Prosecution Insights
Last updated: April 19, 2026
Application No. 18/276,789

REFLECTIVE PHOTOMASK BLANK AND REFLECTIVE PHOTOMASK

Non-Final OA §103
Filed
Aug 10, 2023
Examiner
FRASER, STEWART A
Art Unit
1724
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Tekscend Photomask Corp.
OA Round
1 (Non-Final)
86%
Grant Probability
Favorable
1-2
OA Rounds
2y 7m
To Grant
99%
With Interview

Examiner Intelligence

Grants 86% — above average
86%
Career Allow Rate
1135 granted / 1320 resolved
+21.0% vs TC avg
Moderate +14% lift
Without
With
+14.2%
Interview Lift
resolved cases with interview
Typical timeline
2y 7m
Avg Prosecution
45 currently pending
Career history
1365
Total Applications
across all art units

Statute-Specific Performance

§101
0.9%
-39.1% vs TC avg
§103
45.2%
+5.2% vs TC avg
§102
24.2%
-15.8% vs TC avg
§112
17.8%
-22.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1320 resolved cases

Office Action

§103
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 . This is the initial office action for US Patent Application No. 18/276789 by Gorai et al. Claims 1-8 are currently pending and have been fully considered. Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claims 1-8 are rejected under 35 U.S.C. 103 as being unpatentable over Ikebe (US 2022/0107557 A1). Regarding claims 1 and 5, Ikebe teaches (Figure 1, Abstract and [0064]) a reflective mask blank 100 for producing a reflective photomask for pattern transfer using an extreme ultraviolet light as a light source comprising a substrate 10; a reflective film 12 (reflective part) formed on the substrate and configured to reflect EUV light; and a layered film 16 (low reflective part formed on the reflective part and configured to absorb an incident light), wherein the layered film is a multi-layer structural body having at least two or more layers including a first layer 18 (absorption layer) and a second layer 20 (phase shift layer), the first layer and second layer are deposited in this order on the reflective film. PNG media_image1.png 284 416 media_image1.png Greyscale Ikebe indicates [0100] the first layer has an absolute reflectance of 2.5 percent or less and is therefore considered to be analogous to the claimed absorption layer. Ikebe further teaches [0222] the first layer may be configured to have an extinction coefficient k of greater than 0.041 when a layer including CoTa is employed (k = 0.047). In addition, Ikebe teaches [0122] the second layer may be configured to have a refractive index of 0.85 or more an extinction coefficient k of 0.1 or less, wherein the refractive index range and extinction coefficient range taught by Ikebe overlap the claimed ranges for the phase shift layer recited in claim 1. With further regard to claim 5, Ikebe teaches [0167-0169] a reflective mask can be formed from the reflective mask blank discussed above. As seen in Figures 3A-3H of Ikebe, the reflective mask blank may be subject to further etch processing to form a reflective mask (shown in Figure 3H). Although the refractive index and extinction coefficient values for the second layer taught by Ikebe do not anticipate Applicant’s claimed values, MPEP Chapter 2144.05 Section I states “In the case where the claimed ranges overlap or lie inside ranges disclosed by the prior art, a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990)”. Therefore, at the time of the filing date of the instant application, it would have been obvious to one of ordinary skill in the art to form a reflective mask blank and reflective mask, based on teachings of Ikebe, with the specified first and second layer configurations in order to improve the pattern formation capability of the reflective mask and reduce occurrences of reflected light defects during an EUV lithographic exposure process. Regarding claim 2, Ikebe teaches [0047] the first layer may be configured to include materials such as cobalt (Co) and nickel (Ni). Ikebe further teaches [0222] the first layer may include 50 atomic percent of Co when CoTa is included. Regarding claims 3 and 6, Ikebe teaches [0144] the second layer may be configured to include ruthenium (Ru). Ikebe indicates [0191 and 0210] the second layer may comprise an Ru based film that includes 80 atomic percent Ru. Regarding claims 4, 7 and 8, Ikebe teaches [0029] the reflectance properties of the reflective mask blank and reflective mask may be configured to be between 3 and 40 percent and the phase difference properties of the reflective mask blank and reflective mask may be configured to be between 160 and 200 degrees with respect to EUV light. Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEWART A FRASER whose telephone number is (571)270-5126. The examiner can normally be reached M-F, 7am-4pm, EST. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Miriam Stagg can be reached at 571-270-5256. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /STEWART A FRASER/Primary Examiner, Art Unit 1724
Read full office action

Prosecution Timeline

Aug 10, 2023
Application Filed
Mar 07, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
86%
Grant Probability
99%
With Interview (+14.2%)
2y 7m
Median Time to Grant
Low
PTA Risk
Based on 1320 resolved cases by this examiner. Grant probability derived from career allow rate.

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