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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 02/07/2026 has been entered.
Response to Amendment
Applicant’s Amendment filed 12/15/2025 has been considered and is entered. Claim 1 has been amended. Claims 2-14 are either original or have been previously presented.
Response to Arguments
The rejections over 35 USC 112(b) have been rendered moot by the Amendment to claim 1. As such, these rejections are withdrawn.
Applicant’s Amendments and arguments based thereon have been considered and are discussed below.
The instant claim has been amended to recite that at least one of R4 represents an iodine, fluorine, or trifluoromethyl group. The prior art at various points teaches halogen. As has been reiterated at points in the body of the rejection below, “halogen” as a genus comprises only 5 members, of which only 4 are practical for use in standard chemistry as Astatine is both rare and has a half-life of 8.1 hours, preventing practical chemical use. As such, the genus only comprises fluorine, iodine, chlorine, and bromine. This genus is small enough that person having ordinary skill in the chemical arts would immediately envision all 4 members from the mention of “halogen”. As such, the scope of the prior art naturally teaches and suggests both/each of Iodine and Fluorine whenever it recites “Halogen”.
Regarding applicant’s assertion of unexpected results, the results proffered do appear to be of practical significance – however the scope of the examples provided are orders of magnitude narrower than that of the claims. It cannot be ascertained whether the entire scope of the claim – all claimed embodiments – would display the same unexpected results. If applicant wishes to Narrow the claims to better encompass the narrow scope of embodiments relied upon for allegations of unexpected results, they may do so at their convenience. Further, these results are not directly compared to the prior art proffered in the prior office action.
Regarding the arguments directed towards the reference Kurata and rejections based thereon, including those based on Kurata and secondary references, Kurata teaches a halogen embodiment that corresponds to claimed R4. As such, the rejection is maintained as per the species-genus argument given above. Pointing to individual examples in Kurata does not persuasively argue against the reference – patents are good for all they contain and the mere provision of individual examples does not discount or negate the sum teachings of a reference. The rejections over Kurata are maintained.
Regarding arguments towards the rejections over Hayoz et al and further rejections relying on Hayoz and secondary references, these rejections are withdrawn.
Regarding arguments directed towards Belfield and rejections based thereon, and towards rejections based on Belfield and further references, the office action relies on reasoning that related a substitution being present in one prior art reference could be combined/substituted into one compound as per another reference, not mere mixtures – predicated on the expectation that chemically similar compounds would be expected to function similarly. The arguments that the office has not provided evidence that the PAGS of Belfield would be sufficient for 2PA photoinitiators, in negative resist for photolithography, or 3-D microfabrication is not persuasive – the USPTO does not run a laboratory. A prima facie case of obviousness over chemical similarity was made in the prior office action, wherein it is assumed that the photoinitiators would at the very least function in a negative photoresist because they produce acid upon irradiation and the bedrock of photolithography functioning with a PAG relies on this property. Chemical similarity begets similar properties where invoked. The rejections over Belfield are maintained.
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 1-7, and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Kurata (JP 2008169231, reference citations from English translation).
Regarding Claims 1, 7 and 9, Kurata discloses triarylsulfonium photoacid generators of Chemical Formula 1 that provide good storage stability, high image quality, excellent curability and adhesion to a substrate (paragraphs [0005-0009]). Particular embodiments of the inventive salts are disclosed that contain thiophene functional groups (paragraph [0048-0080], referenced below). When any of the compounds represented by General Formula 1 are used, the adhesiveness of the cured product to a substrate is improved (paragraph 0034]). The photoacid generator is used in negative-active photoresists with an oxirane or oxetane crosslinker (paragraph [0215-0216]). Each of the salts below satisfy the claimed formula (I) where:
m1 is 1, m2 to m9 are 0.
A1 is C1 hydrocarbon where CH2 is replaced by -S- (1-15), C2 hydrocarbon (1-47, 1-63, 1-223), C2 hydrocarbon where C2H4 is replaced by -CO- and -O- (1-127), and C1 hydrocarbon where CH2 is replaced by -SO2- (1-175).
m1+m7=1, m2+m8=0, m3+m9=0, m1 represents an integer of 1 or more.
