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 .
Drawings
The drawings are objected to because the included figure does not have an identifying label (e.g. “Figure 1” or “Fig. 1”). Per 37 C.F.R. 1.84 (c), identifying indicia should be provided for drawings and/or figures. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
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) 1-17 and 19-20 are rejected under 35 U.S.C. 103 as being unpatentable over JP 5368512 B2 (hereby referred to as JP ‘512) in view of US 20220348698 A1 (hereby referred to as Omatsu) and US 20150185615 A1 (hereby referred to as Park).
Regarding Claims 1-14, JP ‘512 discloses a resist protective film composition containing a copolymer. The protective film is an overlayer film (JP ‘512, paragraph 0005 of the English translation), which is analogous to the topcoat recited by the instant application. The overlayer film composition comprises the copolymer and a solvent (JP ‘512, paragraph 0090 of the English translation). The copolymer may contain a repeat unit comprising the functional group represented by chemical formula 2 (JP ‘512, paragraph 0013 of the English translation and page 4 of the original publication). For instance, the polymer may comprise the repeat unit according to chemical formula 3-a (JP ‘512, paragraph 0016 of the English translation), the structure of which is reproduced below.
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In formula 3-a, R12, R23, and R24 represent hydrogen, halogen, alkyl, or halogenated alkyl; R3 and R4 are hydrogen, alkyl, or halogenated alkyl; R5 is a hydrocarbon group; and n is an integer of 1 to 6 (JP ‘512, paragraph 0018 of the English translation). Specific examples of such a repeat unit are shown in chemical formulae 4-a, 5-a, 6-a, and 7-a (JP ‘512, paragraph 0019 of the English translation). Chemical formulae 4-a and 5-a are shown on page 6 of JP ‘512 and are reproduced below.
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Chemical formulae 4-a and 5-a are identical to the first two structural units of instant claim 8, wherein R1 is a methyl group. Both structures represent the “first structural unit” recited by instant claims 1-7. The inclusion of such a repeating unit allows for the surface of the topcoat to be improved and reduces defects (JP ‘512, paragraph 0084 of the English translation). This allows the topcoat film to sufficiently protect the underlying resist layer (JP ‘512, paragraph 0089 of the English translation).
However, JP ‘512 is silent in regards to additional repeat units. Omatsu teaches a compound and polymer formed from the same. Omatsu further teaches a composition for forming a film, wherein the composition may be used for upper layer (i.e. topcoat) film formation (Omatsu, paragraph 0619). The composition comprises a polymer and may further contain a solvent (Omatsu, paragraph 0621). The polymer comprises a constitutional unit derived from a particular compound (Omatsu, paragraph 0568). The particular compound comprises one or more halogens and an unsaturated double bond (Omatsu, paragraph 0306). The halogen is preferably iodine (I) (Omatsu, paragraph 0307). Particular examples of the compound are provided in paragraph 0364 of Omatsu (refer to pages 19-21 of Omatsu). Some such compounds are reproduced below.
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The above compounds, when polymerized to produce a copolymer, yield recurring units according to the second structural unit recited by instant claims 1 and 9-12. Thus, Omatsu teaches the second structural unit according to instant claims 1 and 9-12.
However, JP ‘512 and Omatsu are silent in regards to a third repeat unit. Park teaches photolithographic methods. The method involves coating a photoresist overcoat composition over a photoresist layer (Park, paragraph 0010). The overcoat composition includes a quenching polymer (Park, paragraph 0015), which may be a copolymer (Park, paragraph 0017), and is characterized by a repeating unit having a basic moiety (Park, paragraph 0018). Including a repeat unit having a basic moiety allows for neutralization of acid in the regions of an underlying photoresist layer intended to be unexposed (Park, paragraph 0018). Park teaches particularly useful monomers to produce a repeat unit having a basic moiety (Park, paragraph 0021). Some preferred monomers are shown on page 4 of Park and are reproduced below.
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Several of the above monomers, when polymerized, yield repeat units recited by instant claim 14. Furthermore, several of the explicitly shown (but not preferred) monomers (refer to pages 2-3 of Park) also yield repeat units according to instant claim 14. Thus, Park teaches the third structural unit recited by instant claims 1 and 13-14.
JP ‘512, Omatsu, and Park are analogous art because each reference pertains to polymers used as topcoat layers. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to produce a copolymer comprising at least the first structural unit disclosed by JP ‘512, the second structural unit taught by Omatsu, and the third structural unit taught by Park because each of the structural units provides an advantageous benefit for a topcoat composition. For instance, the first structural unit disclosed by JP ‘512 provides low affinity to water and hydrophobicity (JP ‘512, paragraph 0086 of the English translation), which protects the underlying resist layer from environmental factors. The second structural unit taught by Omatsu provides increased sensitivity to an exposure light source (Omatsu, paragraphs 0364 and 0554), which is beneficial for patterning the underlying resist layer because a topcoat layer is an additional medium for which the exposure light must pass through to reach the photosensitive resist layer, and thus the improved sensitivity allows for improved pattern accuracy when using a topcoat layer. The third structural unit taught by Park provides a basic moiety that neutralizes the acid in the underlying photoresist layer intended to be unexposed (Park, paragraph 0018 and 0022), which improves the pattern accuracy by preventing unexposed regions from becoming developer soluble/insoluble (depending on type of resist) and thus mitigating irregularities in the pattern (Park, paragraph 0018). Therefore, It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to produce a copolymer combining each type of structural unit to obtain a topcoat layer providing each of the beneficial effects attributed to each respective structural unit. Refer to MPEP 2143 I. A.
