i.e., chamber 36) in a fashion such that the load lock chamber
experiences a pressure condition that is higher than the pressure
(atmospheric) in the second environment located outside the apparatus and
such that some of that higher pressure load lock chamber gas would be
released to the second environment via the periodic opening of a door; for
example, valve 37 (Ans. 3-5). Thus, representative claim 15 differs from the
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express teachings of Hara in requiring the higher pressure loading of the
lock chamber with venting gas, such as the nitrogen of Hara.
As we noted above and as the Examiner correctly determined in the
Answer, Kawamura discloses that a load lock chamber for processing wafers
can be vented with venting gas at a pressure higher than atmospheric
pressure (Ans. 5). Moreover, Kawamura teaches or suggests, as one of
ordinary skill in the art would have understood, that the load lock chambers
should be operated in a manner such that outside environmental
contaminants do not compromise manufactured device quality by making
their way to substrate surfaces in the processing chambers of the device
manufacturing apparatus. Given the above, we agree with the Examiner that
one of ordinary skill in the art would have readily recognized the added
value in venting the load lock chambers of Hara to a pressure that exceeds
the atmospheric outside environmental pressure to some extent such that
when the door, such as valve 37, is opened the initial flow of gas will be
outward toward the environment rather than inward toward the load lock
chambers, and potentially the processing chambers.
As such, Appellants’ arguments suggesting a lack of suggestion for
the claimed higher gas filling (venting) pressure conditions for the load lock
chamber during a portion of the wafer transfer operation are not persuasive
(App. Br. 9-12) of reversible error in the Examiner’s obviousness rejection
of representative claim 15. In this regard, we further note that there is no
requirement for an explicit or inherent disclosure of a higher pressure
condition in the load lock chamber of Kawamura, as Appellants argue, for
one of ordinary skill in the art to derive a suggestion of employing such a
higher pressure fill for a load lock chamber based on the teachings of
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Kawamura with respect to using higher inert feed gas pressures coupled with
the need to keep the external second environment gases out of the processing
chambers, as discussed above (App. Br. 11; Kawamura, col. 5, ll. 1-24 and
col. 1, ll. 14-22).
Of course, the use of a higher load lock chamber filling gas pressure
for wafer transfer in Hara would reasonably be expected by an ordinarily
skilled artisan to result in inert fill gas flow out of the load lock chamber
upon opening the load lock door facing the second environment during
wafer transfer, as discussed above. Accordingly, we need not reach the
additional teachings of Fairbairn in sustaining the Examiner’s obviousness
rejection.
However, we further note that Appellants’ characterization of the load
lock operating disclosure of Fairbairn, in combination with the other applied
references, as suggesting an exacerbation of problems Appellants desire to
obviate appears somewhat off the mark (Reply Br. 5). This is because
Fairbairn’s concern with keeping gas-bound particles from entering the
transfer chamber (and ultimately the process chambers) via the load lock
chamber is substantially the same concern as Appellants identify in the
Specification and related to the substrate contamination concern identified
by Kawamura (Fairbairn, col. 7, ll. 53-55; Spec. ¶ 0019; Kawamura, col. 1,
ll. 14-22). One of ordinary skill in the art would readily recognize that
guarding against ingress of environmental contaminants into interior transfer
and processing chambers operated at differing ambient conditions, including
low pressure, begins at the gateway to the apparatus interior; that is, at the
lock chambers used to supply substrates to and from the lower pressure
processing chambers within. Kawamura’s teaching of using higher than
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atmospheric pressure for the inert gas used in the load lock chamber in
combination with Hara, with or without Fairbairn, would have reasonably
suggested venting the load lock chamber with inert gas to a pressure above
the external second environment pressure (atmospheric) to an ordinarily
skilled artisan cognizant of the potential contamination of substrates due to
any influx of particle contaminated environmental gas from outside the
apparatus through the load lock chamber and into the processing chambers
for reasons discussed above.
As a final point, we note that Appellants have not proffered, much less
established, unexpected results for an apparatus or process commensurate in
scope with the claimed subject matter.
Accordingly, we shall sustain the Examiner’s rejection of all of the
appealed claims.

CONCLUSION
Appellants have not identified reversible error in the Examiner’s
determination that the claimed subject matter would have been prima facie
obvious to one of ordinary skill in the art from the combined teachings of
Hara, Kawamura, and Fairbairn by the argument that the claimed load lock
gas supply and associated load lock operational features, as argued, are not
suggested, to one of ordinary skill in the art, by the applied references.

ORDER
The Examiner’s decision to reject claims 1, 3, 4, 6-8, 10, and 12-15
under 35 U.S.C. § 103(a) as being unpatentable over Hara in view of
Kawamura, and Fairbairn is affirmed.
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No time period for taking any subsequent action in connection with
this appeal may be extended under 37 CFR § 1.136(a)(1)(v).

AFFIRMED

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