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 .
Response to Arguments
Applicant’s cancellation of claims 2-4, 10-13, and 16-20, as well as the Applicant’s addition of claims 21-33 is acknowledged.
Applicant’s arguments, see pages 9-12, filed 11 March 2026, with respect to the rejection(s) of claim(s) 1, 5, and 8 under 35 U.S.C. 102(a)(1) 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 Therefore, the rejection has been withdrawn.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 US 20230288794 A1 (hereby referred to as Akagi).
Applicant has amended independent claims 1, 5, and 8 to recite that the first metal of the protective film is at least one selected from iridium (Ir) and rhodium (Rh) and the second metal of the protective film is at least one selected from Zr, Ru, Y, La, Nb, Rb, and Ti. The independent claims also now recite that the content of the first metal is greater than the content of the second metal. The Applicant argues that the amendments to the independent claims overcome the previous prior art rejection under 35 U.S.C. 102(a)(1) as being anticipated by Onoue, due to Onoue failing to disclose a protective layer comprising Rh and Ru, wherein the contents of the Rh and Ru are disclosed. In other words, Applicant argues that Onoue fails to teach a protective film comprising a first metal that is either Ir or Rh and a second metal chosen from the list of elements stated above, wherein the content of the first metal is greater than the content of the second metal. Upon further review of the previously cited prior art, the Applicant’s arguments are found to be persuasive and therefore the previous rejection is withdrawn. However, a new rejection is presented in view of US 20230288794 A1 (hereby referred to as Akagi), as explained below.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim(s) 1, 5-6, 8, 14, 21-22, 24-25, and 27-28 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by US 20230288794 A1 (hereby referred to as Akagi).
The Examiner notes that whilst Akagi has a publication date of 14 September 2023, Akagi claims priority from JP 2020-201198 and thus has an effective filing date of 3 December 2020, which is earlier than the effective filing date of the instant application. Therefore, Akagi qualifies as prior art per 35 U.S.C. 102(a)(2).
Regarding Claims 1, 5, and 8, Akagi discloses a reflection mask blank for EUV lithography, a mask formed from the same, and manufacturing methods for both. The mask blank comprises a substrate (11), a reflective multilayer film (12), a protective film (13), and an absorption layer (14) (Akagi, paragraph 0048 and Fig. 1). The protective film includes rhodium (Rh) or a rhodium material containing Rh and at least one element selected from the group consisting of nitrogen (N), oxygen (O), carbon (C), boron (B), ruthenium (Ru), niobium (Nb), molybdenum (Mo), tantalum (Ta), iridium (Ir), palladium (Pd), zirconium (Zr), and titanium (Ti) (Akagi, paragraph 0059). The content ratio of Rh and the additional element forming an alloy (the ratio being Rh:X), based on atomic%, is 99:1 to 1:1 (Akagi, paragraph 0067). Akagi discloses inventive examples wherein a mask blank is formed, the mask blank comprising a substrate that is provided with a multilayer reflective film, a protective film, and an absorber film (Akagi, Example 1, paragraphs 0121-0144). Notably, Example 3 of Akagi provides a mask blank having a substrate, a multilayer reflective film, a protective film formed of an RhRu alloy, and an absorber film (Akagi, paragraph 0209-0218). The RhRu protective film of Akagi’s Example 3 comprises 75 atomic% Rh and 25 atomic% Ru (Akagi, paragraph 0217). The EUV reflective mask is formed by patterning the absorption layer of the EUV mask blank to form a pattern (Akagi, paragraph 0119). Whilst not explicitly stated by Akagi, rhodium (Rh) has a standard free energy of formation of a fluoride that is higher than the standard free energy of formation of RuF5, per the Applicant’s own admission (refer to paragraph 0046-0049 of the instant application’s specification). Specifically, the Applicant states that the fluoride of rhodium (RhF3) has a standard free energy of formation of -551 kJ/mol (see Table 1 of the instant application’s specification), whereas RuF5 has a standard free energy of formation of -948 kJ/mol (see paragraph 0046 of the instant application’s specification). Similarly, Akagi does not explicitly disclose the extinction coefficient at a wavelength of 13.5 nm of the second metal (ruthenium (Ru)). However, the Applicant states that ruthenium (Ru) has an extinction coefficient at a wavelength of 13.5 nm of 0.017 (see paragraph 0049 and Table 2 of the instant application’s specification). Thus, whilst Akagi does not disclose explicitly the properties of the first and second metal (rhodium (Rh) and ruthenium (Ru), respectively) of the protective film, the criteria of the first and second metals recited by instant claims 1, 5, and 8 are expected to be satisfied by Akagi’s protective film, per the Applicant’s own admission that rhodium and ruthenium satisfy the first and second metal criteria. Therefore, Akagi anticipates the invention of instant claims 1, 5, and 8.
