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
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 are rejected under 35 U.S.C. 103 as being unpatentable over US 20220299877 A1 (hereby referred to as Weidman).
Regarding Claims 1-2 and 17, Weidman teaches positive tone development of EUV resist films. Weidman teaches a method wherein a precursor is deposited as a film on a substrate, wherein the precursor optionally includes a counter-reactant (Weidman, paragraph 0079 and Fig. 3). The deposited film may be post-application treated to provide a hardened resist film (Weidman, paragraph 0080). The produced photoresist is then exposed to EUV radiation to produce a pattern (Weidman, paragraph 0081) and developed into a photoresist pattern (Weidman, paragraph 0082-0083). The precursor may have a structure of MaRbLc, which is defined as Formula (II) of Weidman (Weidman, paragraph 0120). In Formula (II), M represents a metal having a high EUV absorption cross-section; each R is, independently, a halogen, an optionally substituted alkyl, an optionally substituted aryl, and optionally substituted amino, and optionally substituted alkoxy, or L; and each L is, independently, a ligand, an anionic ligand, a neutral ligand, a multidentate ligand, ion, or other moiety that is reactive with a counter-reactant (Weidman, paragraph 0121-0123). The values of a, b, and c are all greater than or equal to 1 (Weidman, paragraph 0124). In particular, the metal (M) may be bismuth (Bi) (Weidman, paragraph 0129). The optionally substituted amino group (R) is -NR1R2, wherein each R1 and R2 is, independently, a hydrogen atom or alkyl (Weidman, paragraph 0131). In some embodiments, at least one of R or L is optionally substituted alkyl, such as methyl, ethyl, isopropyl, or t-butyl (Weidman, paragraph 0133). Weidman provides examples of suitable precursors wherein bismuth is utilized, such as BiR3, wherein each R is independently halogen, C1-12 alkyl, di-C1-12 alkylamino (e.g. -NR1R2), and the like (Weidman, paragraph 0141). The counter-reactant included with the precursor preferably have the ability to replace the reactive moieties of the precursor, so as to link at least two metal atoms via chemical bonding (Weidman, paragraph 0157).
Weidman does not explicitly disclose a precursor having the formula of R’Bi(NR2)2 as recited by instant claim 1. However, the broader disclosure of Weidman renders obvious a photoresist precursor having the aforementioned formula. Specifically, paragraph 0141 of Weidman teaches a precursor having a formula of BiR3, wherein each R is, independently, chosen from the group of halogens, optionally substituted C1-12 alkyl, mono-C1-12 alkylamino (e.g., —NR1H), di-C1-12 alkylamino (e.g., —NR1R2), optionally substituted aryl, optionally substituted bis(trialkylsilyl)amino (e.g., —N(SiR1R2R3)2), or a diketonate (e.g., —OC(R4)-Ak-(R5)CO—) and wherein each R1 to R3 is, independently, alkyl and each R4 to R5 is, independently, hydrogen or alkyl. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to arrive at a photoresist precursor having the structure of R’Bi(NR2)2 according to instant claim 1 in view of the disclosure of Weidman because Weidman provides a general precursor structure (BiR3) and teaches that each R group may be independently chosen to be an alkyl or dialkylamino group (see Weidman, paragraph 0141). The teachings of Weidman for the alkyl structures include groups recited by instant claims 1-2, such a methyl, ethyl, isopropyl, and t-butyl (Weidman, paragraph 0133 and 0135). Per at least MPEP 2143 I. E. (“Obvious to try” rationale), one having ordinary skill in the art would find at least one of the structures encapsulated by the formula R’Bi(NR2)2 according to instant claim 1 prima facie obvious by choosing appropriate groups for the BiR3 structure taught by Weidman. Furthermore, substituting one of (NMe2) groups in the Bi(NMe2)3 precursor explicitly taught by Weidman (Weidman, paragraph 0141) with an appropriate alkyl group, as suggested by Weidman (Weidman, paragraph 0133 and 0141) would also yield the claimed precursor structure. Thus, MPEP 2143 I. B. (Simple substitution of one known element for another to obtain predictable results) also applies to establish a prima facie case of obviousness in view of Weidman.
The Examiner further notes that Weidman does not explicitly disclose that the obtained photoresist has a structure of BixOyCz, as recited by instant claim 1. However, Fig. 1A of Weidman depicts a schematic of a gas phase hydrolysis, condensation, and polymerization mechanism for depositing a resist film (Weidman, paragraph 0063). The non-limiting precursor (1) is reacted with water (i.e. a co-reagent) to yield a photoresist having an organometallic oxide structure (Weidman, paragraph 0063-0064). Per paragraph 0030 of the instant application’s specification, water may be a suitable co-reagent, and thus it would be expected by one having ordinary skill in the art that the obvious variant of the bismuth-based precursor obtained from the broader disclosure of Weidman, when exposed to water as a co-reagent (as suggested by Weidman, paragraph 0063-0064 and 0157), would yield a photoresist having a formula of BixOyCz as recited by instant claim 1. As stated above, the resist film is formed on a substrate (Weidman, paragraph 0078-0079). Therefore, the apparatus according to instant claim 17 is also obtained.
