DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
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) 1-20, is/are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication No. 2018/0149962 (hereinafter referred to as Kobayashi) in view of U. S. Patent Application Publication No. 2014/0272683 (hereinafter referred to as Yen).
Kobayashi, in [0001], discloses the reflective mask (photolithography reticle), and Kobayashi, in [0020], [0031], and [0037]-[0038], [0041], disclose a reflective mask, that includes a multilayer reflective film formed on the substrate, and forming an absorber film on the multilayer reflective film and patterning the absorber film to form a patterned absorber or an absorber pattern (claimed plurality of absorption structures, first or second) on the multilayer reflective film, and Kobayashi discloses in [0061], using the absorber pattern as the etch mask for etching during transferring of the pattern from the absorber layer to underlying film i.e., the absorber pattern can be transferred to the ML (multilayer stack) to form trench patterns in the reflective ML. Kobayashi, in [0116]-[0117], discloses that the multilayer reflective film is composed of alternately laminated high refractive index material and low refractive index material and that elements of different refractive indices are cyclically laminated. Kobayashi, discloses in [0118] that the cyclically laminated film is not limited to only one type of high index/low index pairs and that the lamination includes in addition to the Mo/Si as a pair, the cyclic lamination includes Ru/Si, Si/Mo/Ru, and the cyclic lamination of Si/Ru/Mo/Ru and is the same as the claimed first pair (Mo/Si) followed by Si/Ru, wherein the Molybdenum is the claimed first material, Silicon is the claimed second material, ruthenium is the claimed first process assistance layer, the third layer is silicon, the first and second sub-layers is the same as the cyclic laminate Ru/Si, the first, second and third sub-layer is the same as the cyclic laminate Si/Mo/Ru, and the cyclic laminate of Si/Ru/Mo/Ru is the same as the claimed third pair of layers and second process assistance layer, and the claimed first, second, third, fourth layer along with the cyclic deposition of Mo/Si produces the claimed fifth (Mo) and sixth layers (Si). Kobayashi teaches the same claimed cyclic laminates with different elements incorporated as the high index component of the pairs and different material included as the low index component of the pairs and will inherently be selectively etchable as recited. Kobayashi, in [0034], discloses the forming of a protective layer (buffer layer) on the multilayer reflective film and transferring the pattern of the absorber pattern to the protective film (buffer layer) using the etching mask so as to reveal the underlying ML stack that can be etched using the absorber pattern as the etching mask (claims 1-4, 12, 15-16, 18, 19). Kobayashi in [0118] teaches plural first sub-layers (Ru/Si, Mo/Be, Si/Nb), and plural second sub-layers (Mo compound/silicon compound, Si/Mo/Ru/Mo) such that the cyclic laminates are different from each other, and Kobayashi disclose Mo/Si with Ru/Si combination and is the same as the claimed first material Mo, second material Si, and first process assistance layer such as Ru or silicon compound (includes silicon dioxide). Kobayashi, [0119], discloses that the silicon film in the pairs have one thickness, and Mo film has one thickness and that each element in the corresponding cyclic laminate have a corresponding thickness i.e., the ¼ wavelength thickness of Ru is different than the ¼ wavelength thickness of either Mo or Si (claims 7-11, 20).
The difference between the claims and Kobayashi is that Kobayashi does not disclose the extending of the absorber structures into the ML pairs in the manner recited or including the absorber pattern material in the trenches (first or second or plural trenches). Kobayashi does not disclose the implanting of the dopants into the trench to form the absorption structures (claims 5-6, 13-14, 17, 19).
Yen, in the abstract, and in [0032]-[0033], discloses that the trenches are formed into the underlying reflective ML stack using the etching mask (hardmask pattern), and Yen, in [0024], [0033] discloses that the trenches formed in the underlying ML stack (reflective multilayer stack) can be of different depths depending on the etch process and the presence of the etch stop layer embedded in the ML layer i.e., the etching of the ML stack to form trenches of different depths can stop at the capping layer present in the underlying ML stack such as silicon compound or Ru, resulting in trenches in the ML stack at different depths. Yen, in [0033], [0035]-[0036], discloses the filling of the trenches formed with absorber structure i.e., absorber material wherein the absorber structure material includes dopant material (metal oxide particles such hafnium oxide, alumina) and that the underlying etch stop layer and capping layer in the ML stack prevent or block the further diffusion or implanting into the remaining underlying low index or high index layers such that the absorber layer formed in the trenches terminate at the Ru or silicon oxide layer (capping layer or etch stop layer) in the ML stack.
