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 .
Specification
The amendment to the specification overcome the objection to the drawing. The objection to the drawing is withdrawn.
Claim Rejections - 35 USC § 112
The rejection of claim 5 under 35 USC 112(b) is withdrawn because claim 5 has been cancelled.
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 1-4, 6, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Lin (US 2018/0138034) in view of Chang ‘493 (US 2016/0093493) or Chang ‘944 (US Patent 9,012,132, IDS 03/31/2022).
Regarding Claim 1-3, Lin teaches methods of forming a semiconductor device (abstract). The method includes forming an underlayer over a substrate, forming a middle layer over the underlayer, and forming a patterned upperlayer over the middle layer (paragraph [0134]). In some embodiments, the middle layer includes photoacid generator, thermal-acid generator, photobase generator, or thermal-base generator and a quencher, and in some embodiments further comprises a crosslinker unit (paragraph [0031]). The middle layer is thermally baked for cross-linking and may or may not comprise a solvent (paragraph [0033]). The middle layer may include hydrophilic additives such as poly(γ-caprolactone), poly(ethylene oxide), poly(propylene oxide), random poly(ethylene oxide-propylene oxide), alternating poly(ethylene oxide-propylene oxide), block poly(ethylene oxide-propylene oxide), cyclodextrin, any other suitable hydrophilic additives in a wt% range of 1 to 40 wt% (paragraph [0035-0036]) (Claims 2-3). The range of incorporating hydrophilic additives overlaps the claimed range. The upper layer is exposed to a radiation beam and developed to form a patterned upper layer (paragraph [0049-0050]). During the etching process, the hydrophilic additives are removed from the middle layer to form pores in the middle layer (paragraph [0062]) and the middle layer containing pores has better wet strippability due to the greater surface area and may be efficiently removed (paragraph [0064]).
Lin further discloses a second method to form pores in the middle layer comprising baking the middle layer, which forms pores prior to the etching process (paragraph [0091]). As shown in FIG. 3C, the middle layer 106 is baked at a second temperature to remove the second solvent 130 to form multiple first pores 120B in the middle layer 106 (paragraph [0117]).
Lin is silent to wherein the sacrificial additives are floated onto a top surface of the middle layer.
Chang ‘493 teaches method of forming a middle layer comprising a floating additive polymer at an upper surface of the middle layer including a fluorine-containing material (abstract). The fluorine-containing material generates a thin, inner barrier layer in the middle layer that minimized possible interactions between the photoresist layer and the middle layer (paragraph [0021]). The floating additive polymers includes a fluorine containing material and chemically bound to a photoacid generator and a polarity switchable group with an acid labile group (paragraph [0043]). Chang ‘493 teaches that the top portion has a greater concentration (i.e, percentage) than a bottom portion [0021].
Alternatively, Chang ‘944 teaches a method of forming a BARC on a substrate (abstract). The single layer BARC includes at least two kinds of polymers, and may include a polymer that has a fluorine functional unit such as CF3, C2F5, or C3F7 to impart a polymer floating ability (Col 5, Ln 14-24). Furthermore the BARC may be a single layer that separates after coating into an upper and lower portion due to movement of chemical components (Col 5, Ln 59 to Col 6 Ln 3). It is clear that the top portion has a greater concentration (i.e, percentage) of the methacrylate than a bottom portion.
It would have been obvious for one of ordinary skill in the art to have modified the hydrophilic additives of Lin to be floating additive polymers as demonstrated by Chang ‘493. One of ordinary skill would have been motivated to make this modification to minimize the possible interactions between the photoresist layer and the middle layer as suggested by Chang ‘493.
It would have been obvious for one of ordinary skill in the art to have modified the hydrophilic additives of Lin to be with fluoroalkyl groups of Chang ‘944. One of ordinary skill would have been motivated to make this modification to achieve a floating ability on the hydrophilic polymers as suggested by Chang ‘944.
Regarding Claim 4, the discussion of Claim 1 is relied upon as above. Chang ‘493 further teaches that the structures in Fig 6B may be further modified to float by including a fluorine atom or an alkyl fluorine such as CF3, C2F5, C3F7. Chang ‘944 further teaches that the fluoroalkyl groups to impart a floating ability are CF3, C2F5, or C3F7 (Col 5, Ln 14-24).