X7 is -CO-.
Kurata is silent to at least one of R4 represents an iodine, fluorine, or trifluoromethyl group, where m4 is 1 to 3 and where the counterion is an organic ion
However, Kurata further discloses the actinic radiation-curable composition comprises the sulfonium salt compound represented by formula (1) (paragraph [0007-0008]) wherein X is any group selected from (A-1) in chemical formula 2 (paragraph [0009]) and R3 is any group selected from the following group B-1 in chemical formula 3 (paragraph [0009-0012]). In the group B-1, RA represents substituents and HAr represents substituted or unsubstituted heteroaryl group (paragraph [0013]). The HAr group may be substituted and examples of the substituents include those defined for RA (paragraph [0030]); RA is any one of a halogen atom, an alkyl group, an alkoxy group, an alkylthio group, and an alkylamine group (paragraph [0015]). Adding the substitution would satisfy where m4 is 1. The genus of halogen contains 4 species for all practical matters – Iodine, Fluorine, Bromine, and Chlorine. Given the small size of the genus, a person having ordinary skill in the art would have been able to immediately envision each and every species encompassed by the genus “halogen”. The reference thus teaches that Ra is may be Iodine or Fluorine.
Kurata does not disclose all of the claimed limitations of the salt in one disclosed embodiment; however, Kurata may be relied upon for all that it discloses. Kurata discloses triphenylsulfonium salts having a linking group and thiophene groups heteroaromatic and further discloses the heteroaromatic groups may contain a halogen substituent. It is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose…[T]he idea of combining them flows logically from their having been individually taught in the prior art. In re Kerkhoven, 205 USPQ 1069 1072. In the instant case, it would have been obvious to one of ordinary skill in the art to obtain a composition comprising the claimed salt based on the disclosure of Kurata and arrive at the instant claims through routine experimentation.
Regarding the organic ion, Kurata further discloses that in Chemical Formula 1, Z- represents a counterion that can be BF4-. PF6-, AsF6-, and complex ions such as sulfonate ions such as p-CH3C6H4SO3- and CF3SO3- (paragraph [0046]). When any of the compounds represented by General Formula 1 are used, the adhesiveness of the cured product to a substrate is improved (paragraph 0034]).
Chemical Formula 1 discloses that Z- can have several equivalent counterions including a fluorinated sulfonate anion. It would have been obvious for one of ordinary skill to have modified the counterion to be a sulfonic acid counterion through routine experimentation. The counteranions in General Formula 1 are disclosed as equivalents to one another, therefore one of ordinary skill would expect the modification of one counteranion for another, such as the sulfonic acid anion, to produce similar properties such as improving adhesiveness of the cured product to the substrate as suggested by Kurata (Claim 7).
Kurata is silent to furan-containing substituents, such that any of X4 to X6 are -O-.
However, furan and thiophene are chemically similar heteroaromatic compounds, where both S and O are Group 16 chalcogens and therefore have similar chemical properties due to their outermost electron shell configuration. A prima facie case of obviousness may be made when chemical compounds have very close structural similarities and similar utilities. "An obviousness rejection based on similarity in chemical structure and function entails the motivation of one skilled in the art to make a claimed compound, in the expectation that compounds similar in structure will have similar properties." In re Payne, 606 F.2d 303, 313, 203 USPQ 245, 254 (CCPA 1979).
Therefore, it would have been obvious for one of ordinary skill to have modified the thiophene-containing heteroaromatic substituents with furan-containing heteroaromatic substituents through routine experimentation. Thiophene and furan each contain the Group 16 chalcogens O and S; one of ordinary skill would reasonably expect this modification to produce a furan-containing salt having substantially similar properties to a thiophene-containing salt.
