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 Rejections - 35 USC § 112
The rejection of claim 14 under 35 USC 112(b) is overcome by amendment, and that rejection is withdrawn.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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 9-10, 12-13, 16, 21-24, 26, and 28-31 are rejected under 35 U.S.C. 103 as being unpatentable over Onoue (US 2016/0147139) in view of Bowering (US 2009/0159808).
Regarding Claims 9-10, 12-13, 16, 21-26, and 28-31, Onoue teaches a method of manufacturing a substrate with a multilayer reflective film comprising a substrate (paragraph [0077]), a multilayer reflective film (paragraph [0082]), a block layer (paragraph [0091]), an Ru protective film (paragraph [0107]), and an absorber film pattern (paragraph [0212-0124]). In Example 10, the multilayer reflective film was formed in the same manner as in Reference Example 1, Example 3, and Example 5: to a SiO2-TiO2 glass substrate with a backside conductive film, a multilayer reflective film of Mo and Si was deposited using ion beam, a 1 nm thick block layer was deposited using ion beam sputtering (Claim 26, 30), and a Ru protective film was formed on the metal layer, and then subjected to annealing so that the Si layer as the top surface of the multilayer reflective film is diffused into the metal layer to form a block layer (paragraph [0169-0194]). An absorber film of TaBN and TaBO was formed on the Ru protective film by ion beam sputtering to form a mask blank for EUV lithography (paragraph [0198]). Onoue further teaches the absorber film is dry etched through a resist to form an absorber film pattern (paragraph [0125]) (Claim 9, 21, 29). Onoue discloses the multilayer reflective film is deposited by ion beam sputtering (paragraph [0090]) and the block layer may be formed by various known methods which can form a thin film such as ion beam sputtering, a sputtering method, a reactive sputtering method, a vapor deposition method, and a vacuum vapor deposition method (paragraph [0101]) (Claim 12 and 13). Regarding the annealing process, Onoue only discloses the block layer as reacting with the topmost silicon layer (Claim 23, 24, 28, 31), thus the capping layer is substantially unchanged in thickness before and after the anneal process (paragraph [0198]) (Claim 16).
Onoue describes the block layer reacting with the topmost layer of the reflective multilayer film to form a silicide and is silent to the block layer reacting with the Ru protective film, thus satisfying the claimed diffusion barrier has a lower reactivity with the capping layer than the reflective multilayer stack (Claim 9, 10, 22).
Onoue teaches that the blocking layer is to prevent diffusion of Si from the multilayer mirror into the ruthenium protective film [0094-0095]. Bowering teaches that diffusion layers involved with Mo/Si multilayer mirror stacks can be composed of other materials such as SiC, SiB6 [0097], ZrN, or Zr [0040], which also have smoothing functions [0040], which would be of benefit to the mask of Onoue [0080, 0118, 0128]. Therefore, it would have been obvious at the time the invention was filed to have used SiC, SiB6 , ZrN, or Zr as the material of diffusion blocking layer (16) of Onoue with a reasonable expectation of success because Bowering teaches that they are suitable diffusion barrier materials and with an expectation of obtaining a desired smoothing effect (Claims 9, 21, 29).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Onoue (US 2016/0147139) in view of Bowering (US 2009/0159808) as applied to Claim 9 and further in view of Mikami (US 2013/0115547).
Regarding Claim 11, the discussion of Claim 9 is relied upon as above. Onoue is silent to whether the same chamber is used in the successive deposition processes.
However, Mikami discloses in Fig. 1 an EUV mask blank comprising a substrate 11, a reflective layer 12 for reflecting EUV light, an interlayer 13 of a double layer structure is formed which is composed of a first layer 14 containing the after-mentioned predetermined amounts of nitrogen and Si, and a second layer 15 containing the after-mentioned predetermined amounts of Ru, nitrogen and Si, a protective layer 16 for protecting the reflective layer, and an absorber layer 17 (paragraph [0038]). The reflective multilayer is composed of alternating Mo/Si films using an ion beam sputtering or magnetron sputtering method (paragraph [0046-0048]). The first layer 14 comprising silicon and nitrogen is formed by slightly nitriding the Si film topmost surface on the multilayer reflective film (paragraph [0067]). Mikami further discloses that the deposition of the multilayer reflective layer and exposing the Si film surface to the nitrogen-containing atmosphere are carried out using the same chamber (paragraph [0069]) (Claim 11).
