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 § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 1, 3-7, 9, 11-12 and 14 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Chang (US 2021/0087210; IDS, 11/21/2024).
Chang is directed to an organometallic cluster photoresist of EUV lithography. Chang discloses a photoresist composition for forming a photoresist layer, where the photoresist composition includes an organometallic cluster compound of Formula I. (Para, 0055). Chang discloses the photoresist composition further includes a solvent which is capable of dissolving the organotin cluster compound of the present disclosure. (Para, 0056). Chang discloses examples of such solvents include, but are not limited to alcohols, aromatic hydrocarbons, and the like. (Para, 0056). These disclosures teach the limitation of claim 1, ‘ A semiconductor photoresist composition, comprising: an organometallic compound represented by Chemical Formula 1 and a solvent…’
Chang discloses the organometallic cluster compounds of the present disclosure are represented by formula I: [R1Sn(O)X]6 (I). (Para, 0038). Chang discloses that in some embodiments, R1 is an alkyl group or an optionally substituted aryl group. (Para, 0039). Chang discloses examples of alkyl groups include methyl, ethyl, or butyl. (Para, 0039). Chang also discloses in some embodiments, R1 is an n-butyl group. (Para, 0039). Chang discloses examples of aryl groups include phenyl, naphthyl, and anthracenyl and R1 is an alkyl substituted aryl group. (Para, 0039). Chang discloses X is a ligand having high radiation sensitivity in the radiation range and in some embodiments, X is a ligand having a high radiation sensitivity in the EUV range. (Para, 0040). Chang discloses in some embodiments, X is a conjugate base of an acid or X is a conjugate base of an organic carboxylic acid and is represented by formula (II): R2—Y—COO−(II). (Para, 0040). These disclosures teach the limitation of claim 1, ‘ A semiconductor photoresist composition, comprising: …Chemical Formula 1 [R1L1SnO(R2L2C(=O)O)]6…’
Chang discloses R2 is selected to provide high radiation sensitivity in the EUV range and to provide solubility control. (Para, 0041). Chang discloses in some embodiments, R2 is a substituted aryl group such as phenyl, naphthyl, and anthracenyl with example substituents including one or more halo groups such as one or more chloro groups or one or more nitro groups. (Para, 0041). Chang discloses In some embodiments, R2 is a chloro-substituted phenyl group and in some embodiments, R2 is an optionally substituted heteroaryl group. (Para 0041). Chang discloses examples of heteroaryl groups which includes a triazolyl group and a thienyl group and in some embodiments, the heteroaryl is substituted with an alkyl group containing from 1 to 20 carbon atoms or an aryl group optionally substituted with one or more alkyl, alkoxy, or halo groups. (Para, 0041). Chang discloses that Y is a linking group including an alkylene group containing from 1 to 6 carbons or a carbonyl group and gives examples of the alkylene groups to include methylene, ethylene, and propylene. (Para, 0042). Chang discloses in some embodiments, the linking group Y is a methylene group. These disclosures teach the limitation of claim 1, ‘ A semiconductor photoresist composition, comprising: …wherein, in Chemical Formula 1, R1 and R2 are each independently a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C31 arylalkyl group or a combination thereof, and L1 and L2 are each independently a single bond or a substituted or unsubstituted C1 to C10 alkylene group.’
Chang also illustrates the molecular structure of the organotin cluster compounds of the present disclosure determined by single-crystal X-ray diffraction studies. (Para, 0045). Chang discloses the organotin cluster compounds are a drum-like hexameric cluster. (Para, 0046). Chang explains, all the six tin atoms in an organotin cluster compound are chemically equivalent and each is hexacoordinated with three of the coordination sites occupied by bridging tri-coordinate oxygen atoms, two coordination sites occupied by carboxylate ligands with oxygen atoms forming the bridging, and one coordination site occupied by the functional group R1 covalently bonded to tin. (Para, 0046). Chang explains the organotin hexameric cluster is built around a drum shaped Sn6O6 central stannoxane core that is made up of two hexamer Sn3O3 rings. (Para, 0046). Chang explains these hexameric Sn3O3 rings exit in a puckered chair conformation and form the upper and lower lids of the drum polyhedron. (Para, 0046). Chang discloses the two Sn3O3 rings are connected further by six Sn—O bonds containing tri-coordinate O atoms and, thus, the side faces of the drum are characterized by six four-membered Sn2O2 rings. (Para, 0046). Chang discloses the two tin atoms in each of the six Sn2O2 rings are bridged by a carboxylate ligand to form a symmetrical bridge between two carboxylate ligands. (Para, 0046). These disclosures and the molecular structure illustrated in Para, 0045 teach the limitation of claim 3 as well as the limitations of claims 4-7.
