DETAILED ACTION
Response to Amendment
The amendment filed 6/15/2026 for US Patent Application No. 18/276789 has been entered and fully considered.
Claims 1, 2, 4, 5 and 7 are currently pending and have been fully considered. Claims 3, 6 and 8 have been cancelled.
Response to Arguments
Applicant’s arguments, see Remarks page 5, filed 6/15/2026, with respect to the 35 U.S.C. rejection of claims 1-8 as being unpatentable over Ikebe (US 2022/0107557 A1) have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Ikebe et al. (US 2021/0223681 A1).
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, 2, 4, 5 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Ikebe (US 2022/0107557 A1) in view of Ikebe et al. (US 2021/0223681 A1), herein referred to as Ikebe ‘681. Ikebe ’681 is listed in Applicant’s IDS filed 8/10/2023.
Regarding amended 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 amended claim 1.
With further regard to amended 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).
Ikebe does not appear to explicitly teach the limitations of amended claims 1 and 5 of the phase shift layer containing a total of 50 atomic percent or more of at least one of molybdenum or niobium. However, from the same field of technology, Ikebe ‘681 recites the formation of a reflective mask blank and a reflective mask for EUV lithography.
In view of amended claims 1 and 5, Ikebe ‘681 teaches (Figure 1 and [0047]) a reflective mask blank 100 comprising a mask blank substrate 1, a multilayer reflective film 2, a protective film 3, and a phase shift film 4 (a lower layer 41 and an upper layer 42) that are layered in this order.
PNG
media_image2.png
248
524
media_image2.png
Greyscale
The multilayer reflective film 2 reflects EUV light that is exposure light formed on a side of a first main surface (a front surface). The protective film 3 is provided to protect the multilayer reflective film 2 and is formed of a material having resistance to an etchant and a cleaning liquid used when the phase shift film 4 is patterned. The phase shift film 4 absorbs EUV light.
Ikebe ‘681 further teaches [0091, 0093 and 0100] the upper layer (also referred to as the second layer in Ikebe ‘681) of the phase shift film may be configured to include ruthenium and an element such as niobium or molybdenum. Ikebe ‘681 also teaches binary materials such as RuNb or RuMo may be used for the upper layer of the phase shift film. The aforementioned binary materials taught by Ikebe ‘681 are examples of materials that include 50 atomic percent or more of niobium and molybdenum.
Although the refractive index and extinction coefficient values for the second layer taught by Ikebe or Ikebe ‘681 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 and Ikebe ‘681, 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, the combination of Ikebe and Ikebe ‘681 teaches (Ikebe [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 4 and 7, the combination of Ikebe and Ikebe ‘681 teaches (Ikebe [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.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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
Prosecution Insights