It would have been obvious for one of ordinary skill in the art to have modified the successive deposition processes of the reflective multilayer and the adhesion layer of Onoue to be performed in the same chamber as suggested by Mikami. One of ordinary skill would reasonably expect modifying Onoue to successively deposit layers in the same chamber to result in an EUV mask with similar properties.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Onoue (US 2016/0147139) in view of Bowering (US 2009/0159808) as applied to Claim 9 in view of Tsai (US 2015/0221514) or Ichikawa (WO 2021230297, English equivalent document used in lieu of English translation US 2023/0176467).
Regarding Claim 14, the discussion of Claim 9 is relied upon as above. Onoue further discloses the absorber film may be removed by dry etching using chlorine or fluorine gas (paragraph [0126], [0144]). The masks were RCA cleaned after etching (paragraph [0208]).
Onoue, is silent to etching using electron beam by using NOCl as precursor gas.
However, Tsai teaches a process for fabricating an integrated circuit using charged particle to pattern a structure on a hard mask (abstract). The patterning step involves flowing chlorine-based precursors such as nitrosyl chloride (NOCl) and exposing the hard mask to charged particles carried by a charged particle beam (paragraph [0019-0020]). The charged particle beam is interpreted as an electron beam. As shown by Fig. 2 and Fig. 3, the precursor gas 146 in combination with the charged particle beam is able to pattern the hard mask layer 10 to form the gap 14. After forming the pattern, other various processed may be performed such as pattern transfer (etching, deposition, lift off etc.) (paragraph [0024]).
Tsai discloses an alternative method of forming a gap (or pattern) in a hard mask layer using electron beam with NOCl precursor gas and after forming a gap, further pattern transfer steps may be applied. It would have been obvious for one of ordinary skill in the art to have modified the etching step of the absorber layer in Onoue with the charged particle exposure and NOCl patterning step of Tsai. Furthermore, Onoue specifically disclose the use of chlorine-based etchant gases and the etching steps are capable of patterning a layer. One of ordinary skill would reasonably expect this modification to capably etch the absorber layer resulting in a pattern to be transferred to layers underneath the absorber layer.
Alternatively, Ichikawa discloses a reflective mask blank in which a fine absorption film pattern is formed even when a high-absorbent material is used as an absorption film of an EUV mask (abstract). As a result, the showing effect can be reduced and electron beam repair etching can be performed (paragraph [0015]). During electron beam repair etching, a place to be etched is irradiated with an electron beam while supplying an etching gas to accelerated the reactivity of the etchant (paragraph [0063]). Ichikawa discloses that when the protective film is etched in the electron beam repair etching by a fluorine-based gas, a chlorine-based gas like NOCl is also usable (paragraph [0063-0065]). Furthermore, side etching is suppressed (paragraph [0063-0065]).
It would have been obvious for one of ordinary skill in the art to have modified the method of etching in Onoue with an electron beam repair etching using NOCl as the chlorine based etching gas of Ichikawa. All the reference demonstrate etching processes of absorber layers to pattern the absorber layer. One of ordinary skill would have been motivated to make this modification to suppress side etching as suggested by Ichikawa.
Claims 15 is rejected under 35 U.S.C. 103 as being unpatentable over Onoue (US 2016/0147139) in view of Bowering (US 2009/0159808) as applied to Claim 9 in view of Tanabe (US 2019/0086791) or Suzuki (WO 2021/200325, English equivalent document used in lieu of English translation US 2023/0133304).
Regarding Claim 15, the discussion of Claim 9 is relied upon as above.
Onoue further discloses the absorber film may be removed by dry etching using chlorine or fluorine gas (paragraph [0126], [0144]). The masks were RCA cleaned after etching (paragraph [0208]).
Onoue is silent to applying sulfuric peroxide mixture cleaning solution on the absorber layer after performing chloride or fluoride based dry etching.
However, Tanabe discloses a reflective mask blank with a reflective layer and an absorber layer (abstract). In the production of a reflective mask 20 which is described later (see FIG. 7), the absorber layer 14 is exposed to the cleaning liquid such as SPM when a resist pattern 181 (see FIG. 8) remaining in the reflective mask blank after etching is removed with a cleaning liquid (paragraph [0054-0055]). Furthermore, the absorber layer is processed by dry etching using chlorine or fluorine based gas (paragraph [0056]). Cleaning with SPM is further necessary for completely removing the resist residue (paragraph [0061]).