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Regarding Claims 2-4, the discussion of Claim 1 is relied upon as above. Kurata further teaches salt 1-15 that satisfies where A1 is *-X01-L01-, X01 is -S- and L01 is a single bond. Kurata further teaches salt 1-127 that satisfies where A1 is *-L01-X01, X01 is -O- and L01 is a C1 alkanediyl where -CH2- is replaced by -CO-. Kurata further teaches salt 1-175 that satisfies where A1 is *-X01-L01-, X01 is -SO2- and L01 is a single bond. In all these cases, m2 and m3 are zero.
Regarding Claim 5, the discussion of Claim 1 is relied upon as above. Kurata further discloses in the group B-1, RA represents substituents and HAr represents substituted or unsubstituted heteroaryl group (paragraph [0013]). The HAr group may be substituted and examples of the substituents include those defined for RA (paragraph [0030]); RA is any one of a halogen atom, an alkyl group, an alkoxy group, an alkylthio group, and an alkylamine group (paragraph [0015]).
Regarding Claim 6, the discussion of Claim 1 is relied upon as above. Kurata further discloses in Chemical Formula 1 that R1 and R2 are substituents chosen from any halogen, alkyl, alkoxy, alkylthio, and alkylamino groups, R4 may be a substituent chosen from halogen, hydroxyl, alkyl, and alkoxy groups, and further that R3 may be represented by HAr where HAr is a substituted or unsubstituted heteroaromatic group (paragraph [0007-0017]). The substituents for HAr include those substituents defined for R1 and R2 (paragraph [0030]). Further, Kurata discloses examples having particular substituents such as, in this non-exhaustive list, linear and branched alkyl (structures 1-2 and 1-4, 1-16, 1-18, 1-32, 1-36, 1-49, 1-61 paragraph [0048-0056]), cycloaliphatic (structure 1-214, paragraph [0071]), alkoxy (structure 1-146, paragraph [0064-], halogen (structures 1-80, 1-185, paragraph [0056, 0068]), and thioalkyl groups (structure 1-166, paragraph [0066]). Furthermore, Kurata discloses examples of substituents on the HAr groups to be alkyl (structure 1-4, 1-274), aromatic (structure 1-276), chlorine (structure 1-280), thioalkyl (structure 1-281) (paragraph [0079]).
Claims 8, 10, and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Kurata (JP 2008169231, reference citations from English translation) as applied to Claims 1 and 9 in view of Li (US 2003/0008230).
Regarding Claims 7 and 8, the discussion of Claim 1 is relied upon as above. Kurata further discloses that in Chemical Formula 1, Z- represents a counterion that can be BF4-. PF6-, AsF6-, and complex ions such as sulfonate ions such as p-CH3C6H4SO3- and CF3SO3- (paragraph [0046]). When any of the compounds represented by General Formula 1 are used, the adhesiveness of the cured product to a substrate is improved (paragraph 0034]).
Kurata is silent to other sulfonic acid anions, sulfonylimide anions, or sulfonylmethide anions
However, Li teaches thiophene-containing photoacid generators comprising a counterion (abstract). The photoacid generators are sulfonium or iodonium cations with at least one thiophene or thiophene substituted with alkyl, alkoxy, or cycloalkyl (paragraph [0016-0017]). The anions disclosed may be perfluorinated alkyl sulfonate, perfluorinated aryl sulfonate, perfluorinated alkyl and aryl sulfonyl methide, perfluorinated alkyl and aryl sulfonyl imide and combinations thereof (paragraph [0017]). Example 1 demonstrates dimethyl-(2-thienyl)sulfonium perfluorobutanesulfonate salt (paragraph [0060]). Perfluorobutane sulfonate satisfies the anion of formula (I-A) where Q1 and Q2 are F, L1 is 2 carbon saturated hydrocarbon with all hydrogens replaced by F, and Y1 is a methyl group having 3 fluorine substituents. Additionally, thiophene PAGs absorb less light at 220 nm or less and may lead to photoresists exhibiting high resolution at lower wavelength (paragraph [0013]).
