Ex Parte Coon et al

Patent Trial and Appeal BoardDec 20, 2012

11878540 (P.T.A.B. Dec. 20, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte DEREK COON and ANDREW J. HAZELTON ____________ Appeal 2010-010394 Application 11/878,5401 Technology Center 2800 ____________ Before MARC S. HOFF, GREGORY J. GONSALVES, and ANDREW J. DILLON, Administrative Patent Judges. HOFF, Administrative Patent Judge. DECISION ON APPEAL Appellants appeal under 35 U.S.C. § 134(a) from a final rejection of claims 1-8 and 27-34.2 We have jurisdiction under 35 U.S.C. § 6(b). We reverse. STATEMENT OF THE CASE Appellants’ invention is an immersion lithography system having a fluid material in the space between a workpiece such as a wafer and the last- 1 The real party in interest is Nikon Corporation. 2 Claims 9-26 have been cancelled. Appeal 2010-010394 Application 11/878,540 2 stage optical member such as the lens of the optical system for projecting the image of a reticle onto the workpiece (Spec. 1). Appellants disclose a fluid control system to retain the fluid within and in the vicinity of the exposure area (Spec. 1-2). Pressurized gas is supplied from outlets 25 (Fig. 5) at sufficient velocity to confine the liquid (Spec. ¶¶ [0031], [0032]). Independent claim 1, reproduced below, is representative of the subject matter on appeal. 1. An immersion lithography apparatus comprising: an optical member, a gap defined between the optical member and a surface disposed opposite the optical member being filled with an immersion liquid; and a fluid control device including a gas outlet through which a gas is supplied to prevent the immersion liquid from entering a surrounding area external to an exposure area, wherein a flow velocity of the gas supplied from the gas outlet is determined based on a contact angle between the immersion liquid and the surface. REFERENCE Lof US 7,081,943 B2 July 25, 2006 REJECTIONS Claims 1-6, 8, 27-32, and 34 stand rejected under 35 U.S.C. § 102(e) as being anticipated by Lof. Claims 7 and 33 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Lof. ISSUE Appellants contend that Lof does not teach, expressly or inherently, determining a flow velocity of the gas supplied from the gas outlet based on Appeal 2010-010394 Application 11/878,540 3 a contact angle between the immersion liquid and the surface, as the independent claims recite (App. Br. 17). The Examiner finds that Lof’s teachings show that it would be necessary for Lof to consider the contact angle of the liquid and the surface (Ans. 4). Appellants’ arguments present us with the following issue: Does Lof teach, either expressly or inherently, determining a flow velocity of the gas supplied from the gas outlet based on a contact angle between the immersion liquid and the surface? PRINCIPLES OF LAW Under the doctrine of inherency, if a claimed element is not expressly disclosed in a prior art reference, the reference nevertheless anticipates the claim if the missing element is necessarily present in the reference, and it would be so recognized by skilled artisans. Rosco, Inc. v. Mirror Lite Co., 304 F.3d 1373, 1380 (Fed. Cir. 2002) (citations omitted). To anticipate the claim, the missing element must be necessarily present in the prior art—not merely probably or possibly present. Id. “Inherency, however, may not be established by probabilities or possibilities. The mere fact that a certain thing may result from a given set of circumstances is not sufficient.” In re Robertson, 169 F.3d 743, 745 (Fed. Cir. 1999) (citations omitted) (internal quotation marks omitted). ANALYSIS CLAIMS 1-6, 8, 27-32, AND 34 The independent claims recite a fluid control device including a gas outlet through which a gas is supplied to prevent immersion liquid from Appeal 2010-010394 Application 11/878,540 4 entering a surrounding area external to an exposure area (claim 1), wherein a flow velocity of the gas supplied from the gas outlet is determined based on a contact angle between the immersion liquid and the surface (claims 1 and 27). The Examiner finds that Lof inherently teaches that flow velocity is determined based on the contact angle between the immersion liquid and the surface. Lof teaches that “[t]he overpressure on the gas inlet 15, vacuum level on the outlet 14 and geometry of the gap are arranged so that there is a high-velocity gas flow inwards that confines the liquid” (col. 7, ll. 3-6). From that teaching, the Examiner finds that it would be necessary to take into consideration the contact angle of the liquid and the surface, since the contact angle is a measure of the degree of attraction, or confinement, of the liquid on the surface. This arrangement would require a high enough velocity gas flow in order to sufficiently confine the liquid within the exposure area. (Ans. 4). A finding of inherency requires that the missing element is necessarily present in the reference. See Rosco, 304 F.3d at 1380. The Examiner has provided argumentation, but not evidence, regarding the proposition that the contact angle between immersion liquid and the surface was necessarily considered in Lof. The Examiner provides no factual support for the assertion that it would be necessary to consider the contact angle of the liquid and the surface (see Reply Br. 4). We agree with Appellants that the Lof reference does not even discuss the contact angle (Reply Br. 2). In response to Appellants’ argument that Lof did not consider the contact angle, but merely chose a very high gas velocity (i.e., the speed of sound) (App. Br. 21; Lof col. 7, ll. 35-37), the Examiner argues that Lof’s Appeal 2010-010394 Application 11/878,540 5 choice of the speed of sound is only pertinent for its particular arrangement and is not applicable for other liquids or surfaces (Ans. 8). We are unpersuaded by the Examiner that this inapplicability supports an argument that the contact angle between immersion liquid and surface was necessarily considered in Lof. We find that the Examiner erred in rejecting claims 1-6, 8, 27-32, and 34 as being anticipated by Lof. We will not sustain the Examiner’s § 102 rejection. CLAIMS 7 AND 33 Claims 7 and 33 depend from claims 1 and 27 respectively. Accordingly, we will not sustain the § 103 rejection of claims 7 and 33, for the same reasons expressed supra with respect to parent claims 1 and 27. CONCLUSION Lof does not teach, either expressly or inherently, determining a flow velocity of the gas supplied from the gas outlet based on a contact angle between the immersion liquid and the surface. DECISION The Examiner’s decision rejecting claims 1-8 and 27-34 is reversed. REVERSED babc