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 § 103
Claims 17-18 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Wu (US Patent No. 7,771,895) in view of Mancini (US 2005/0079650), Wasson (US 20040175630), and Liu (US 20200098558).
Regarding Claim 17, Wu teaches an EUV photomask comprising a substrate 102, a multi-material layer 104, a capping layer 106, a multi-layer absorber layer where the multi-layer absorber layer comprises a self-mask layer 112 over the bulk absorber layer 110 (abstract, Fig. 1). The self-mask layer functions as a hard mask and may comprise TaSiON (Col 4, Ln 31-60). The multi-material layer 104 is described as an EUV reflective multi-material layer (Col 3, Ln 36-38). A photoresist 114 is deposited on the EUV mask and patterned to form an opening thereby exposing the hard mask layer (Col 3, Ln 32-35, Col 4, Ln 45-54) and the photoresist may be any suitable photoresist material such as electron-beam resist (Col 4, Ln 45-46). The hard mask layer is etched using the photoresist pattern as a mask (Col 4, Ln 54-64) and further the absorber layer is patterned using the hard mask layer as a mask (Col 5, Ln 48-53).
Wu does not teach forming an adhesion layer over a mask blank, etching through the adhesion layer, or wherein the photoresist layer has a higher adhesiveness to the adhesion layer than to the hard mask layer. Further, Wu is silent to a middle layer overlying the hard mask layer.
However, Mancini teaches semiconductor devices including an amorphous carbon layer for improved adhesion of organic layers and method of fabrication (abstract). Mancini discloses that to increase wettability and improve adhesion, a layer of amorphous carbon is deposited on the uppermost surface using typical semiconductor deposition techniques, such as PECVD or sputtering (paragraph [0017]). This deposition of amorphous carbon layer 16 results in an improved adhesive durability of a subsequently deposited photoresist, to low surface energy material layer 14, allowing low surface energy material 14 to be processed and patterned with conventional photoresist and etching processing techniques (paragraph [0019]). The carbon layer is disclosed as formed of a thin layer of amorphous carbon and may have a thickness in the range of 30 to 10,000 angstrom (3 to 1000 nm) (paragraph [0025]). Furthermore, two types of amorphous carbon are disclosed as suitable for fabrication of carbon layer 16. More particularly a polymer-like carbon material (PLC) (equivalent to the organic polymer and a diamond-like carbon (DLC) material, are disclosed for carbon layer 16 (paragraph [0025]). In a preferred embodiment, polymer-like carbon material is described as being about 60% polymeric, containing an appreciable amount of hydrogen, having a low density value (paragraph [0025]).
Regarding the adhesion layer, Wu discloses methods of forming a mask blank comprising using a photoresist pattern as a mask for etching, and Mancini discloses adhesion layers comprising amorphous carbon, such as polymer-like amorphous carbon, increase wettability and improve adhesion of lower layers to the photoresist. Since Mancini discloses the adhesion layer increases the adhesion of the uppermost surface and further improves adhesion to the photoresist, incorporating the adhesion layer would satisfy wherein the photoresist layer has a higher adhesiveness to the adhesion layer than to the hard mask layer.
It would have been obvious for one of ordinary skill in the art to have modified the mask blank of Wu with the adhesion layer comprising amorphous carbon of Mancini through routine experimentation. One of ordinary skill would have been motivated to make this modification to increase wettability of the lower layer and improve adhesion to the overlying photoresist as suggested by Mancini.
Mancini is silent to a middle layer overlying the hard mask layer.
However, Liu teaches that multilayer resists are of interest to reduce feature sizes [0002]. In this case, the multilayer resist comprises hard mask 204 [0016] and middle layer 208 [0022-0023], followed by adhesion layer 210 [0027] to adhere photoresist 212 [0032]. See Fig. 4. Liu teaches that the middle layer may comprise silicon nitride [0023]. Therefore, it would have been obvious, before the instant filing date, to have provided the multilayer mask of Liu, including a middle layer of silicon nitride, as the particular mask of Wu in order to reduce the achievable feature sizes.
Wu nor Mancini teach obtaining a semiconductor wafer over which a photoresist layer is formed, and patterning the photoresist layer by using the reflective mask.