Chang discloses the concentration of the organotin cluster compounds in the photoresist composition is selected to achieve desired physical properties of the solution. (Para, 0057). Chang discloses in some embodiments, the concentration of the organometallic cluster compound in the photoresist composition is in a range from about 0.5 wt. % to 10 wt. %. (Para, 0057). Chang discloses in some embodiments, the concentration of the organometallic cluster material in the photoresist composition is in a range from about 1 wt. % to 5 wt. % to provide good film forming property and patterning performance. (Para, 0057). These disclosures teach the limitation of claim 9.
Chang discloses the photoresist composition is prepared by mixing an organotin cluster compound in a solvent using appropriate mixing apparatus. (Para, 0058). Chang discloses the photoresist composition of the present disclosure is usable to form a photoresist coating in lithographic processes and to be used as an etch mask to create patterned features such as fins, metal lines with line widths less than about 32 nm. (Para, 0059). Chang illustrates the method 100 of forming a patterned structure on a substrate using the photoresist composition described above, in accordance with some embodiments. (Para, 0060; Figure. 1) Chang illustrates cross-sectional views of each step of the method 100 in Figures 2A through 2F. (Para, 0060).
As disclosed in Figure 1, the method 100 includes operation 102, in which a material layer 210 is deposited over a substrate 202, which is illustrated in Figure 2A of a semiconductor structure 200 after forming the material layer 210 over the substrate 202. (Para, 0062; Fig.2A). As illustrated in Figure 2A, the substrate 202 is provided and it can be any substrate 202 that is used in processes involving photoresists. (Para 0063; Fig.2A). Chang discloses the material layer 210 is formed over the substrate 202 and the material layer 210 is a conductive layer, a dielectric layer, a semiconductor layer or other material layers depending on the stage of the manufacturing processes. (Para, 0064; Fig.2A). These disclosures and illustrations teach the limitation of claim 11, ‘ A method of forming patterns, comprising: forming an etching-objective layer on a substrate…’
Chang discloses in Figure 1, the method 100 proceeds to operation 104, in which a photoresist layer 220 is deposited over the material layer 210. (Para, 0065; Fig.1). Chang also illustrates a cross-sectional view of the semiconductor structure 200 after depositing the photoresist layer 220 over the material layer 210. (Para, 0065; Fig.2B). These disclosures and illustrations teach the limitation of claim 11, ‘ A method of forming patterns, comprising: … coating the semiconductor photoresist composition of claim 1 on the etching-objective layer to form a photoresist layer…’
Chang discloses after depositing the photoresist layer 220, the photoresist layer 220 is subjected to a soft bake process that removes the solvent from the photoresist layer 220. (Para, 0068). Chang discloses the method 100 proceeds to operation 106, in which the photoresist layer 220 is exposed to a radiation beam 230. (Para, 0069; Fig.1). Chang illustrates a cross-sectional view of the semiconductor structure 200 after exposing the photoresist layer 220 to the radiation beam 230. (Para, 0069; Fig.2C). Chang discloses the photoresist layer 220 is exposed to the radiation beam 230 through a photomask 232 having a predefined pattern, which is placed above the photoresist layer 220 and includes blocking portions 234 that do not allow the radiation beam 230 to pass through so the pattern of the photomask 232 is transferred to the photoresist layer 220. (Para, 0070; Fig.2C). Chang explains the photoresist layer 220 is patterned and includes exposed portions 220a and unexposed portions 220b. Chang further explains the radiation causes cleavage of Sn—C bonds and crosslinking of the organo tin cluster compound in the exposed portions 220a of the photoresist layer 220, and results in a stable tin oxide (SnOx) with a high level of resistance to a developer subsequently used. (Para, 0070). These disclosures and illustrations teach the limitation of claim 11, ‘ A method of forming patterns, comprising: …patterning the photoresist layer to form a photoresist pattern…’
Chang discloses in some embodiments, the radiation is a deep ultraviolet (DUV) radiation such as KrF excimer laser (248 nm) or ArF excimer laser (193 nm), a EUV radiation (13.5 nm), an e-beam radiation, an x-ray radiation, an ion beam radiation, or other suitable radiations. (Para, 0071) This disclosure teaches the limitation of claim 12. Chang discloses the method 100 proceeds to operation 108, in which the photoresist layer 220 is developed to form a patterned photoresist layer 222 including a pattern, which is illustrated in a cross-sectional view of the semiconductor structure 200 after developing the photoresist layer 220 to form the patterned photoresist layer 222. (Para, 0074. Fig.2D). Chang explains in this step the photoresist layer 220 is developed to form a pattern in the photoresist layer 220 by applying a developer to the photoresist layer which is used to dissolve the unexposed portions 220b of the photoresist layer 220, while leaving the exposed portions 220a of the photoresist layer 220 intact. (Para, 0074; Fig.2D). Chang explains the unexposed portions 220b of the photoresist layer 220 are, thus, selectively removed from the semiconductor structure 200, and the exposed portions 220a of the photoresist layer 220 remain in the semiconductor structure 200. (Para, 0074; Fig.2D). Chang further explains, the remaining exposed portions 220a define a pattern in the patterned photoresist layer 222 and because of the small size of the organotin cluster compounds, the pattern in the patterned photoresist layer 222 is able to define features with pitches from about 24 nm to about 36 nm. (Para, 0074). These disclosures teach the limitation of claim 14.