Regarding Claims 3-4, Weidman teaches that the counter-reactant (which is analogous to the claimed co-reagent) may be oxygen (O2-), ozone (O3), water, peroxides, oxygen plasma, water plasma, alcohols, dihydroxy alcohols, polyhydroxy alcohols, fluorinated alcohols and glycols, formic acid, and other sources of hydroxyl moieties, as well as combinations thereof (Weidman, paragraph 0157).
Regarding Claim 5, Weidman teaches that the metal precursor and the one or more counter-reactant(s) are deposited using techniques such as chemical vapor deposition (CVD), atomic layer deposition (ALD), or spin-coating deposition (Weidman, 0167-0169).
Regarding Claims 6 and 18, Weidman teaches that the deposited film has a thickness of 0.5 nm to 100 nm (Weidman, paragraph 0166). The film has a thickness that is sufficient to absorb most of the EUV light under EUV patterning conditions, and thus it may be preferable that the film has a thickness between 10 nm and 20 nm (Weidman, paragraph 0166).
Regarding Claims 7-8 and 20, Weidman teaches that the resist film is patterned by an EUV exposure, wherein the patterning can include the use of a mask having EUV transparent regions and EUV opaque regions (Weidman, paragraph 0075-0076 and 0113). The patterned film is then developed to remove the EUV exposed areas to yield a patterned positive-tone resist (Weidman, paragraph 0077 and 0083). Following development, the patterned film may be baked (Weidman, paragraph 0084). Whilst the disclosure of Weidman teaches primarily positive-tone resist patterns, Weidman further teaches that the EUV photoresist material can be effectively patterned to give a negative-tone image (Weidman, paragraph 0110 and 0061). Thus, one having ordinary skill in the art would find it obvious to try patterning the photoresist of Weidman to be a negative-type photoresist, wherein the development in an appropriate developing solution would remove unexposed regions of the patterned resist layer rather than the exposed regions of the patterned resist layer (Weidman, paragraph 0061, 0110, and 0105). See MPEP 2143 I. E.
Regarding Claims 9-10, Weidman teaches positive tone development of EUV resist films. Weidman teaches a method wherein a precursor is deposited as a film on a substrate, wherein the precursor optionally includes a counter-reactant (Weidman, paragraph 0079 and Fig. 3). The deposited film may be post-application treated to provide a hardened resist film (Weidman, paragraph 0080). The produced photoresist is then exposed to EUV radiation to produce a pattern (Weidman, paragraph 0081) and developed into a photoresist pattern (Weidman, paragraph 0082-0083). The precursor may have a structure of MaRbLc, which is defined as Formula (II) of Weidman (Weidman, paragraph 0120). In Formula (II), M represents a metal having a high EUV absorption cross-section; each R is, independently, a halogen, an optionally substituted alkyl, an optionally substituted aryl, and optionally substituted amino, and optionally substituted alkoxy, or L; and each L is, independently, a ligand, an anionic ligand, a neutral ligand, a multidentate ligand, ion, or other moiety that is reactive with a counter-reactant (Weidman, paragraph 0121-0123). The values of a, b, and c are all greater than or equal to 1 (Weidman, paragraph 0124). In particular, the metal (M) may be bismuth (Bi) (Weidman, paragraph 0129). The optionally substituted amino group (R) is -NR1R2, wherein each R1 and R2 is, independently, a hydrogen atom or alkyl (Weidman, paragraph 0131). In some embodiments, at least one of R or L is optionally substituted alkyl, such as methyl, ethyl, isopropyl, or t-butyl (Weidman, paragraph 0133). Weidman provides examples of suitable precursors wherein bismuth is utilized, such as BiR3, wherein each R is independently halogen, C1-12 alkyl, di-C1-12 alkylamino (e.g. -NR1R2), and the like (Weidman, paragraph 0141). The counter-reactant included with the precursor preferably have the ability to replace the reactive moieties of the precursor, so as to link at least two metal atoms via chemical bonding (Weidman, paragraph 0157).