Regarding Claim 6, the discussion of Claim 1 is relied upon as above. Lin further teaches inn FIG. 2C, the middle layer 106 is baked at a second temperature to remove the second solvent 130 to form multiple pores 120B in the middle layer 106, where in some embodiments, the second temperature is in a range from about 180° C to about 320° C (paragraph [0090]). This range overlaps the claimed range of the heating process.
Regarding claim 21, Chang ‘493, Fig. 4 shows that the bottom portion of the middle layer may be free of the additives.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Lin (US 2018/0138034) in view of Chang (US 2016/0093493) as applied to Claim 1 and further in view of Waldfried (US 20060024976).
Regarding Claim 4, the discussion of Claim 1 is relied upon as above. Lin further teaches the middle layer include hydrophilic additives including various polymers (paragraph [0035]). Lin further discloses a second method to form pores in the middle layer comprising baking the middle layer, forming pores prior to etching (paragraph [0091]).
Lin is silent to the sacrificial additives comprising a perfluoroalkyl side chain and where the sacrificial additives comprises CxFy wherein x is 1 to 10.
However, Waldfried teaches process for forming porous low k dielectric materials containing a porogen (abstract). Suitable matrix precursors include silicon polymers, thermosetting compositions and others (paragraph [0041]). Waldfried discloses that the porogen material may be activated by exposure to ultraviolet radiation to release a cleavable organic group such as Waldfried discloses that the silicon porogen material may be materials susceptible to removal upon exposure to ultraviolet radiation such as carboxylates with alkyl, fluoroalkyl, perfluoroalkyl, cycloalkyl, aryl, fluoroaryl, vinyl, allyl, or other side chains (paragraph [0045]). The concentration of pores in the porous matrix is sufficiently high to lower the dielectric constant but sufficient low to allow the matrix to withstand the process steps in manufacturing an electronic device, the concentration is between 5 and 70 volume percent (paragraph [0039]). While Waldfried does not specify the fluoroalkyl groups or perfluoroalkyl groups, Waldfried notes that the particular porogen employed is a matter of design choice depending on factors such as pore size (paragraph [0045]). The perfluoroalkyl group would comprise the chemical formula CxFy where x is 1 to 10. At the simplest case, a perfluoroalkyl group may be CF4 which satisfies the claimed limitation.
Lin and Waldfried both disclose methods of incorporating additives in order to promote pore formation in a layer for lithographic process. The pore formation step of Lin utilizes a baking step to remove hydrophilic additives while Waldfried uses a reactive exposure to ultraviolet radiation to release a cleavable organic group. It would have been obvious for one of ordinary skill in the art to have modified the pore formation step of Lin with the pore formation step in Waldfried and to have modified the hydrophilic additive to include some portion of perfluoroalkyl side chains through routine experimentation. One of ordinary skill would reasonably expect such the modification of Lin to produce a similar middle layer containing pores.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Lin (US 2018/0138034) in view of Chang (US 2016/0093493) or Chang ‘944 (US Patent 9,012,132, IDS 03/31/2022) as applied to Claim 1 in view of Baldwin (US 2014/0227538).
Regarding Claim 7, the discussion of Claim 1 is relied upon as above. Lin further teaches etching means (paragraph [0063]) and heating means (paragraph [0090]) may be used to remove the hydrophilic additives.
Lin and Chang are silent to removing the sacrificial additives by using a solvent.
However, Baldwin teaches anti-reflective coating materials comprising a porogen (abstract). Baldwin discloses that the decomposed porogen is removable from or can volatilize or diffuse through a partially or fully cross-linked matrix to create pores in a fully-cured matrix (paragraph [0085]). In another embodiment, when the porogen does not decompose, it may be dissolved out of the matrix leaving behind a pore (paragraph [0085]). Examples of porogens include various hydrophilic polymers (paragraph [0087-0088]). Examiner notes that the act of dissolving in Baldwin would necessitate the sacrificial additive being removed by using a solvent.
Lin and Baldwin both teach methods of forming pores in underlayer compositions by different means. It would have been obvious for one of ordinary skill in the art to have modified the pore-formation means of Lin with Baldwin’s method of dissolving the porogen to form a pore through routine experimentation. One of ordinary skill would reasonably expect this substitution to form a porous layer by removing the hydrophilic additive.