Regarding Claim 15, JP ‘512 discloses that the fluorine-containing monomer (first structural unit) is present in the copolymer in an amount of 40 mol% to 99 mol% (JP ‘512, paragraph 0085 of the English translation). Such a content yields a copolymer with low affinity for water and appropriate hydrophobicity (JP ‘512, paragraph 0086 of the English translation). Omatsu teaches that the iodine-containing monomer (second structural unit) is present in the copolymer in an amount of 5 mol% or more and preferably 30 mol% or less (Omatsu, paragraph 0578). Such a content provides sufficient sensitivity to the exposure light and allows for thin line patterns to be formed (Omatsu, paragraph 0568). Park teaches that the basic moiety-containing monomer (third structural unit) is present in the copolymer in an amount that is preferably 2 to 15 mol% based on the total weight of the polymer (Park, paragraph 0022). Park further teaches that the content of the basic moiety-containing unit will dependent on the content of the photoacid generator in the photoresist layer and type of lithography process used (dry or immersion) (Park, paragraph 0022). When the content of the basic moiety-containing unit is within the aforementioned range, acid-induced deprotection reaction in the unexposed (“dark”) regions of the underlying resist layer is sufficiently suppressed or eliminated (Park, paragraph 0022), thereby improving pattern accuracy. Thus, the copolymer according to instant claim 15 is obvious in view of the disclosures of JP ‘512, Omatsu, and Park.
Regarding Claim 16, JP ‘512 discloses that the copolymer has a weight average molecular weight of 1,000 to 500,000, and more preferably has a weight average molecular weight of 2,000 to 100,000 (JP ‘512, paragraph 0087 of the English translation). Per MPEP 2144.05 I., when the prior art discloses a range that overlaps with the claimed range, a prima facie case of obviousness exists.
Regarding Claim 17, JP ‘512 discloses that the overlayer film composition comprises the copolymer and a solvent, such that the copolymer is present in an amount of preferably 0.1 to 10% by weight relative to the total overlayer film composition (JP ‘512, paragraph 0091 of the English translation).
Regarding Claim 19, JP ‘512 discloses that the overlayer film composition includes the copolymer and a solvent (JP ‘512, paragraph 0090 of the English translation). The solvent may be an ether solvent (JP ‘512, paragraph 0092 of the English translation), such as di-n-butyl ether, di-n-pentyl ether, or di-n-hexyl ether (JP ‘512, paragraph 0096 of the English translation). Each of these solvents can be represented by Chemical Formula 4.
Regarding Claim 20, JP ‘512 discloses a pattern forming method comprising forming a photoresist film on a substrate, forming an overlayer film comprising the protective copolymer composition, and exposing and developing the layers (JP ‘512, paragraph 0098 of the English translation). In the examples, the overlayer protective film solution is baked (JP ‘512, paragraph 0142 of the English translation), which corresponds to the heating step recited by instant claim 20.
Claim(s) 18 is rejected under 35 U.S.C. 103 as being unpatentable over JP 5368512 B2 (hereby referred to as JP ‘512) in view of US 20220348698 A1 (hereby referred to as Omatsu) and US 20150185615 A1 (hereby referred to as Park) as applied to claim 1 above, and further in view of US 20040265706 A1 (hereby referred to as Montgomery).
Regarding Claim 18, the combination of JP ‘512, Omatsu, and Park renders obvious the topcoat composition according to instant claim 1, as explained above. The proposed combination of said prior art yields a copolymer comprising structural units recited by instant claims 8, 12, and 14. However, none of the aforementioned cited art discloses or suggests a pH of the obtained topcoat composition.
Montgomery teaches methods of extending the stability of a photoresist. In Montgomery’s invention, a substrate is provided with a chemically amplified resist (CAR) layer and a protective topcoat overlying the CAR (Montgomery, paragraph 0017). Montgomery teaches that the protective topcoat should have a pH between 5 and 8 (Montgomery, paragraph 0044). When the pH is within this range, the storage life of the resist coated substrate is increased (Montgomery, paragraph 0044).
JP ‘512, Omatsu, Park, and Montgomery are analogous art because each reference pertains to topcoat protective layers over a resist layer. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to modify the topcoat composition obtained by combining the teachings of JP ‘512, Omatsu, and Park such that the pH of the composition is between 5 and 8, as taught by Montgomery, because the storage stability of a substrate coated with a resist is increased when the topcoat layer has a pH in this range (Montgomery, paragraph 0044).
Conclusion
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/JAYSON D COSGROVE/Examiner, Art Unit 1737
/JONATHAN JOHNSON/Supervisory Patent Examiner, Art Unit 1734
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