Regarding Claims 6 and 14, Akagi discloses that the mask blank and mask of Example 3, which comprises the RhRu protective layer, may have an absorption layer comprising a film formed of either RuON or TaN (Akagi, paragraph 0218).
Regarding Claims 21-22, 24-25, and 27-28, the protective film disclosed in Example 3 of Akagi comprises 75 atomic% rhodium (Rh) and 25 atomic% ruthenium (Ru) (Akagi, paragraph 0217). Thus, the first metal content is 50 atomic% or more and the second metal content is less than 50 atomic%.
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) 7 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over US 20230288794 A1 (hereby referred to as Akagi) in view of US 20120021344 A1 (hereby referred to as Matsuo).
Regarding Claims 7 and 15, as discussed above, Akagi discloses a reflective mask blank and a reflective mask according to instant claims 5 and 8, respectively. Akagi discloses an absorber layer including ruthenium (Ru), but is silent in regards to a multilayer absorber layer comprising a buffer layer and an absorption layer.
Matsuo teaches a reflective mask blank and a reflective mask. The reflective mask blank comprises a substrate (1), a multilayered reflective film (2) formed on the substrate, a capping film (3) formed on the multilayered reflective film, a buffer layer (4) formed on the capping film, and two absorption films (5a and 5b) formed over the buffer film (Matsuo, paragraph 0103 and Fig. 11). A reflective mask is formed by patterning the absorption layers and the buffer film (Matsuo, paragraph 0108 and Fig. 12). The capping film acts to protect the multilayer reflective film (Matsuo, paragraph 0103 and 0106). In some embodiments, the lower absorption film acts as a buffer film (Matsuo, paragraph 0107), indicating that in such embodiments the buffer film (4) is not present, as absorption layer (5a) fulfills the purpose. Matsuo teaches embodiments wherein the lower absorption film (5a), which corresponds to the claimed buffer layer, is formed of tantalum (Ta) compounds, such as TaSi and TaN (Matsuo, paragraph 0133 and Fig. 20). In the same embodiments, the upper absorption film (5b), which corresponds to the claimed absorption layer, is formed of ruthenium (Ru) compounds (Matsuo, paragraph 0133 and Fig. 20).
Akagi and Matsuo are analogous art because both references pertain to reflective mask blanks and their manufacture. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to replace the absorber film disclosed by Akagi with a multilayer absorber film comprising a lower layer formed of a tantalum-based compound and an upper layer formed of a ruthenium-based compound, as taught by Matsuo, because such a multilayer absorber film produces a 180-degree phase difference and provides relatively low reflectance of the absorber film (see Matsuo, Fig. 20). The multilayer absorber film comprising a lower tantalum-based layer and an upper ruthenium-based layer reduces the reflectance of the reflection mask with reference to EUV light and is durable against chemical liquids, making the reflective mask favorable for use as a half tone mask (Matsuo, paragraph 0132-0133).
Claim(s) 23, 26, and 29-33 are rejected under 35 U.S.C. 103 as being unpatentable over US 20230288794 A1 (hereby referred to as Akagi).