It would have been obvious for one of ordinary skill in the art to have modified the thiophene-containing sulfonium salts of Kurata with perfluorobutane sulfonate counterion disclosed by Li. Kurata discloses other fluorinated sulfonate counterions for the inventive photoacid generator compositions. One of ordinary skill in the art would expect substituting one sulfonate salt for another to produce a photoacid generator with substantially similar properties.
Regarding Claims 10 and 14, the discussion of Claim 1 is relied upon as above. Kurata further discloses the photoacid generator is used in negative-active photoresists with an oxirane or oxetane crosslinker (paragraph [0215-0216]). When any of the compounds represented by General Formula 1 are used, the adhesiveness of the cured product to a substrate is improved (paragraph 0034]).
Kurata is silent to a resist composition having a resin with an acid-labile group.
However, Li teaches thiophene-containing photoacid generators comprising a counterion and chemically amplified resist compositions containing a chemically amplified base polymer (abstract). Li teaches thiophene PAGs absorb less light at 220 nm or less and may lead to chemically amplified photoresists exhibiting high resolution at lower wavelength (paragraph [0013]). The base polymer of the resin may be positive or negative tone base polymer which may comprise conventional acid sensitive side chains that are bonded to the polymer backbone (paragraph [0023]). The photoacid generators are sulfonium or iodonium cations with at least one thiophene or thiophene substituted with alkyl, alkoxy, or cycloalkyl (paragraph [0016-0017]). Example 1 demonstrates dimethyl-(2-thienyl)sulfonium perfluorobutanesulfonate salt (paragraph [0060]); the photoacid generator is evaluated in a lithographic composition comprising the polymer resin Poly(1-methylcyclopentyl-5-norbornene-2-carboxylate-co-5-norbornene-2-spirolactone-co-5-norbornene-2-carboxylic acid) (paragraph [0064-0065]). The 1-methylcyclopentyl group is an acid-labile group.
Kurata and Li both demonstrate thiophene-containing photoacid generators used in negative-acting photoresist and chemically-amplified photoresists. Therefore, the thiophene-containing photoacid generators may be suitable for both negative-active and chemically-amplified photoresist compositions. Kurata and Li do not show a specific example of the claimed sulfonium salt in a resist composition comprising It would have been obvious for one of ordinary skill in the art to have combined the base polymer in Kurata with the acid-labile negative tone base polymer disclosed in Li. One of ordinary skill would have been motivated to make this modification since thiophene PAGs absorb less light at 220 nm or less and may lead to chemically amplified photoresist exhibiting high resolution at lower wavelength as suggested by Li.
Regarding Claim 14, the discussion of Claim 10 is relied upon as above. Li further discloses spin-coated the photoresist onto an antireflective material applied to silicon wafer, soft-based to produce a film, exposed to 193 nm radiation, post-exposure baked, and developed using aqueous TMAH developer (paragraph [0065]) (Claim 14).
Claim 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over Kurata (JP 2008169231, reference citations from English translation) as applied to Claim 1 in view of Li (US 2003/0008230) as applied to Claim 10 and further in view of Ayothi (US 2013/0052585).
Regarding Claims 11-13, the discussion of Claim 10 is relied upon as above.
Li teaches thiophene-containing photoacid generators comprising a counterion and chemically amplified resist compositions containing a chemically amplified base polymer (abstract). The chemically amplified polymer comprises an acid-labile group (paragraph [0064-0065]).
Kurata and Li are silent to the acid-labile groups comprising structural units (a1-0, a1-1 or a1-2) and a structural unit of (a2-A); further Kurata and Li are silent to the resist composition further comprising a salt generating an acid having an acidity lower than that of an acid generated by the acid generator.