Claims 8-10 and 13-14 are rejected under 35 U.S.C. 103 as being unpatentable over Ho et al. (US 2004/0069745) in view of Kwinten (US 2009/0311623).
Regarding Claim 8, Ho teaches a method comprising:
forming a middle layer (31) over a substrate (30), wherein the middle layer has a porous top surface with a plurality of holes (sidelobes 38) ([0034], Fig. 2b);
depositing a photoresist layer (40) over the porous top surface of the middle layer, wherein a hole concentration at the porous top surface of the middle layer is greater than a hole concentration in the middle layer prior to depositing the photoresist layer (See Fig. 2d, the holes get narrower away from the top surface so the concentration of holes at the top is greater than throughout the bulk of the layer), the photoresist layer comprises quenchers [0037], and portions of the photoresist layer are disposed in the holes of the porous top surface of the middle layer ([0036] and Fig. 2d);
exposing the photoresist layer to a radiation beam ([0038], Fig. 2d); and
developing the photoresist layer after exposing the photoresist layer ([0039], Fig. 2e).
Ho does not teach that the quenchers are decomposable nor performing a heating process which modifies the distribution of the quenchers. However, Kwinten teaches using photodecomposable quenchers [0089] that diffuse during heating pretreatment [0091] in order to reduce sidelobes.
Therefore, it would have been obvious at the time of filing the instant invention to have used decomposable quenchers as the particular quenchers of Ho, and to have caused them to diffuse during a heating pretreatment in order to reduced the sidelobes.
Claims 9-10: Ho teaches that the size and distribution of the sidelobes may vary [0034]. It does not state pose any limits on the depth or pattern of sidelobes that can be treated. Therefore, it would have been obvious at the time of filing the instant invention to have used the method of Ho and Kwinten to treat and size or areal coverage of holes with a reasonable expectation of success.
Claim 13: Ho teaches that the photoresist layer may include carbon-containing compounds such as poly(vinylacetal) [0037].
Claim 14: Kwinten teaches that the pretreatment temperature may be 70-80 degrees C. (Table I on p. 7).
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Ho et al. (US 2004/0069745) in view of Kwinten (US 2009/0311623), as applied to claim 8 above and further in view of Hansen (US 2006/0134529).
Ho and Kwinten are discussed above. Neither specifies the depth of the sidelobes, but Ho implies that its method works regardless of the size of the sidelobes [0034]. Hansen indicates that typical sidelobe depths may include those less than 150 nm [0052]. Therefore, it would have been obvious at the time of filing the instant invention to have used the method of Ho and Kwinten with sidelobes with depths less than 150 nm with a reasonable expectation of success given that Ho can generally treats sidelobes and Hansen teaches that sidelobes with depths of less than 150 nm are known defects.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Ho et al. (US 2004/0069745) in view of Kwinten (US 2009/0311623), as applied to claim 8 above and further in view of Lee (US 6,235,448).
Ho and Kwinten are discussed above. They do not teach that Ho’s photoresist middle layer (31) is free of photoacid generators. However, Lee teaches that the addition of photoacid generators to photoresist is optional (col. 2, lines 1-5; col. 5, lines 46-55) and that they may be omitted to avoid problems with storage stability or gas production (col. 1, lines 41-54). Therefore, it would have been obvious at the time of filing of the instant invention to have omitted photoacid generators from the middle layer of Ho to have avoided problems with storage stability or gas production.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Ho et al. (US 2004/0069745) in view of Kwinten (US 2009/0311623), as applied to claim 8 above and further in view of Chiang (US 5,262,500).
Ho and Kwinten are discussed above. Ho teaches a diazonaphthoquinone photoresist [0050] for making integrated circuits [0002]. They do not teach that Ho’s photoresist middle layer (31) is silicon-containing. However, Chiang teaches silicon-containing polymers mixed with diazonaphthoquinone for photolithography to make integrated circuits (col. 1, lines 6-13) for the purpose of better adhesion to the underlying substrate without use of an adhesion promoter (col. 2, lines 7-19). Therefore, it would have been obvious at the time of filing of the instant invention to have included a silicon-containing polymer in Ho’s photoresist for better adhesion to the underlying substrate.