Regarding Claims 23, 26, and 29, Akagi discloses a mask and a mask blank according to instant claims 1, 5, and 8, wherein the protective film comprises RhRu in a ratio of 75 atomic% to 25 atomic% (Akagi, Example 3 paragraphs 0209-0218). Akagi does not explicitly disclose an embodiment wherein the protective film includes rhodium, a second metal, and nitrogen. However, the broader disclosure of Akagi discloses that the protective film may contain at least one element (Y) selected from the groups consisting of N, O, C, and B in addition to Rh and the second metal (Akagi, paragraph 0069). When such an element Y is included in the rhodium alloy, the content of Rh and the second metal is 40 atomic% or more and 99 atomic% or less and the content of the element Y is 1 atomic% or more and 60 atomic% or less (Akagi, paragraph 0070). It is preferred that the content of the element Y is 1 atomic% or more and 20 atomic% or less (Akagi, paragraph 0070). Thus, it would have been obvious to one having ordinary skill in the art before the filing date of the instant application to include nitrogen (N) in the RhRu protective film of Example 3 of Akagi, wherein the nitrogen content is 1 atomic% to 20 atomic%, because the inclusion of nitrogen (and other similar light elements) increases the smoothness of the protective film formed (Akagi, paragraph 0069). Refer to MPEP 2143 I. A.
Regarding Claims 30-32, Akagi discloses a mask and a mask blank according to instant claims 1, 5, and 8, wherein the protective film comprises RhRu in a ratio of 75 atomic% to 25 atomic% (Akagi, Example 3 paragraphs 0209-0218). Akagi does not explicitly disclose an embodiment wherein the second metal is a combination of ruthenium (Ru) and niobium (Nb). However, the broader disclosure of Akagi discloses that the protective film may be a rhodium material contain Rh and at least one element selected from the group consisting of nitrogen (N), oxygen (O), carbon (C), boron (B), ruthenium (Ru), niobium (Nb), molybdenum (Mo), tantalum (Ta), iridium (Ir), palladium (Pd), zirconium (Zr), and titanium (Ti) (Akagi, paragraph 0059). In other words, Akagi teaches that the rhodium-based material used for the protective layer can comprise two or more elements in addition to the rhodium (Rh), and suitable options include ruthenium and niobium. Thus, it would have been obvious to one having ordinary skill in the art before the filing date of the instant application to replace the RhRu protective film of Example 3 of Akagi with a protective film comprising Rh, Ru, and Nb because Akagi suggests a rhodium-based film comprising two or more elements, including Ru and Nb (Akagi, paragraph 0059). Refer to MPEP 2143 I. E.
Regarding Claim 33, Akagi discloses a mask blank according to instant claim 1, wherein the protective film comprises RhRu in a ratio of 75 atomic% to 25 atomic% (Akagi, Example 3 paragraphs 0209-0218). Akagi does not explicitly disclose an embodiment wherein the protective film is the second metal is niobium (Nb). However, the broader disclosure of Akagi discloses that the protective film may be a rhodium material contain Rh and at least one element selected from the group consisting of nitrogen (N), oxygen (O), carbon (C), boron (B), ruthenium (Ru), niobium (Nb), molybdenum (Mo), tantalum (Ta), iridium (Ir), palladium (Pd), zirconium (Zr), and titanium (Ti) (Akagi, paragraph 0059). Further, Akagi teaches that the alloy of Rh and the other element have a content ratio (Rh:X), which is measured in atomic%, between 99:1 to 1:1 (Akagi, paragraph 0067). Thus, it would have been obvious to one having ordinary skill in the art before the filing date of the instant application to replace the RhRu protective layer taught by Example 3 of Akagi with a protective film comprising Rh and Nb because Akagi teaches that Ru and Nb are functional equivalents for the purposes of forming a protective layer out of a rhodium-based alloy (Akagi, paragraph 0059 and 0066). Refer to MPEP 2144.06 II.
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.
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/JAYSON D COSGROVE/Examiner, Art Unit 1737
/MARK F. HUFF/Supervisory Patent Examiner, Art Unit 1737
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