Ayothi discloses photodecomposable bases with dicarboxylate anion groups that show increased imaging performance (abstract). Ayothi discloses that photodecomposable bases are photoactive additives used in chemically amplified photoresist formulations to improve photoresist properties; furthermore, photodecomposable bases in chemically amplified photoresists offer improved performance, formulation stability, and delay stability over conventional base quenchers (paragraph [0003]). Photodecomposable bases are generally added to photoresist compositions to improve resolution, linearity bias, and to stabilize latent images (paragraph [0003]) (Claim 13). Ayothi notes that the photoresist polymers are generally well known in the art, and are insoluble in aqueous base solution but in the presence of an acid, the polymers are catalytically deprotected such that they become soluble in an aqueous base solution (paragraph 0036]). In Table 1, Ayothi discloses Resist A-J comprising the polymers PHS-MAdMA and PHS-EAdMA, a photoacid generator and a photodecomposable base (PHS = polyhydroxystyrene, M/EAdMA = (m)ethyl-adamantyl methacrylate, paragraph [0070]). Ayothi additionally discloses that depending on the photoresist the exposure may form positive or negative patterns (paragraph [0051]).
The PHS-MAdMA polymers of Ayothi satisfies Claim 11 formula (a1-1) where Ra4 is methyl, La1 is -O-, Ra6 is methyl or ethyl, m1 is 0 and Claim 12 formula (a2-A) where Ra50 is hydrogen, Aa50 is a single bond, and mb is 0 (Claim 11-12).
Li and Ayothi both disclose chemically amplified resist compositions comprising an acid-labile group. It would have been obvious for one of ordinary skill in the art to have to have substituted the resist composition in Li for the polyhydroxystyrene-ethyl-adamantyl methacrylate resist composition in Ayothi through routine experimentation. Both resist compositions perform the same function in a chemically amplified photoresist, namely to be insoluble in aqueous base solution until acted upon by an acid. One of ordinary skill would reasonably expect substituting the base resin polymer to create a working chemically amplified resist composition with similar properties.
Furthermore, it would have been obvious for one of ordinary skill in the art to have modified Kurata and Li with the photodecomposable of Ayothi. One of ordinary skill would have been motivated to make this modification to improve resolution, linearity bias, and to stabilize latent images as suggested by Ayothi.
Claims 1-7, and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Belfield (US Patent No. 8,192,590) in view of Kurata (JP 2008169231, reference citations from English translation).
Regarding Claim 1, 7, and 9, Belfield discloses methods of preparing sulfonium photoacid generators by microwave-assisted reaction of diarylsulfides in the presence of alkrlaryliodonium salts for faster synthesis (abstract). An example of the photoacid generators is disclosed in Fig. 4, shown below. The sulfonium salt containing the thiophene group satisfies the salt represented by formula (I) wherein:
m1 is 1, m4 is 1, X4 is -S-, R4 is halogen
m2, m3, m5, and m6 to m9 are 0
A1 is a hydrocarbon group having 3 carbons and a -CH2- is replaced by -CO-.
m1+m7=1, m2+m8=0, m3+m9=0, m1 represents an integer of 1 or more.
Belfield is silent to X7 and the organic counteranion.
However, Kurata further discloses the actinic radiation-curable composition comprises the sulfonium salt compound represented by formula (1) (paragraph [0007-0008]) wherein X is any group selected from (A-1) in chemical formula 2 (paragraph [0009]) and R3 is any group selected from the following group B-1 in chemical formula 3 (paragraph [0009-0012]). In the group B-1, RA represents substituents and HAr represents substituted or unsubstituted heteroaryl group (paragraph [0013]). The HAr group may be substituted and examples of the substituents include those defined for RA (paragraph [0030]); RA is any one of a halogen atom, an alkyl group, an alkoxy group, an alkylthio group, and an alkylamine group (paragraph [0015]).
The genus of halogen contains 4 species for all practical matters – Iodine, Fluorine, Bromine, and Chlorine. Given the small size of the genus, a person having ordinary skill in the art would have been able to immediately envision each and every species encompassed by the genus “halogen”. The reference thus teaches that Ra may be Iodine or Fluorine.
The X groups comprise -O-, -S-, -CO-, -CH2 (corresponding to the claimed X7).