Claims 15-18 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Lin (US 2018/0138034) in view of Baldwin (US 2014/0227538) in view of (Chang ‘493 (US 2016/0093493) or Chang ‘944 (US Patent 9,012,132, IDS 03/31/2022).)
Regarding Claim 15 and 20, Lin teaches methods of forming a semiconductor device (abstract). The method includes forming an underlayer over a substrate (Claim 20), forming a middle layer over the underlayer, and forming a patterned upperlayer over the middle layer (paragraph [0134]). In some embodiments, the middle layer includes photoacid generator, thermal-acid generator, photobase generator, or thermal-base generator and a quencher, and in some embodiments further comprises a crosslinker unit (paragraph [0031]). The middle layer is thermally baked for cross-linking and may or may not comprise a solvent (paragraph [0033]). The middle layer may include hydrophilic additives such as poly(γ-caprolactone), poly(ethylene oxide), poly(propylene oxide), random poly(ethylene oxide-propylene oxide), alternating poly(ethylene oxide-propylene oxide), block poly(ethylene oxide-propylene oxide), cyclodextrin, any other suitable hydrophilic additives in a wt% range of 1 to 40 wt% (paragraph [0035-0036]). The upper photoresist layer is exposed to a radiation beam and developed to form a patterned upper layer (paragraph [0049-0050]). During the etching process, the hydrophilic additives are removed from the middle layer to form pores in the middle layer (paragraph [0062]) and the middle layer containing pores has better wet strippability due to the greater surface area and may be efficiently removed (paragraph [0064]).
Lin further discloses a second method to form pores in the middle layer comprising baking the middle layer, which forms pores prior to the etching process (paragraph [0091]). As shown in FIG. 3C, the middle layer 106 is baked at a second temperature to remove the second solvent 130 to form multiple first pores 120B in the middle layer 106 and in Fig. 3D the upper layer 108 is applied over the porous middle layer (paragraph [0117]).
Lin is silent to after performing the first heating process, providing a solvent to the sacrificial additives to remove the sacrificial additives.
However, Baldwin teaches anti-reflective coating materials comprising a porogen (abstract). Baldwin discloses that the decomposed porogen is removable from or can volatilize or diffuse through a partially or fully cross-linked matrix to create pores in a fully-cured matrix (paragraph [0085]). In another embodiment, when the porogen does not decompose, it may be dissolved out of the matrix leaving behind a pore (paragraph [0085]). Examples of porogens include various hydrophilic polymers (paragraph [0087-0088]). Examiner notes that the act of dissolving in Baldwin would necessitate the sacrificial additive being removed by using a solvent.
Lin and Baldwin both teach methods of forming pores in underlayer compositions by different means. It would have been obvious for one of ordinary skill in the art to have modified the pore-formation means of Lin with Baldwin’s method of dissolving the porogen with a solvent to form a pore through routine experimentation. One of ordinary skill would reasonably expect substitution the method of removing hydrophilic additives in Lin with the dissolution method of Baldwin to form a porous middle layer.
Lin is silent do not teach that the sacrificial additives are floated onto a top surface of the middle layer. However, this feature is rendered obvious by Chang ‘493 or Chang ‘132 for the reasons given above for claim 1.
Regarding Claim 16, the discussion of Claim 15 is relied upon as above. Lin further discloses in some embodiments, the middle layer includes photoacid generator, thermal-acid generator, photobase generator, or thermal-base generator and a quencher, and in some embodiments further comprises a crosslinker unit (paragraph [0031]). Furthermore, the photoresist layer includes a photo-acid generator (PAG) distributed in the photoresist layer (paragraph [0041]).
Lin is silent to the photoresist containing a greater concentration of photoacid generators than the middle layer.
However, Lin demonstrates suitable the middle layer may contain suitable alternatives to a photoacid generator to perform the same function, such as a thermal-acid generator, photobase generator, or thermal-base generator and a quencher as described above. Thus, based on the disclosure of Lin, suitable embodiments of the middle layer and photoresist layer fully encompass middle layers without photoacid generator and a photoresist layer with a photoacid generator such that the photoresist layer has a greater concentration of photo-acid generator than the middle layer. It would have been obvious for one of ordinary skill in the art to have modified the middle layer to not contain a photoacid generator due to the alternative compounds disclosed in Lin. One of ordinary skill would reasonably expect this substitution to form a suitable middle layer containing pores as disclosed in Lin.