Chang discloses the exposure of the photoresist layer 220 results in a stable tin oxide (SnOx) with a high level of resistance to the developer. (Para, 0078). Chang discloses the photoresist layer 220 of the present disclosure is able to be made thin without the risk of being removed during photoresist developing stage. (Para, 0078). Chang discloses the method 100 proceeds to operation 110, in which the material layer 210 is etched using the patterned photoresist layer 222 as an etch mask. (Para, 0079). Chang illustrates a cross-sectional view of the semiconductor structure 200 after etching the material layer 210 using the patterned photoresist layer 222 as an etch mask. (Para, 0079; Fig.2E). These disclosures teach the limitation of claim 11, ‘A method of forming patterns comprising: …and etching the etching-objective layer using the photoresist pattern as an etching mask.’
Therefore the recitations of claims 1, 3-7, 9, 11-12 and 14 are anticipated by the disclosures and illustrations of Chang.
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.
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.
Claim(s) 10 and 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chang.
As discussed in paragraph 3 above Chang is directed to an organometallic cluster photoresist of EUV lithography. Chang discloses that one type of photoresist used in EUV lithography is chemically amplified photoresists which use acid catalysis to increase sensitivity to exposure energy. (Para, 0036). Chang discloses a typical chemically amplified photoresist is formulated by dissolving an acid sensitive base polymer and a photoacid generator in a casting solution, where the base polymer in a chemically amplified positive photoresist typically has acid labile groups bonded to the polymer backbone. (Para, 0036). Chang explains, when such a photoresist is exposed to radiation, the PAG absorbs photons and produces an acid, which cause catalytic cleavage of the acid labile groups. (Para, 0036). These disclosures teach and/or suggest the limitation of claim 10. Chang discloses these resists can suffer from low etch resistance. (Para, 0036). Chang discloses to overcome this issue, typical EUV lithography forms a thin hard mask layer between the resist pattern and the SOC under layer, and the resist pattern is used as an etch mask for etching the thin hard mask layer. (Para, 0036). Chang discloses the hard mask layer is then used as an etch mask to pattern the thick SOC layer, thus providing a SOC pattern with high aspect ratio suitable for subsequent etching of the substrate. (Para, 0036). These disclosures in view of the disclosures of Chang as discussed above teach and/or suggest the limitation of claim 13.
The recitations of claims 10 and 13 would have been obvious to one of ordinary skill in the art at the time of filing of the present application by Applicant because the disclosures of Chang as discussed above provide one of ordinary skill in the art with a reasonable expectation of forming a precise photoresist patterning mask for semiconductor fabrication processes, where the addition of an organometallic compound to an EUV resist composition can improve the pattering process and etching resistance of the photoresist pattern used to pattern underlying layers in the device formation process.
Claim(s) 2 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chang as applied to claims 1, 3-7, 9, 11-12 and 14 in paragraph 3 above, and further in view of Cardineau (US 2019/0308998; IDS, 12/13/2023).