Regarding the organic ion, Kurata further discloses that in Chemical Formula 1, Z- represents a counterion that can be BF4-. PF6-, AsF6-, and complex ions such as sulfonate ions such as p-CH3C6H4SO3- and CF3SO3- (paragraph [0046]). When any of the compounds represented by General Formula 1 are used, the adhesiveness of the cured product to a substrate is improved (paragraph 0034]).
Chemical Formula 1 discloses that Z- can have several equivalent counterions including a fluorinated sulfonate anion. It would have been obvious for one of ordinary skill to have modified the counterion to be a sulfonic acid counterion through routine experimentation. The counteranions in General Formula 1 are disclosed as equivalents to one another, therefore one of ordinary skill would expect the modification of one counteranion for another, such as the sulfonic acid anion, to produce similar properties such as improving adhesiveness of the cured product to the substrate as suggested by Kurata (Claim 7).
The photoacid generators disclosed in Belfield and Kurata are similar and comprise substituted heterocyclic groups such as thiophene. Belfield and Kurata do not disclose all of the claimed limitations of the salt in one disclosed embodiment. Belfield discloses thiophene containing photoacid generators and Kurata discloses similar triphenylsulfonium salts having a bridging group and thiophen groups and the salts may have organic ions. It is prima facie obvious to combine the elements, such as cations and/or anions or functional groups, of two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third compositional embodiment to be used for the very same purpose…[T]he idea of combining them flows logically from their having been individually taught in the prior art. In re Kerkhoven, 205 USPQ 1069 1072. In the instant case, it would have been obvious to one of ordinary skill in the art to obtain a composition comprising the claimed salt arrive at the instant claims through routine experimentation.
Regarding Claim 2, the discussion of Claim 1 is relied upon as above. The structure disclosed in Fig. 4 of Belfield satisfies wherein A1 is *-X01-L01- and X01 is -CO- and L01 is a 2 carbon hydrocarbon group.
Regarding Claims 3 and 4, the discussion of Claim 2 is relied upon as above. Kurata further discloses other linking groups to connect the heterocyclic group among the structure of B-1 shown above (page 6 of the foreign patent, paragraph [0012]). Kurata further teaches salt 1-15 that satisfies where A1 is *-X01-L01-, X01 is -S- and L01 is a single bond. Kurata further teaches salt 1-127 that satisfies where A1 is *-L01-X01, X01 is -O- and L01 is a C1 alkanediyl where -CH2- is replaced by -CO-. Kurata further teaches salt 1-175 that satisfies where A1 is *-X01-L01-, X01 is -SO2- and L01 is a single bond. In all these cases, m2 and m3 are zero.
Regarding Claim 5, the discussion of Claim 1 is relied upon as above. Belfield further discloses in Fig. 4 the structure where m4 is 1, R4 is bromine.
Regarding Claim 6, the discussion of Claim 1 is relied upon as above. Kurata further discloses in Chemical Formula 1 that R1 and R2 are substituents chosen from any halogen, alkyl, alkoxy, alkylthio, and alkylamino groups, R4 may be a substituent chosen from halogen, hydroxyl, alkyl, and alkoxy groups, and further that R3 may be represented by HAr where HAr is a substituted or unsubstituted heteroaromatic group (paragraph [0007-0017]). The substituents for HAr include those substituents defined for R1 and R2 (paragraph [0030]). Further, Kurata discloses examples having particular substituents such as, in this non-exhaustive list, linear and branched alkyl (structures 1-2 and 1-4, 1-16, 1-18, 1-32, 1-36, 1-49, 1-61 paragraph [0048-0056]), cycloaliphatic (structure 1-214, paragraph [0071]), alkoxy (structure 1-146, paragraph [0064-], halogen (structures 1-80, 1-185, paragraph [0056, 0068]), and thioalkyl groups (structure 1-166, paragraph [0066]). Furthermore, Kurata discloses examples of substituents on the HAr groups to be alkyl (structure 1-4, 1-274), aromatic (structure 1-276), chlorine (structure 1-280), thioalkyl (structure 1-281) (paragraph [0079]).