Claim 17: Chang ‘493 teaches method of forming a middle layer comprising a floating additive polymer at an upper surface of the middle layer including a fluorine-containing material (abstract). The fluorine-containing material generates a thin, inner barrier layer in the middle layer that minimized possible interactions between the photoresist layer and the middle layer (paragraph [0221]). The floating additive polymers includes a fluorine containing material and chemically bound to a photoacid generator and a polarity switchable group with an acid labile group (paragraph [0043]).
Alternatively, Chang ‘944 teaches a method of forming a BARC on a substrate (abstract). The single layer BARC includes at least two kinds of polymers, and may include a polymer that has a fluorine functional unit such as CF3, C2F5, or C3F7 to impart a polymer floating ability (Col 5, Ln 14-24). Furthermore the BARC may be a single layer that separates after coating into an upper and lower portion due to movement of chemical components (Col 5, Ln 59 to Col 6 Ln 3).
It would have been obvious for one of ordinary skill in the art to have modified the hydrophilic additives of Lin to be floating additive polymers as demonstrated by Chang ‘493. One of ordinary skill would have been motivated to make this modification to minimize the possible interactions between the photoresist layer and the middle layer as suggested by Chang ‘493.
It would have been obvious for one of ordinary skill in the art to have modified the hydrophilic additives of Lin to be with fluoroalkyl groups of Chang ‘944. One of ordinary skill would have been motivated to make this modification to achieve a floating ability on the hydrophilic polymers as suggested by Chang ‘944.
Regarding Claim 18, the discussion of Claim 15 is relied upon as above. Lin further teaches in some embodiments, the middle layer 106 includes a solvent such as propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether (PGEE), propylene Glycol Methyl Ether (PGME), butanol, isobutanol, isopentanol, isopropyl alcohol, any other suitable solvent (paragraph [0033]). Further, the middle layer may contain a hydrophilic additive
Baldwin further discloses that when the porogen does not decompose, it may be dissolved out of the matrix leaving behind a pore (paragraph [0085]).
Lin and Baldwin are silent to explicit solvents that may be used to remove the hydrophilic additives.
However, Baldwin teaches the porogen or additive may be dissolved out of the matrix leaving behind a pore and Lin teaches solvents for the middle layer that are capable of dissolving the hydrophilic additives. It would have been obvious for one of ordinary skill in the art to have modified the method of removing hydrophilic additives in Lin with a solvent, and to have used the solvents disclosed in Lin for this purpose through routine experimentation. One of ordinary skill would reasonably expect that the solvents capable of dissolving hydrophilic additives in the middle layer would further be capable of removing hydrophilic additives in the crosslinked film.
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over Lin (US 2018/0138034) in view of Baldwin (US 2014/0227538) and (Chang ‘493 (US 2016/0093493) or Chang ‘944 (US Patent 9,012,132, IDS 03/31/2022)) as applied to Claim 15 and further in view of Waldfried (US 20060024976) or
Regarding Claim 17, the discussion of Claim 1 is relied upon as above. Lin further teaches the middle layer include hydrophilic additives including various polymers (paragraph [0035]). Lin further discloses a second method to form pores in the middle layer comprising baking the middle layer, forming pores prior to etching (paragraph [0091]).
Lin and Baldwin are silent to the sacrificial additives comprising a perfluoroalkyl side chain and where the sacrificial additives comprises CxFy wherein x is 1 to 10.
However, Waldfried teaches process for forming porous low k dielectric materials containing a porogen (abstract). Suitable matrix precursors include silicon polymers, thermosetting compositions and others (paragraph [0041]). Waldfried discloses that the porogen material may be activated by exposure to ultraviolet radiation to release a cleavable organic group such as Waldfried discloses that the silicon porogen material may be materials susceptible to removal upon exposure to ultraviolet radiation such as carboxylates with alkyl, fluoroalkyl, perfluoroalkyl, cycloalkyl, aryl, fluoroaryl, vinyl, allyl, or other side chains (paragraph [0045]). The concentration of pores in the porous matrix is sufficiently high to lower the dielectric constant but sufficient low to allow the matrix to withstand the process steps in manufacturing an electronic device, the concentration is between 5 and 70 volume percent (paragraph [0039]).
