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 .
Response to Amendment
Claims 1-12 are pending. claims 1-6, 10-12 are rejected under prior arts. Claims 7-9 are objected to as being dependent upon a rejected base.
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 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) 1-3, 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yamada et al. (US 7,696,099 B2) and further in view of Heinecke (US 3,940,506).
With respect to claim 1, Yamada teaches a method comprising: providing a substrate in which a recess 120 is formed and having exposed silicon oxide film 102 (fig. 5; col. 5, lines 51-55)
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; etching the silicon oxide film 102 with a mixture of CHF3, and O2 (col. 6, line 65-col. 7, line 5; fig. 6)
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Unlike claimed invention, Yamada doesn’t teach the etching gas comprises of a hydrogen-containing gas different from the trifluoromethane gas. Heinecke teaches a plasma etching method for silica or silicon dioxide and silicon where hydrogen gas is added to control etching rate between the silica and the silicon (col. 2 ,lines 25-35). It would have been obvious for one skilled in the art before the effective filing date of the invention to add hydrogen gas to the etching gas because Heinecke teaches that adding hydrogen would enable one skilled in the art to control relative etching rate between silicon dioxide and the silica with an etching rate ratio such as 2:1 to 1:5 depending upon a number of parameters (col. 2, lines 25-35) and also reduce etching rate of the photoresist (col. 3, lines 1-5), which in this case, it would help to reduce the etching of the photoresist 104 used by Yamada so that the silicon oxide film 102 and the substrate can be etched with expected results.
With respect to claims 2 and 3, figure 5 from Yamada above shows the supplied gas mixture including the CH3 gas, O2, and hydrogen-containing gas would have to be set so that it is able to penetrate through the top layers or according a depth of the recess above the silicon oxide film 102 in order to reach and excessively etch the silicon oxide 102 and to provide rounded corners as shown in fig. 6 (col. 6, line 65-col. 7, line 5) or a targeted etching shape
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.
With respect to claim 11, the silicon oxide film 102 is exposed and etched in the recess as shown in fig 5 and 6 above.
Claim(s) 4-6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yamada and Heinecke as applied to claims 1-3 above, and further in view of Zhang et al. (CN 113517296A).
With respect to claims 4-6, Yamada doesn’t teach forming a silicon oxide film in the recess after etching the silicon film 102. However, he teaches the process is for forming shallow trench isolation where “a shallow trench is formed to bury an insulation film” (col. 1, line 10-15). Zhang further teaches a method for forming shallow trench isolation wherein he describes forming a silicon oxide layer 406 in the recess after etching the pad silicon oxide 401 (pages 8-9; fig. 5)
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. It would have been obvious for one skilled in the art before the effective filing date of the invention to form a silicon oxide film in the recess or trench in light of Zhang in order to form shallow trench isolation, which is desired by Yamada, with expected results.
Claim(s) 10, 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yamada et al. (US 7,696,099 B2) and Heinecke (US 3,940,506), as applied to claim 1 above, and further in view of Sung et al. (US 2021/0066047A1).
With respect to claim 10, Yamada describes an etching method including the steps of claim 10, see rejection of claim 1 above. Unlike claimed invention, he doesn’t teach using an apparatus having a vacuum chamber, a gas supply that supplies a gas to the vacuum chamber and a controller is configured to the etching steps. Sung teaches an etching apparatus having chamber interior 125 with a gas exhaust port 516 to evacuating as gas from the chamber or claimed a vacuum chamber (para 39, 51); a gas supply 150 (para 33, 58); “a controller configured to control the gas delivery system, the inductive element, and the bias source to implement a spacer open process. The spacer open process may include operations” (para 6, 54; fig. 4).
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One skilled in the art before the effective filing date of the invention would find it obvious to use an apparatus such as one taught by Sung because using known element without changes in its functions, in this case using the apparatus for the same purpose of providing a plasma for Yamada’s etching process, would enable one skilled in the art to provide a plasma for the etching process with expected results.
With respect to claim 12. Figure 4 from Sung shows each gas is supplied from a separate source. Therefore, it would have been obvious and within the knowledge of one skilled in the art to provide the gases from their respective sources in order to provide the gases for the silicon oxide etching with expected results.
Allowable Subject Matter
Claims 7-9 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claims 7-9 are allowed over the applied prior art because neither Yamada nor Zhang, further teaches repeating the etching step or claimed step b) of the silicon oxide film with trifluoromethane gas, an oxygen-containing gas, and a hydrogen-containing gas and the step of forming the silicon oxide in the recess or claimed step c).
Response to Arguments
Applicant’s arguments with respect to amended claim(s) 1-6, 10 have been considered but are moot because the new ground of rejections based on Yamada, Heinecke, and Sung as set forth 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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/DUY VU N DEO/Primary Examiner, Art Unit 1713
6/26/2026
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