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Claims 8, 10, and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Belfield (US Patent No. 8,192,590) in view of Kurata (JP 2008169231, reference citations from English translation) as applied to Claims 1 and 9 further in view of Li (US 2003/0008230).
Regarding Claims 7 and 8, the discussion of Claim 1 is relied upon as above. Kurata further discloses that in Chemical Formula 1, Z- represents a counterion that can be BF4-. PF6-, AsF6-, and complex ions such as sulfonate ions such as p-CH3C6H4SO3- and CF3SO3- (paragraph [0046]). When any of the compounds represented by General Formula 1 are used, the adhesiveness of the cured product to a substrate is improved (paragraph 0034]).
Kurata is silent to other sulfonic acid anions, sulfonylimide anions, or sulfonylmethide anions
However, Li teaches thiophene-containing photoacid generators comprising a counterion (abstract). The photoacid generators are sulfonium or iodonium cations with at least one thiophene or thiophene substituted with alkyl, alkoxy, or cycloalkyl (paragraph [0016-0017]). The anions disclosed may be perfluorinated alkyl sulfonate, perfluorinated aryl sulfonate, perfluorinated alkyl and aryl sulfonyl methide, perfluorinated alkyl and aryl sulfonyl imide and combinations thereof (paragraph [0017]). Example 1 demonstrates dimethyl-(2-thienyl)sulfonium perfluorobutanesulfonate salt (paragraph [0060]). Perfluorobutane sulfonate satisfies the anion of formula (I-A) where Q1 and Q2 are F, L1 is 2 carbon saturated hydrocarbon with all hydrogens replaced by F, and Y1 is a methyl group having 3 fluorine substituents. Additionally, thiophene PAGs absorb less light at 220 nm or less and may lead to chemically amplified photoresists exhibiting high resolution at lower wavelength (paragraph [0013]).
It would have been obvious for one of ordinary skill in the art to have modified the thiophene-containing sulfonium salts of Kurata with perfluorobutane sulfonate counterion disclosed by Li. Kurata discloses other fluorinated sulfonate counterions for the inventive photoacid generator compositions. One of ordinary skill in the art would expect substituting one sulfonate salt for another to produce a photoacid generator with substantially similar properties.
Regarding Claims 10 and 14, the discussion of Claim 1 is relied upon as above. Kurata further discloses the photoacid generator is used in negative-active photoresists with an oxirane or oxetane crosslinker (paragraph [0215-0216]). When any of the compounds represented by General Formula 1 are used, the adhesiveness of the cured product to a substrate is improved (paragraph 0034]).
Kurata is silent to a resist composition having a resin with an acid-labile group.
However, Li teaches thiophene-containing photoacid generators comprising a counterion and chemically amplified resist compositions containing a chemically amplified base polymer (abstract). Li teaches thiophene PAGs absorb less light at 220 nm or less and may lead to chemically amplified photoresists exhibiting high resolution at lower wavelength (paragraph [0013]). The base polymer of the resin may be positive or negative tone base polymer which may comprise conventional acid sensitive side chains that are bonded to the polymer backbone (paragraph [0023]). The photoacid generators are sulfonium or iodonium cations with at least one thiophene or thiophene substituted with alkyl, alkoxy, or cycloalkyl (paragraph [0016-0017]). Example 1 demonstrates dimethyl-(2-thienyl)sulfonium perfluorobutanesulfonate salt (paragraph [0060]); the photoacid generator is evaluated in a lithographic composition comprising the polymer resin Poly(1-methylcyclopentyl-5-norbornene-2-carboxylate-co-5-norbornene-2-spirolactone-co-5-norbornene-2-carboxylic acid) (paragraph [0064-0065]). The 1-methylcyclopentyl group is an acid-labile group.
