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 .
Election/Restrictions
Claims 1-10 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 3/17/25.
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) 11-13, 15-17, 20-23 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 2023/0307290 to Abel (relying on PCT filing date 6/28/21 for priority) in view of van de Ven (Advantages of Dual Frequency PECVD for Deposition of ILD and Passivation Films).
Claim 11:
Abel teaches a method for forming air gaps in semiconductor substrates [0002-0003]. The method (Fig. 1c) includes providing a substrate having a trench structure defined by upper, lower, and sidewall surfaces (Fig. 2a, step 131), uniformly providing an inhibiting layer onto the structure comprising a halogen [0040-0041] (step 135), removing part of the inhibiting layer located at the top of the structure (step 137), and performing ALD/CVD to selectively deposit material at the top of the structure (step 139) while the inhibiting material remains on the sidewall to prevent material formation (Fig. 2e). See also Fig. 2a-2f. These steps are repeated until the trench is capped (step 141).
The main embodiment here is to deposit silicon oxide as the material layer [0069]. In both ALD and CVD, the process for depositing the silicon oxide includes supplying a silicon precursor and supplying an ionized oxygen (plasma) after supplying the silicon precursor [0036; 0067; 0078]. Abel states this includes continuously flowing reactant gases with intermittent plasma ignitions [0068].
Although Abel does teach both a high and low frequency RF power source that are controlled independently of each other [0091], Abel does not explicitly teach they are used together.
However, van de Ven teaches the combination of high and low frequency (i.e., dual frequency) provides a solution to plasma processing including a stable discharge combined with ion bombardment/implantation as well as improved control over the process (pg. 196).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to practice the method of Abel and use the high and low frequency RF power sources together. Van de Ven establishes the combined use of high and low frequency has the above identified advantages in plasma assisted deposition.
Claim 12:
The inhibitor can be removed during material deposition [0032; 0042; 0046].
Claim 13:
The inhibiting is the same across the different embodiments [0045]. The inhibiting is an inhibition species that has been ionized into a plasma [0030]. The inhibiting can be repeated as necessary (Fig. 3a-3d).
Claim 15:
The inhibitor can be removed in a separate step by using a plasma to directionally impinge only at the top of the structure (i.e., perpendicular to the substrate) [0031] and is repeated as necessary (Fig. 1a, step 111). The plasma is a reactant [0042] and purging between steps in an ALD, or even CVD, process is inherent.
Claim 16:
The reactants are an oxygen precursor plasma or a nitrogen precursor plasma [0067].
Claim 17:
The material layer is formed from a silicon precursor [0069-0072].
Claim 20:
The power sources are operated at any suitable power to form a plasma having a desired ion energy in order to provide the desired surface reactions described above [0091].
Claims 21, 23:
Van de Ven states the mechanisms behind the low frequency RF in plasma generation, but ultimately find independent control to allow optimization and process flexibility. In this respect, the low-frequency RF power, including zero (i.e., not supplied), would have been obvious to one of ordinary skill in the art through routine optimization of a result effective variable identified in the prior art.
Claim 22:
The process of Fig. 1c is a 1:1 process.
Claim(s) 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 2023/0307290 to Abel in view of van de Ven (Advantages of Dual Frequency PECVD for Deposition of ILD and Passivation Films) in view of US 2018/0151346 to Blanquart.
Abel/van de Ven is discussed above but does not teach depositing other materials beyond SiO and SiN. However, Blanquart teaches a similar process that involves inhibiting deposition inside a trench [0049] and further includes deposition of a wide range of materials including SiN and TiN, TaN, and W precursor [0069-0074]. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to practice the method of Abel and substitute SiN for TiN, TaN, or WN because Blanquart establishes that this type of process is not limited to silicon precursors and includes metal precursors [0069].
Claim(s) 18-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 2023/0307290 to Abel in view of van de Ven (Advantages of Dual Frequency PECVD for Deposition of ILD and Passivation Films) in view of Suzuki (US 2019/0035605).
Abel/van de Ven is discussed above but does not explicitly teach continuous carrier gas throughout deposition cycles. However, Suzuki teaches a PEALD process where the carrier gas is provided in a continuous manner across the deposition cycles (Table 1). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to practice the method of Abel/van de Ven where the carrier gas is provided in a continuous manner throughout the plurality of deposition cycles. Suzuki establishes it is suitable to do so in a PEALD process that includes can include dual frequency [0043].
Response to Arguments
Applicant’s arguments, filed 5/6/26, with respect to the rejection(s) of claim(s) under 103 have been fully considered and are not persuasive.
Applicant argues van de Ven is not analogous. The examiner disagrees. Van de Ven is not limited to particular compositions or intended use, but rather the overall role RF plays in generating a plasma for deposition, which is relevant to both the deposition of an inhibiting layer and also a material layer. For example, in the conclusion section of the document, the main role of high frequency RF is to generate the reactive species and the low frequency is added to control the ion bombardment.
Conclusion
THIS ACTION IS MADE FINAL. 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEX A ROLLAND whose telephone number is (571)270-5355. The examiner can normally be reached M-F 10-6:30.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Curtis Mayes can be reached on 5712721234. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ALEX A ROLLAND/Primary Examiner, Art Unit 1759
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