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 § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 1-25 are is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claims 1 and 13,
Claims 1 and 13 (and throughout depending claims) require a difference of filling heights/speed “is reduced by adjusting a pulse frequency”. However, the claims do not specify a point from which “reduction” is compared to. The “adjusting” of the pulse frequency could simply be an initially chosen set condition which produces a smaller fill height difference when compared with a theoretical deposition condition (i.e. a continuous RF plasma). Alternatively, the claim could be referring starting deposition at a first pulse frequency and “adjusting” the pulse frequency to reduce the difference in fill heights. For the purposes of applying prior art, the claim was interpreted to simply choose a pulse frequency because a comparative reference frequency could be continuous IR plasma, and both high and low frequency “reduce” the difference in fill heights (see applicant’s Fig. 12). This interpretation is reflected in applicants specification [000110] which notes that a reference speed is determined by performing a previous filling operation with an unspecified RF pulse frequency. Accordingly, the execution pulse frequency (claim 1) and pulse frequency (claim 13) can be any set/adjusted pulse plasma frequency.
The depending claims are rejected because they either contain the same issue explicitly or incorporate the same issue from the parent claims 1 and 13.
Claim 13 also introduces the two gaps as “including two gaps” but then later refers to “the at least two gaps”. For antecedent basis consistency, “including two gaps” should be changed to --including at least two gaps--
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 13 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by BLANQUART et al. (US 2020/0013612).
Regarding claim 13,
BLANQUART teaches a deposition process for bottom/gap filling trenches abstract and [0010]. A flowable material is deposited using ALD-like recipes (precursor and reactant [0059]) and allowed to flow to the bottom of a trench [0012]. The flowability of the resulting deposition can be controlled by changing the RF-on time [0076]. The reference further teaches pulse plasma [0088] which has a frequency of one pulse per cycle. The pulsed plasma is expected to yield smaller changes in fill heights when compared to a continuous plasma according to applicant’s disclosure.
The reference notes that there is an optimum flowability that depends on the other parameters [0076]. One of the other parameters is gap size [0077] however in this reference “gap” size is the spacing between capacitively connected electrodes (for plasma).
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.
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.
Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over BLANQUART et al. (US 2020/0013612).
Regarding claim 20,
BLANQUART teaches a flowable CVD process for filling trenches as described above. The reference further teaches trench width of 10-100nm and depth of 30-100nm [0066]. The dimensions overlap the claimed dimensions and are considered prima facie obvious, MPEP 2144.05.I.
Claim(s) 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over BLANQUART et al. (US 2020/0013612) in view of BLANQUART et al. (US 2021/0384030; hereinafter BLANQUART II).
Regarding claim 22,
BLANQUART teaches deposition of a silicon free film but notes that the method of flowable vapor deposition can be used with PEALD-like deposition recipes [0089]. BLANQUART II teaches other known PEALD-like deposition recipes for a flowable vapor deposition include the deposition of silicon nitrides [0050]. At the time of filing the invention it would have been prima facie obvious to one of ordinary skill in the art to use other known PEALD-like recipes in the process of BLANQUART as a substitution of known PEALD recipes.
Allowable Subject Matter
Claims 1-12 and 23-25 would be allowable if rewritten or amended to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action.
Claims 14-19 and 21 and 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.
The following is a statement of reasons for the indication of allowable subject matter:
Regarding claims 1-12 and 23-25,
The examiner was unable to find prior art teaching the change in filling height changing by changing the pulse frequency of a pulsed plasma. Specifically, claim 1 requires a smaller (first) gap to speed up relative to a larger (second) gap.
BLANQUART teaches that there is an optimum flowability that depends on the other parameters [0076]. One of the other parameters is gap size [0077] however in this reference “gap” size is the spacing between capacitively connected electrodes (for plasma).
The reference refers to trench width which corresponds to the claimed gaps. However, most examples do not appear to show a difference in fill rate for different trench widths, see Figs. 13-28. The examples that do show a difference in fill rate show the narrower trench filled faster/higher. This makes sense intuitively, because a perfectly flowable deposition to fill the smaller volume trench faster. This is because the deposition occurring on the upper region (lands) will fill each adjacent gap equally by virtue of flowability. When half of the deposited material flows to a smaller volume, that volume will fill faster than the larger volume. The amount of material filling into a gap could be offset by less material deposition occurring at the bottom surface of a higher aspect ratio trench. However, this does not appear to be an inherent feature in flowable films as demonstrated in BLANQUART. In fact, if there is less deposition at the bottom of the trench there tends to be more deposition at the top of the trench, to BLANQUART [0004] and Fig. 2. This effect should also minimize any self-limiting change in deposition rate that might occur due to a loss in vertical deposition area due to one fill height being higher than another. Despite, the prior art and intuition, applicant’s disclosure plainly shows that the higher diameter trench fills faster Figs. 9-11 and the difference in height can be manipulated by pulse frequency Fig. 12.
Additional art shows the larger gaps fill slower:
US 2024/0258101 Fig. 13A.
US 2024/0222190 Fig. 6.
US 2024/0071749 Fig. 3-5. This reference discusses the capillary effect as contributing to the smaller gaps filling faster.
The examiner was unable to find prior art teaching the use of a smaller pulse frequency to increase gap fill speed/height of a smaller gap while also decreasing fill speed/height of a larger gap.
Depending claims 2-12 and 23-25 are allowable by virtue of dependency.
Regarding claims 14 and 16,
The claims require setting a reference pulse frequency at an arbitrary reference point. The claim also requires setting an execution pulse frequency smaller than the reference pulse frequency. The examiner could find no reason to set an arbitrary reference point when the method does not perform any steps at that set point and the use a smaller frequency. The examiner also notes that a smaller pulse frequency does not appear to always decrease the difference in film height. For example, depending on the size of the gap, the change in relative film height may not change with high/low frequency, see Fig. 12 with CD size 190nm.
This table in fig. 12 also shows that a continuous plasma causes a high difference in film height. A very low frequency might be expected to be similar to the continuous plasma, but a “low” frequency shows improved smaller height differences. But, as the frequency continues to increase the “high” frequency again causes bigger height differences. Accordingly, there appears to be a curve in which an optimum frequency could be found that is not so low as to be similar to a continuous plasma, but not too fast as to be considered “high” frequency. An arbitrary reference point on this curve may not always result in a decreased height difference when pulse frequency is lowered.
Regarding claim 15,
Claim 15 is allowable by virtue of dependency. The limitations are also allowable for similar reasons to those described above for claim 1.
Regarding claims 17, 19, and 21,
The claims are allowable by virtue of dependency from claim 14. For claim 19, the examiner also notes the RF pulse frequency is distinguished from RF power frequency.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AUSTIN MURATA whose telephone number is (571)270-5596. The examiner can normally be reached M-F 8:30-5.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, MICHAEL CLEVELAND can be reached at 571272-1418. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/AUSTIN MURATA/Primary Examiner, Art Unit 1712