DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s election without traverse of Group II in the reply filed on 10/15/2025 is acknowledged.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 10-14, 39-41, and 43-49 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lalovic, et al (U.S. Patent Application Publication 2015/0070673 A1) in view of Barman, et al (U.S. Patent Publication 2014/0268083 A1).
Regarding claim 10, Lalovic discloses an optical system for deep ultraviolet (DUV) optical lithography, the optical system comprising:
A gas discharge system that includes one or more gas discharge chambers (500, 510), each gas discharge chamber housing an energy source (paragraphs 0069 and 0071 – pair of elongated electrodes) and containing a gas mixture that includes a gain medium (paragraphs 0069 and 0071); and
One or more optical components (515, 525, 530) associated with the gas discharge system.
Lalovic fails to teach wherein each optical component comprises a substrate comprising an atomically-smooth substrate surface that forms at least a portion of an optically-interacting surface, and a protective layer configured to mitigate or prevent damage of the atomically-smooth substrate surface caused at least in part by irradiation of DUV light, the protective layer deposited onto the atomically-smooth substrate surface to thereby form a smooth interface between the substrate and the protective layer.
Barman teaches an atomically-smooth optical component for use in DUV lithography apparatus such as Lalovic’s (paragraph 0063), comprising a substrate (204) comprising an atomically-smooth substrate surface (paragraph 0057) that forms at least a portion of an optically-interacting surface, and a protective layer (205) configured to mitigate or prevent damage of the atomically-smooth substrate surface to thereby form a smooth interface between the substrate and the protective layer (paragraphs 0045-0046).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to utilize Barman’s atomically-smooth optical component as one or more of the optical components in Lalovic’s apparatus, because Barman provides a teaching, suggestion, and/or motivation for using the atomically-smooth optical component in a DUV lithography apparatus like Lalovic’s (paragraph 0063).
Regarding claim 11, Lalovic’s gas discharge system comprises two discharge chambers including a master oscillator (500) configured to produce a pulsed seed light beam and a power amplifier (510) configured to produce a pulsed output light beam from the seed light beam.
Regarding claim 12, Lalovic discloses wherein at least on of the optical components is configured to feed the pulsed seed light beam from the master oscillator to the power amplifier (Fig. 5).
Regarding claim 13, Lalovic discloses wherein the optical component is a beam reverser (530) or a beam splitter (525).
Regarding claim 14, Barman’s atomically smooth optical component’s profile roughness parameter is within a range of 0.01 nm to and including 0.17 nm (paragraph 0047).
Regarding claims 39 and 44, a lack of defects, scratches, contaminant particles, and subsurface damage is inherent to an atomically-smooth surface such as that taught by Barman.
Regarding claim 40, Barman’s atomically-smooth substrate surface has an average peak-to-valley height profile within a range of 1.0 nm to 1.6 nm (paragraph 0047).
Regarding claim 41, Lalovic discloses a light beam that has a wavelength of 193 nm (paragraph 0070).
Regarding claim 43, Barman’s optical component is configured for a light beam that has a wavelength in the deep ultraviolet range (paragraph 0063).
Regarding claim 45, Lalovic discloses wherein at least one optical component is a transmissive optic (515, 525).
Regarding claim 46, Lalovic discloses wherein the gas mixture includes argon fluoride (paragraph 0070).
Regarding claim 47, Lalovic discloses wherein the energy source includes a pair of electrodes configured to form a potential difference that excites the gain medium of the gas mixture (paragraphs 0069 and 0071).
Regarding claim 48, Lalovic discloses wherein at least one optical component is a partially reflecting/partially transmitting optical coupler (525).
Regarding claim 49, Lalovic discloses wherein at least one optical component is arranged external to the gas discharge chamber (Fig. 5).
Allowable Subject Matter
Claim 42 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: The prior art fails to teach wherein, for each optical component, the substrate comprises a calcium fluoride substrate and the protective layer is configured to prevent the depletion of fluorine from the calcium fluoride substrate. Cangemi, et al (U.S. Patent Application Publication 2009/0141358 A1) teaches that calcium fluoride is a preferred substrate for a DUV optical element (abstract), but the prior art does not teach that the protective layer is configured to prevent the depletion of fluorine from the calcium fluoride substrate.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHAEL P MASKELL whose telephone number is (571)270-3210. The examiner can normally be reached M-F 10A-6P.
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/MICHAEL MASKELL/Primary Examiner, Art Unit 2881 13 December 2025