Therefore, it would be obvious to a skilled artisan to modify Kobayashi by using the absorber pattern/hardmask pattern to transfer the pattern into the multilayer reflective stack at different depths and forming absorber material into the different trenches formed in the multilayer reflective stack as taught by Yen because Kobayashi teaches etching the multilayer stack using the absorber pattern or the etching mask to transfer the pattern, wherein the reflective layer stack has mutually different etching properties, and Kobayashi does not prohibit the forming of different trenches of different depths and Yen teaches in [0033]-[0036], the use of the different materials in the ML stack such that the initial etching stops at a capping layer in the ML stack and the second etching stops at an etch stop layer in the ML stack and that doing so enables the formation of trenches of a targeted depths and the corresponding formation of absorption structures of different heights (in the trenches) and Yen, in [0039]-[0040], discloses that forming the absorption pattern as disclosed reduces process induced stress and enables a low cost process of forming absorber patterns of the EUV mask.
Response to Arguments
Applicant's arguments filed July 14, 2026, have been fully considered but they are not persuasive. With respect to applicant’s arguments that Kobayashi does not disclose the claimed first process assistance layer or the second pair of layers between two of the first pairs or that the first material and second material are selectively etchable with respect to the first process assistance layer, Kobayashi in [0114]-[0119], teaches the multilayer reflective stack is formed by alternately laminating a high refractive index layer and a low refractive index layer i.e., each pair forming an EUV mirror, and Kobayashi also teaches that the laminated elements (layers) of different refractive indices can be cyclically laminated as long as the multilayer reflective stack imparts the function of reflecting EUV light and does not limit the arrangement of the high refractive index and low refractive index materials, and also teaches that Mo film and Si film is preferably included in the laminated stack of the reflective layers, and then teaches including laminates of Ru/Si such that arrangement and configuration of the elements are not limited as long the stack reflects EUV light i.e., EUV mirror and includes the stack of Mo/Si/Ru/Si/Mo/Si since the stack lamination is a low index/high index stack sequence (discussed in [0114]), and includes the claimed stack in the independent claims i.e., a low index material such as Mo is the same as the claimed first material, the high index material such as Si is the claimed second material and Ru is of a lower refractive index than silicon and the laminate includes Ru/Si such that Ru is the same the claimed process assistance layer and Si (laminated atop Ru) is the claimed third layer of the second material on the process assistance layer and is the same as the claimed multilayer reflective stack recited. With respect to applicant’s argument that Kobayashi does not teach a process assistance layer, Kobayashi teaches a lamination of different materials, and as discussed in the preceding sentences, forms a laminate that imparts the function of a multilayer reflective stack that reflects EUV light. Also, nothing in the independent claims recite what the process assistance material or component or composition is. The third layer being a Ru (as suggested by Kobayashi as the laminate that can be used in the multilayer reflective stack) is not the same as the first material Mo or the second material Si and is laminated in the same claimed order and can function as an EUV mirror and is the same as the claimed process assistance layer that is deposited or laminated on the second layer of the second material of the first layer/second layer stack. Furthermore, Ruthenium is different than Mo and Si and thereby Mo and Si will easily be selectively etchable with respect to Ru. Also, nothing in the claims suggest or recite what the etching agent is or what components constitutes the etchant so as to be selectively etchable or not, and as recited in claim 10, the first material and second material and the first process assistance layer material are the same as the materials taught by Kobayashi and Kobayashi teaches the same claimed order of laminates that constitutes the multilayer reflective stack. With respect to applicant’s argument that Yen does not disclose the etch stop layer is part of the second pair of layers or that the third layer of the second material on the process assistance layer, Kobayashi is dependent upon to disclose the different elements that constitute the multilayer reflective stack, and is discussed in the preceding sentences, Yen is dependent upon to disclose the forming of trenches at different depths into the multilayer (ML) stack and the filling of the trenches with absorber material, and Yen does not limit the depth of the trench and easily includes the claimed depth of the absorption structures, and Yen does not require all the ML stack to have the etch stop layers and Yen does not limit the etch stop layer at a certain layer of the ML stack, since the etch depth is based on the targeted depth and can be controlled to achieve a target depth, and Yen, in [0041] discloses forming an absorption trench in the reflective ML.
Conclusion
THIS ACTION IS MADE FINAL. 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 Daborah Chacko-Davis whose telephone number is (571) 272-1380. The examiner can normally be reached on 9:30AM-6:00PM EST Mon-Fri. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sally A. Merkling can be reached on (571) 272-6297. The fax phone number for the organization where this application or proceeding is assigned is 571-272-8300. 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.
/DABORAH CHACKO-DAVIS/Primary Examiner, Art Unit 1737 September 15, 2026.
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