It would have been obvious for one of ordinary skill in the art to have modified the absorber layer etching step with the absorber etching and cleaning step using SPM of Tanabe. One of ordinary skill would have been motivated to make this modification to remove the remaining resist pattern as suggested by Tanabe.
However, Suzuki teaches a reflective mask having high resistance to an etching gas used for etching an absorber film (abstract). Suzuki teaches since the protective film contains ruthenium, etching resistance of the protective film to a mixed gas or chlorine-based gas, fluorine-based gas, and sulfuric acid peroxide (SPM) cleaning resistance are improved (paragraph [0073]). The reflective mask in Fib. 5D comprises a substrate 10, a reflective multilayer 12, a protective film 14, an patterned absorber film 24d (paragraph [0112]).
It would have been obvious for one of ordinary skill in the art to have modified the absorber etching steps of Onoue with a cleaning step using SPM as disclosed in Suzuki. Onoue contains a protective layer comprising Ru, and Suzuki teaches that the protective layer comprising ruthenium has good cleaning resistance to SPM. One of ordinary skill would have been motivated to make this modification since ruthenium protecting layers has improved SPM cleaning resistance as suggested by Suzuki.
Claims 17 and 27 are rejected under 35 U.S.C. 103 as being unpatentable over Onoue (US 2016/0147139) in view of Bowering (US 2009/0159808) as applied to Claims 9 and 21 in view of Montcalm (US Patent No. 5,958,605).
Regarding Claims 17 and 27, the discussion of Claims 9 and 21 are relied upon as above.
Onoue discloses the block film has a thickness of 1 nm (paragraph [0169-0194]).
Onoue is silent to embodiments where molybdenum is the topmost layer of the reflective multilayer stack.
However, Montcalm discloses a passivating overcoat bilayer used for multilayer reflective coatings for EUV to prevent oxidation and corrosion of the multilayer coating, thereby improving EUV optical performance (abstract). The overcoat bilayer prevents oxidation and corrosion of the multilayer coating (Col 1 Ln 66 to Col 2 Line 2). Montcalm discloses examples of the overcoat bilayer for C, B-4C, BN on silicon as well as C on Mo (Col 4 Ln 65 to Col 5 Ln 8). Fig. 2 shows the peak reflectivity of the Mo-Si multilayer at 5.0 degrees from normal incidence as a function of thickness. As seen in Fig. 2, at a thickness of 1 nm, the peak reflectivity of each material is around the same value. Furthermore, the C on Mo examples utilized an uppermost molybdenum layer in the multilayer reflective film.
It would have been obvious for one of ordinary skill in the art to have modified the block layer of Onoue to be on a Mo top layer of Montcalm. The block layers of Onoue the overcoat layers of Montcalm both perform the function of protecting the multilayer coating. One of ordinary skill would reasonably expect this modification to prevent oxidation and corrosion of the multilayer coating as suggested by Montcalm.
Claim 32 is rejected under 35 U.S.C. 103 as being unpatentable over Onoue (US 2016/0147139) in view of Bowering (US 2009/0159808) as applied to Claim 9 in view of Lin (US 2021/0063865).
Onoue and Bowering are discussed above. They do not teach that the capping layer is RuNb with 20% Nb. However, Lin teaches that the capping layer for an EUV mask may comprise Ru doped with 0-33% Nb to prevent accumulation of carbon in the capping layer during the use of the EUV mask [0027-0028]. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have used Ru doped with 0-33% Nb, such as 20%, in order to have prevented accumulation of carbon in the capping layer.
Response to Arguments
Applicant’s arguments, see pp. 2-10, filed 10/20/25, with respect to the rejections under 35 USC 102 and 103 have been fully considered and are persuasive in view of the amendment. However, upon further consideration, a new ground(s) of rejection is made in view of Bowering, as discussed above.
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.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Singh (US 2003/0043456) teaches protective capping layers of B, Ru, Rh, C, Si3N4, SiC, in addition to protecting the mirrors from environmental attack, may serve to improve the reflectivity characteristics (abstract).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHAEL B CLEVELAND whose telephone number is (571)272-1418. The examiner can normally be reached Monday-Friday; 9:00 am - 5:30 pm.
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/MICHAEL B CLEVELAND/ Supervisory Patent Examiner, Art Unit 1712
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