The disclosures of Chang as discussed in paragraph 4 above fail to teach the limitation of claim 8, ‘ The semiconductor photoresist composition of claim 1, wherein: the organometallic compound comprises any one of compounds of Group 1 or a combination thereof: Group 1 Chemical Formula 3-Chemical Formula 13 as illustrated in Claim 8. However, the disclosures of Chang further in view of the disclosures of Cardineau provide such teachings.
Cardineau is directed to alkyl tin clusters suitable for formation of radiation patternable coatings as well as alkyl ligands with tin atoms incorporated into the ligands. (Para, 0002). Cardineau discloses Extreme ultraviolet (EUV) lithography is a method to manufacture high-performance integrated circuits that contain high-density structures patterned on a nanometer scale where a photoresist is deposited on a substrate and exposed to a pattern of EUV light. (Para, 0003). Cardineau discloses exposed regions undergo radiolysis and a solubility change, which enable the EUV photo-pattern to be precisely transferred to the resist after solvent development and additional processing and the developed photoresist pattern is then passed on to the underlying substrate via an etch process. (Para, 0003). Cardineau also explains that in processing of semiconductor circuits and devices there is continued shrinkage of critical dimensions over each generation. (Para, 0004). Cardineau discloses that as these dimensions shrink, new materials and methods can be called upon to meet the demands of processing and patterning smaller and smaller features. (Para, 0004). Cardineau explains that metal-based radiation resists have been discovered that are especially suitable for providing good absorption of extreme ultraviolet (EUV) light and electron beam radiation, while simultaneously providing very high etch contrast. (Para, 0004).
Cardineau discloses alkyl tin clusters provide promising characteristics for radiation based patterning, and dodecamers of tin described herein are appropriately processible for tin EUV patterning. (Para, 0023). Cardineau discloses the tin dodecamers have oxo, hydroxo and formate ligands in which some of the ligands are bridging to stabilize the clusters and methods to substitute fluoride ions for formate and/or hydroxide ligands are also disclosed. (Para 0023). Cardineau discloses the tin dodecamer clusters are solid compounds that are soluble in suitable organic liquids. (Para, 0023). Cardineau explains that based on the higher tin content of these tin clusters, coatings formed from the tin compositions have high EUV absorption. (Para, 0023).
Cardineau discloses the dodecamer (QSn)12O14(OH)6(RCO2)2 (Q=alkyl or alkyl tin ligand and R=alkyl group or H) is an exemplary organotin cluster formulated as a metal oxide EUV photoresist. (Para, 0028). Cardineau discloses the carboxylate, e.g., formate, and optionally some or all of the hydroxide ligands can be substituted by fluoride ions and the Q ligand generally can have a quaternary carbon atom or tin atom. (Pra, 0028). The disclosures of Chang further in view of these disclosures teach and/or suggest the limitation of claim 2. Cardineau discloses for the alkyl groups with a quaternary carbon atom, these alkyl groups have been found generally to form desirable patterning coatings, and these ligands generally can have from 5 to 17 carbon atoms. (Para, 0028). Cardineau discloses the alkyl tin ligands have a tin atom replacing a quaternary carbon of an analogous alkyl group, and can comprise from four to 16 carbon atoms. (Para, 0028). Cardineau discloses the ligands having quaternary carbons that are replaced with Sn still provide a C-Sn bond of the dodecamer in the formula above to form a Sn-(CH2)n-Sn moiety, where n is 1 to 4. (Para, 0028). Cardineau explains the substitution of a quaternary carbon can be advantageous for EUV lithography, as Sn has an EUV absorption cross section greater than C (see Table 1). (Para, 0028). Cardineau also illustrates an example dodecamer for use in a EUV photoresist in Figure 3, which is a drawing of the crystal structure of (t-BuSn)12O14(OH)6(HCOO)2.4n-C3H5OH. The disclosures of Chang further in view of these disclosures and the illustrations of Figure 3 of Cardineau teach and/or suggest the limitation of claim 8.
It would have been obvious to one of ordinary skill in the art at the time of filing of the present application by Applicant to modify the disclosures of Chang further in view of Cardineau because both are directed to analogous EUV photoresist composition comprising metal-based or organometallic compounds to improve etching resistance and the photoresist pattern forming process and Cardineau discloses tin dodecamer compounds which one of ordinary skill in the art would have a reasonable expectation successfully incorporating into the photoresist composition of Chang to form photoresist compositions with high tin content and EUV adsorption for forming a precise resist pattern and etching mask for smecindoutor device fabrication.
Conclusion
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/CALEEN O SULLIVAN/Primary Examiner, Art Unit 2899