Kurata and Li both demonstrate thiophene-containing photoacid generators used in negative-acting photoresist and chemically-amplified photoresists. Therefore, the thiophene-containing photoacid generators may be suitable for both negative-active and chemically-amplified photoresist compositions. Kurata and Li do not show a specific example of the claimed sulfonium salt in a resist composition comprising It would have been obvious for one of ordinary skill in the art to have combined the base polymer in Kurata with the acid-labile negative tone base polymer disclosed in Li. One of ordinary skill would have been motivated to make this modification since thiophene PAGs absorb less light at 220 nm or less and may lead to chemically amplified photoresist exhibiting high resolution at lower wavelength as suggested by Li.
Regarding Claim 14, the discussion of Claim 10 is relied upon as above. Li further discloses spin-coated the photoresist onto an antireflective material applied to silicon wafer, soft-based to produce a film, exposed to 193 nm radiation, post-exposure baked, and developed using aqueous TMAH developer (paragraph [0065]) (Claim 14).
Claim 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over Belfield (US Patent No. 8,192,590) in view of Kurata (JP 2008169231, reference citations from English translation) as applied to Claim 1 in view of Li (US 2003/0008230) as applied to Claim 10 and further in view of Ayothi (US 2013/0052585).
Regarding Claims 11-13, the discussion of Claim 10 is relied upon as above.
Li teaches thiophene-containing photoacid generators comprising a counterion and chemically amplified resist compositions containing a chemically amplified base polymer (abstract). The chemically amplified polymer comprises an acid-labile group (paragraph [0064-0065]).
Kurata and Li are silent to the acid-labile groups comprising structural units (a1-0, a1-1 or a1-2) and a structural unit of (a2-A); further Kurata and Li are silent to the resist composition further comprising a salt generating an acid having an acidity lower than that of an acid generated by the acid generator.
Ayothi discloses photodecomposable bases with dicarboxylate anion groups that show increased imaging performance (abstract). Ayothi discloses that photodecomposable bases are photoactive additives used in chemically amplified photoresist formulations to improve photoresist properties; furthermore, photodecomposable bases in chemically amplified photoresists offer improved performance, formulation stability, and delay stability over conventional base quenchers (paragraph [0003]). Photodecomposable bases are generally added to photoresist compositions to improve resolution, linearity bias, and to stabilize latent images (paragraph [0003]) (Claim 13). Ayothi notes that the photoresist polymers are generally well known in the art, and are insoluble in aqueous base solution but in the presence of an acid, the polymers are catalytically deprotected such that they become soluble in an aqueous base solution (paragraph 0036]). In Table 1, Ayothi discloses Resist A-J comprising the polymers PHS-MAdMA and PHS-EAdMA, a photoacid generator and a photodecomposable base (PHS = polyhydroxystyrene, M/EAdMA = (m)ethyl-adamantyl methacrylate, paragraph [0070]). Ayothi additionally discloses that depending on the photoresist the exposure may form positive or negative patterns (paragraph [0051]).
The PHS-MAdMA polymers of Ayothi satisfies Claim 11 formula (a1-1) where Ra4 is methyl, La1 is -O-, Ra6 is methyl or ethyl, m1 is 0 and Claim 12 formula (a2-A) where Ra50 is hydrogen, Aa50 is a single bond, and mb is 0 (Claim 11-12).
Li and Ayothi both disclose resist compositions comprising an acid-labile group. It would have been obvious for one of ordinary skill in the art to have to have substituted the resist composition in Li for the polyhydroxystyrene-ethyl-adamantyl methacrylate resist composition in Ayothi through routine experimentation. Both resist compositions perform the same function in a photoresist, namely to be insoluble in aqueous base solution until acted upon by an acid. One of ordinary skill would reasonably expect substituting the base resin polymer to create a working resist composition with similar properties.
Furthermore, it would have been obvious for one of ordinary skill in the art to have modified Kurata and Li with the photodecomposable of Ayothi. One of ordinary skill would have been motivated to make this modification to improve resolution, linearity bias, and to stabilize latent images as suggested by Ayothi.
Conclusion
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/A.P.T./Examiner, Art Unit 1737
/JONATHAN JOHNSON/Supervisory Patent Examiner, Art Unit 1734