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 § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-9 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Chung et al (KR 10-2021-0041499) in view of Lopez Villanueva et al (US 11,970,647 B2).
As to claims 1 and 9, Chung discloses a silicon etching solution (abstract, see English machine translation) comprising:
a quaternary ammonium hydroxide (pH adjuster, lines 240, 268);
an oxidizing agent (e.g., hydrogen peroxide, line 134);
water (purified water, lines 170-175); and
an acid-group containing compound, heptanoic acid (line 247, also a pH adjuster, which may be used in a combination of two or more, lines 274-75), which has a carboxy group, pKa in the cited range.
As to amended claim 1, Chung discloses that the content of the oxidizing agent is 5 to 50 mass%, 1.5-15 mol/L (line 155), which as pointed out by applicant in his arguments (filed July 25, 2025, at page 5) for hydrogen peroxide corresponds to a range greater than the newly cited range of 0.01-0.30 mol/L, 0.034-1.02 mass%.
Lopez Villanueva teaches an etching solution similar to Chung, in that they both etch SiGe (abstract). Lopez Villanueva teaches that the etching solution comprises:
a quaternary ammonium fluoride (col.5, lines 23-24; Chung, line 113);
an oxidizing agent (e.g., hydrogen peroxide, col.3, line 57);
water (abstract), and
an acid-group containing compound (inorganic acid, e.g., phosphoric acid, col.5, line 65; or an organic acid, such as a C1 to C10 carboxylic acid, col.6, lines 1-2).
While there are differences between the disclosures of Lopez Villanueva and Chung, they are sufficiently similar that one of ordinary skill in the art would look to Lopez Villanueva for guidance about the concentration of oxidizing agent. Lopez Villanueva teaches that the oxidizing agent content may comprise 0.01 to 3.0 mol/L (col.4, lines 58-61). This is a wide range, that overlaps with both the range cited by Chung of 5 to 50 mass%, or 1.5-15 mol/L, and the cited range. The oxidizing agent serves the same purpose in both Lopez Villanueva and Chung, that of oxidizing. It is expected to serve the same purpose at the lower claimed concentration. Both Lopez Villanueva and Chung do not give particular criticality to the oxidizing concentration, nor does the instant invention. Accordingly, it would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include the cited concentration of oxidizing agent in the composition of Chung because Lopez Villanueva teaches that such ranges are useful for silicon etching compositions. Further, the cited content is expected to give the predictable property of oxidizing when the etching solution is used for etching.
As to claims 2-3, see the rejection of claim 1, heptanoic acid has one carboxy group, pKa, HLB values in the cited range.
As to claim 4, Chung that the acid group-containing compound may be present at an amount of 0.01% to 10% by mass (lines 276-77), which is expected to overlap with the cited range.
As to claims 5-6, Chung discloses heptanoic acid and hydrogen peroxide, see the rejection of claim 1.
As to claims 7-8, Chung discloses to bring the silicon etching solution into contact with a silicon (lines 345-46), which inherently includes etching a silicon plane (because silicon has planes) and to manufacture a silicon device (lines 365-69).
As to claim 12, Chung discloses phosphoric acid (line 255). Still further, Lopez Villanueva also discloses that various C1 to C10 carboxylic acids may be included (ol.6, lines 1-2), which also render obvious the cited butanoic, hexanoic and octanoic acids because they are C4, C6 and C8 carboxylic acids. It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include butanoic, hexanoic and octanoic acids in the composition of Chung because Lopez Villanueva teaches that they are useful for adjusting the pH, which is expected to be useful to adjust the pH of the solution to a desired pH level to obtain desired results.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Chung et al (KR 10-2021-0041499) in view of Lopez Villanueva et al (US 11,970,647 B2), as applied to claim 1 and further in view of Nakagawa et al (US 2013/0026134 A1).
As to claim 10, Chung fails to disclose that the oxidizing agent comprises meta-chloroperoxybenzoic acid. Nakagawa teaches that in etching solutions (abstract) that the oxidizing agent may comprise agents such as hydrogen peroxide or meta-chloroperoxybenzoic acid [0056]. It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include meta-chloroperoxybenzoic acid in the oxidizing agent of the modified etching solution of Chung because Nakagawa teaches that it is a useful alternative oxidizing agent for hydrogen peroxide, and such is expected to give the predictable result of providing oxidizing properties to the etching solution.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Chung et al (KR 10-2021-0041499) in view of Lopez Villanueva et al (US 11,970,647 B2), as applied to claim 1 and further in view of Korzenski et al (US 2009/0192065 A1) or Oshita et al (US 11,787,894 B2).
As to claim 11, Chung fails to disclose that the oxidizing agent comprises an N-oxyl compound. Korzenski teaches that in chemical solutions, the oxidizing agent may comprise agents such as hydrogen peroxide or 2,2,6,6-tetramethylpiperidinoxyl (TEMPO) [0078], which is an N-oxyl compound. Oshita also teaches that in chemical solutions, that oxidizing agents may comprise hydrogen peroxide or TEMPO (col.12, lines 60-63). It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include an n-oxyl compound in the oxidizing agent of the modified etching solution of Chung because Korzenski and Oshita teach that it is a useful alternative oxidizing agent for hydrogen peroxide, and such is expected to give the predictable result of providing oxidizing properties to the etching solution.
Response to Amendment
Applicant’s arguments, see page 5, filed July 25, 2025, with respect to the claim rejection over Chung et al have been fully considered and are persuasive. The 35 USC 102 rejection of the claims over Chung has been withdrawn.
The 35 USC 103 rejection over Liu is withdrawn. Upon further consideration, Liu teaches that benzoquinones are preferable to hydrogen peroxide (page 10, Example 2), and fails to suggest to include hydrogen peroxide or another oxidizing agent elsewhere in Liu’s disclosure. Accordingly, there is no motivation to use hydrogen peroxide or another oxidizing agent in the etching solution of Liu. Thus, the rejection over Liu is withdrawn.
The claims are now rejected under 35 USC 103 over Chung et al (KR 10-2021-0041499) in view of Lopez Villanueva et al (US 11,970,647 B2), and for claims 10-11, further in view of Nakagawa et al (US 2013/0026134 A1), Korzenski et al (US 2009/0192065 A1) or Oshita et al (US 11,787,894 B2). Lopez Villanueva is newly cited to show the motivation to vary the concentration of the oxidizing agent in the solution of Chung. Nakagawa is newly cited to show the obviousness of including meta-chloroperoxybenzoic acid as an oxidizing agent in the solution of Chung. Korzenski and Oshita are newly cited to show the obviousness of including an oxyl compound as an oxidizing agent in the solution of Chung.
Response to Arguments
Applicant’s arguments with respect to the claims have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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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/ANITA K ALANKO/Patent Examiner, Art Unit 1713
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