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 .
Claim Status
Claims 1-12 and 14-20 are under consideration
Claim 13 is canceled
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-12, 14-15, and 17-20 are rejected under 35 U.S.C. 103 as being unpatentable over Ikebe (US20190384158A1, published 2019) in view of Nam (KR101485755B1, published 2014, references made to provided translation).
Regarding claims 1-12, 14-15, and 17-20,
Ikebe teaches a reflective mask blank comprising of a substrate, a multilayer reflective film formed on the substrate, and a phase shift film (thin film) formed on the multilayer reflective film [claim 1].
Ikebe teaches forming their phase shift mask using sputtering [0167], which would be expected to form an amorphous film, reading on instant claims 15 and 19.
Ikebe teaches their phase shift film may comprise of an MoTa alloy having a refractive index of 0.932 and extinction coefficient of 0.027 with EUV light (13.5 nm wavelength) [0102, 0106-0107, 0142], and may further contain at least one type of element selected from oxygen, nitrogen, carbon and boron [0120], reading on instant claims 5-6, 11-12, 17, and 20.
Ikebe teaches a surface roughness of the phase shift film after deposition in terms of the root mean square (RMS) roughness is even more preferably not more than 0.3 nm [0122], overlapping the range of instant claims 14 and 18. Per MPEP 2144.05, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists.
However, Ikebe fails to teach the at% of nitrogen when used in their alloy.
Nam, analogous art, teaches a blank mask (mask blank) comprising of a phase shift film 104 (phase reversal film) which may be formed of a material selected from the group consisting of Mo and Ta. The phase reversal film 104 may further include at least one of Silicon (Si), nitrogen (N), oxygen (O), and carbon (C), where the composition ratio of the phase reversal film 104 may be 3 at% to 50 at% for Mo, 30 at to 70 at% for Si, 0 at% to 50 at% for Ta, and N at 10 at% to 50 at% [0035-0037]. Examiner notes that the translation of paragraph [0036] of Nam seems to contain translation errors regarding the at% of each compositional component, and further references the original Korean Patent to confirm the at% ranges of each component.
For example, the Mo:Ta:Si:N composition may be 30 at% Mo : 30 at% Ta : 30 at% Si : 10 at% N, which reads on the at% ratios of instant claims 1-3 and 7-9.
As both Nam and Ikebe teach mask blanks comprising of a phase shift film, it would have been obvious to a person of ordinary skill in the art that using the above example composition of Nam for the phase shift film of Ikebe would result in a comparable and expected bask blank.
That is, the substitution of the phase shift film composition of Nam for the phase shift film of Ikebe, absent unexpected results, would have been obvious to one of ordinary skill in the art before the effective filing date of the instant application with the predictable result of forming a mask blank. The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395 – 97 (2007) (See MPEP § 2143, B).
Additionally, as both teach similar mask blanks, it would have been obvious to a person of ordinary skill in the art that using the at% of the Mo, Ta, and N components of Nam in the phase shift mask composition of Ikebe (which may be an MoTa alloy further comprising of nitrogen) would result in a comparable and expected mask blank, overlapping the at% ratios of instant claims 1-3 and 7-9, and further reading on instant claims 4 and 10.
That is, the substitution of the phase shift film component at% values of Nam for the phase shift film components of Ikebe, absent unexpected results, would have been obvious to one of ordinary skill in the art before the effective filing date of the instant application with the predictable result of forming a mask blank. The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395 – 97 (2007) (See MPEP § 2143, B).
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Ikebe (US20190384158A1, published 2019) in view of Nam (KR101485755B1, published 2014, references made to provided translation) as applied to claim 1 above, and further in view of Tanabe (US 20170363952 A1, published 2017).
Regarding claim 16,
Ikebe et al. teaches the above limitations set forth.
Ikebe teaches patterning their phase shift film [0055]. Ikebe further teaches an etching mask film formed on their phase shift film which enables the phase shift film to be etched with an etching gas (not having etching selectivity) [0123].
Ikebe fails to teach an etching mask film which contains chromium.
Tanabe, analogous art, teaches a mask blank comprising of an overlying etching mask film made of a material having etching selectivity (etching durability) in the etching of the light shielding film (which may contain Mo, Ta, and N), which may be made of chromium [0155-0156], reading on instant claim 16.
As both Ikebe and Tanabe teach mask blanks comprising of etching mask films formed over a film which may contain Mo, Ta, and N, it would have been obvious to a person of ordinary skill in the art to use the etching mask film of Tanabe in patterning the phase shift film of Ikebe in order to ensure good etching selectivity, to ensure a good pattern is formed.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Alexander Lee whose telephone number is (571)272-2261. The examiner can normally be reached M-Th 7:30-5:30 EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Keith Walker can be reached at (571) 272-3458. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Alexander N. Lee/Examiner, Art Unit 1737
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