Weidman does not explicitly disclose a precursor having the formula of R’2BiNR2 as recited by instant claim 9. However, the broader disclosure of Weidman renders obvious a photoresist precursor having the aforementioned formula. Specifically, paragraph 0141 of Weidman teaches a precursor having a formula of BiR3, wherein each R is, independently, chosen from the group of halogens, optionally substituted C1-12 alkyl, mono-C1-12 alkylamino (e.g., —NR1H), di-C1-12 alkylamino (e.g., —NR1R2), optionally substituted aryl, optionally substituted bis(trialkylsilyl)amino (e.g., —N(SiR1R2R3)2), or a diketonate (e.g., —OC(R4)-Ak-(R5)CO—) and wherein each R1 to R3 is, independently, alkyl and each R4 to R5 is, independently, hydrogen or alkyl. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to arrive at a photoresist precursor having the structure of R’2BiNR2 according to instant claim 9 in view of the disclosure of Weidman because Weidman provides a general precursor structure (BiR3) and teaches that each R group may be independently chosen to be an alkyl or dialkylamino group (see Weidman, paragraph 0141). The teachings of Weidman for the alkyl structures include groups recited by instant claims 9-10, such a methyl, ethyl, isopropyl, and t-butyl (Weidman, paragraph 0133 and 0135). Per at least MPEP 2143 I. E. (“Obvious to try” rationale), one having ordinary skill in the art would find at least one of the structures encapsulated by the formula R’2BiNR2 according to instant claim 9 prima facie obvious by choosing appropriate groups for the BiR3 structure taught by Weidman. Furthermore, substituting one of Me groups in the BiMe3 precursor explicitly taught by Weidman (Weidman, paragraph 0141) with an appropriate dialkylamino group, as suggested by Weidman (Weidman, paragraph 0135 and 0141) would also yield the claimed precursor structure. Thus, MPEP 2143 I. B. (Simple substitution of one known element for another to obtain predictable results) also applies to establish a prima facie case of obviousness in view of Weidman.
The Examiner further notes that Weidman does not explicitly disclose that the obtained photoresist has a structure of BixOyCz, as recited by instant claim 9. However, Fig. 1A of Weidman depicts a schematic of a gas phase hydrolysis, condensation, and polymerization mechanism for depositing a resist film (Weidman, paragraph 0063). The non-limiting precursor (1) is reacted with water (i.e. a co-reagent) to yield a photoresist having an organometallic oxide structure (Weidman, paragraph 0063-0064). Per paragraph 0030 of the instant application’s specification, water may be a suitable co-reagent, and thus it would be expected by one having ordinary skill in the art that the obvious variant of the bismuth-based precursor obtained from the broader disclosure of Weidman, when exposed to water as a co-reagent (as suggested by Weidman, paragraph 0063-0064 and 0157), would yield a photoresist having a formula of BixOyCz as recited by instant claim 9.
Regarding Claims 11-12, Weidman teaches that the counter-reactant (which is analogous to the claimed co-reagent) may be oxygen (O2-), ozone (O3), water, peroxides, oxygen plasma, water plasma, alcohols, dihydroxy alcohols, polyhydroxy alcohols, fluorinated alcohols and glycols, formic acid, and other sources of hydroxyl moieties, as well as combinations thereof (Weidman, paragraph 0157).
Regarding Claim 13, Weidman teaches that the metal precursor and the one or more counter-reactant(s) are deposited using techniques such as chemical vapor deposition (CVD), atomic layer deposition (ALD), or spin-coating deposition (Weidman, 0167-0169).
Regarding Claim 14, Weidman teaches that the deposited film has a thickness of 0.5 nm to 100 nm (Weidman, paragraph 0166). The film has a thickness that is sufficient to absorb most of the EUV light under EUV patterning conditions, and thus it may be preferable that the film has a thickness between 10 nm and 20 nm (Weidman, paragraph 0166).
Regarding Claims 15-16, Weidman teaches that the resist film is patterned by an EUV exposure, wherein the patterning can include the use of a mask having EUV transparent regions and EUV opaque regions (Weidman, paragraph 0075-0076 and 0113). The patterned film is then developed to remove the EUV exposed areas to yield a patterned positive-tone resist (Weidman, paragraph 0077 and 0083). Following development, the patterned film may be baked (Weidman, paragraph 0084). Whilst the disclosure of Weidman teaches primarily positive-tone resist patterns, Weidman further teaches that the EUV photoresist material can be effectively patterned to give a negative-tone image (Weidman, paragraph 0110 and 0061). Thus, one having ordinary skill in the art would find it obvious to try patterning the photoresist of Weidman to be a negative-type photoresist, wherein the development in an appropriate developing solution would remove unexposed regions of the patterned resist layer rather than the exposed regions of the patterned resist layer (Weidman, paragraph 0061, 0110, and 0105). See MPEP 2143 I. E.
Regarding Claim 19, Weidman teaches that the substrate on which the resist film is formed may be any material construct suitable for lithographic processing, and in some embodiments the substrate may be a semiconductor substrate, such as a silicon wafer (Weidman, paragraph 0181).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US 20200124970 A1 (hereby referred to as Kocsis) teaches patterned organometallic photoresists and methods of patterning. Specifically, Kocsis teaches that organometallic-based photoresist compositions can function as either negative or positive resists (Kocsis, paragraph 0018), and that such a property has been used to sequentially develop the resist to improve pattern uniformity of the lithographic pattern (Kocsis, paragraph 0018). This prior art further supports the disclosure of Weidman, which demonstrates that the organometallic photoresist described by Weidman, whilst primary developed as a positive-type photoresist, can also act as a negative-type photoresist.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAYSON D COSGROVE whose telephone number is (571)272-2153. The examiner can normally be reached Monday-Friday 10:00-18:00.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Mark Huff can be reached at (571)272-1385. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JAYSON D COSGROVE/Examiner, Art Unit 1737
/JONATHAN JOHNSON/Supervisory Patent Examiner, Art Unit 1734