Lin, Baldwin and Waldfried all disclose methods of incorporating additives in order to promote pore formation in a layer for lithographic process. The pore formation step of Lin utilizes a baking step to remove hydrophilic additives while Waldfried uses a reactive exposure to ultraviolet radiation to release a cleavable organic group. It would have been obvious for one of ordinary skill in the art to have modified the pore formation step of Lin with the pore formation step in Waldfried and to have modified the hydrophilic additive to include some portion of perfluoroalkyl side chains through routine experimentation. One of ordinary skill would reasonably expect such the modification of Lin to produce a similar middle layer containing pores.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Lin (US 2018/0138034) in view of Baldwin (US 2014/0227538) and (Chang ‘493 (US 2016/0093493) or Chang ‘944 (US Patent 9,012,132, IDS 03/31/2022)) as applied to Claim 15 further in view of Fukui (US 2017/0146901) and Nishikori (US 2019/0391488).
Regarding Claim 19, the discussion of Claim 15 is relied upon as above. Lin further teaches the middle layer may comprise a photo-base generator (paragraph [0031]).
Lin and Baldwin are silent to a second heating process to the photoresist such that a concentration of the PDQs in the photoresist layer decreases downwardly.
However, Fukui teaches forming a resist film having a photoacid generator low-concentration region formed at a part where the resist film is in contact with a thin film (abstract). In this process, a resist is formed over thin film 11 and then baked, as a result the low-concentration region 12a is formed, in which the concentration of the photoacid generator is gradually decreased downward (paragraph [0133]). The low concentration region can be formed irrespective of the thin film 11 (paragraph [0134]). The resist pattern that was formed showed an LER of 4.8 nm, and resolution was improved by forming the resist film in a multilayer structure and by decreasing the PAG concentration of the thin film side resist layer than the surface side (paragraph [0172]).
Nishikori teaches radiation-sensitive composition containing a polymer having an acid labile group, an acid generator, compound (C) and a solvent (paragraph [0022]). Compound (C) is a carboxylate with appropriate basicity while maintaining stability as a carboxylate anion to shorten the diffusion length from the acid generator, leading to improved LWR performance (paragraph [0024]) higher resolution and superior rectangularity (paragraph [0328]). Nishikori forms resist patterns by applying an antireflective coating to a silicon wafer, depositing the radiation-sensitive resin over the antireflective coating, exposing with ArF excimer laser Immersion Scanner, and subjected to a post-exposure bake at 90 C for 60 sec, thereafter developing the photoresist layer (paragraph [0302]). The Examiner asserts that the compound C acts as the claimed photodecomposable base due to its effect to shorten the diffusion length from the acid generator leading to improved LWR.
Lin, Baldwin, Fukui, and Nishokori all teach methods related to lithography middle layers and photoresist layers. It would have been obvious for one of ordinary skill in the art to have modified the photoresist layer of Lin with the photoresist composition of Nishikori comprising a photoacid generator and a carboxylate salt and the baking step of Nishikori through routine experimentation. One of ordinary skill would expect this modification to produce a working photoresist with a baking step.
The modification of Nishikori with Lin would produce a photoresist comprising a photoacid generator and photodecomposable base. While Fukui is silent to explicitly showing photodecomposable bases creating a low concentration region after a baking step, it would be obvious for one of ordinary skill in the art to expect a photoacid generator and a photodecomposable base, both of which are photoactive onium salts, to behave similarly and both form low concentration regions after a baking step. Thus, the combination of Nishikori with Lin in view of the low-concentration regions of Fukui demonstrate a photoresist layer wherein after performing the second heating process, a concentration of the PDQs in the photoresist layer decreases downwardly.
Response to Arguments
Applicant's arguments filed 10/8/25 have been fully considered but they are not persuasive.
Applicant argues that the amendments to claims 1 and 15 overcome the rejections. The argument is unconvincing because both Chang ‘493 and Chang ‘944 teach that the additives float to the top and therefore have a greater percentage at the top of the layer than at the bottom.
Applicant argues that the amendments to claim 8 overcome the rejections based on Lin in view of Nishikori. The argument is convincing, btu upon further search and consideration, new rejections are applied based on Ho in view of Kwentin, 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.
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/MICHAEL B CLEVELAND/Supervisory Patent Examiner, Art Unit 1712
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