However, Wasson discloses the use of a reflective mask for patterning a photoresist on a wafer using a reflective mask using a lithography system, optics, a reflective mask, and a semiconductor wafer with a photoresist layer (paragraph [0018]). The reflective mask contains a substrate, a multilayer reflective layer, an absorber layer, and several other layers (paragraph [0011]). Light is collimated onto the mask and projected onto the semiconductor wafer and the photoresist layer (paragraph [0018]).
It would have been obvious for one of ordinary skill in the art to have used the photomask of Wu in order to pattern a photoresist layer on a semiconductor substrate as demonstrated by the use of the reflective mask in Wasson. Applying the method of Wasson to the photomask of Wu would predictably result in the capability to pattern a photoresist layer on a semiconductor substrate. One of ordinary skill would have been motivated to use the reflective mask of Wu to pattern a photoresist on a semiconductor substrate as demonstrated by Wasson.
Regarding Claim 18, the discussion of Claim 17 is relied upon as above. Wu further discloses the self-mask layer functions as a hard mask and may comprise TaSiON (Col 4, Ln 31-60). Liu teaches that the middle layer may comprise silicon nitride. The adhesion layer of Mancini comprises amorphous carbon, and the self-mask layer and middle layer do not comprise carbon. Therefore, the adhesion layer comprises more carbon than the hard-mask layer or middle layer.
Regarding Claim 20, the discussion of Claim 18 is relied upon as above. Wu further discloses the bulk absorber layer 110 may comprise tantalum-based materials with essentially no oxygen, such as tantalum silicide-based materials such as TaSi (Col 4, Ln 12-17). Liu teaches that the middle layer may comprise spin on glass [0023] (interpreted as polysiloxane) as an intermediate layer Thus, Liu discloses the middle layer may be spin on glass, which is interpreted as the claimed polysiloxane; the polysiloxane contains silicon which is further contained in the absorber layer of Wu as described above.
Claims 20 is rejected under 35 U.S.C. 103 as being unpatentable over Wu (US Patent No. 7,771,895) in view of Mancini (US 2005/0079650), Wasson (US 20040175630), and Liu (US 20200098558) as evidenced by Hashimoto ‘951 (US Patent No. 4,936,951).
Wu further discloses the bulk absorber layer 110 may comprise tantalum-based materials with essentially no oxygen, such as tantalum silicide-based materials such as TaSi (Col 4, Ln 12-17).
Liu teaches that the middle layer may comprise spin on glass [0023] (interpreted as polysiloxane) as an intermediate layer Thus, Liu discloses the middle layer may be spin on glass, which is interpreted as the claimed polysiloxane; the polysiloxane contains silicon which is further contained in the absorber layer of Wu as described above. As evidenced by Hashimoto ‘951, an organic polysiloxane film is referred to a SOG or spin-on-glass (Col 1, Ln 25-26), and as such the spin on glass of Hashimoto is equivalent to a polysiloxane.
Allowable Subject Matter
Claims 1-4, 6-16, and 22 are allowed.
Claim 23 is objected to as being dependent upon a rejected base claim but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
Claim 1: The prior art does not fairly teach or suggest a method of manufacturing a reflective mask via the patterning method of claim 1, using an adhesion layer to attach the claimed mask blank to a photoresist layer, wherein the adhesion layer contains carbon nanoparticles dispersed in a polymer and is more than 90% carbon.
Claim 8: The prior art does not fairly teach or suggest a method of manufacturing a reflective mask via the patterning method of claim 8, using an adhesion layer to attach the claimed mask blank to a photoresist layer, wherein the adhesion layer comprises graphene.
Claim 23: The prior art does not fairly teach or suggest a method of manufacturing a semiconductor device via the patterning method of claim 17, using an adhesion layer to attach a middle layer that is disposed on a mask blank to a photoresist layer, wherein the adhesion layer comprises graphene.
Response to Arguments
Applicant’s arguments, see pp. 7-8, filed 12/9/25, with respect to claims 1 and 8 have been fully considered and are persuasive. The art rejections of claims 1-4 and 6-16 have been withdrawn.
Applicant’s arguments, see p. 8, filed 12/9/25, with respect to the rejection(s) of claim(s) claim 17 under 35 USC 103 have been fully considered and are persuasive in view of the amendment. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of the newly cited Wu, Mancini, and Wasson in view of the newly-cited Liu reference, required by amendment, and which teaches a silicon nitride middle layer.
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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/MICHAEL B CLEVELAND/ Supervisory Patent Examiner, Art Unit 1712
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