Prosecution Insights
Last updated: April 19, 2026
Application No. 18/662,672

METHOD FOR ETCHING AN ETCH LAYER

Final Rejection §102§103
Filed
May 13, 2024
Examiner
CULBERT, ROBERTS P
Art Unit
1716
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Lam Research Corporation
OA Round
2 (Final)
82%
Grant Probability
Favorable
3-4
OA Rounds
2y 5m
To Grant
78%
With Interview

Examiner Intelligence

Grants 82% — above average
82%
Career Allow Rate
659 granted / 809 resolved
+16.5% vs TC avg
Minimal -4% lift
Without
With
+-3.6%
Interview Lift
resolved cases with interview
Typical timeline
2y 5m
Avg Prosecution
20 currently pending
Career history
829
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
42.6%
+2.6% vs TC avg
§102
35.1%
-4.9% vs TC avg
§112
9.4%
-30.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 809 resolved cases

Office Action

§102 §103
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 Arguments Applicant's arguments filed 8/4/25 have been fully considered. Applicant has argued that claim 1 is not anticipated by Hudson because Hudson teaches (Paragraph 139) use of WF6 with NH3 or H2. However, the argument is not persuasive to overcome the rejection because Hudson teaches a limited number of possible combinations including a first reactant gas comprising WF6 (Paragraphs 83, 130, 138) and a second reactant gas comprising an oxygen containing component (Paragraphs 83, 126) to form the protective sidewall coating (310) and therefore teaches the combination of WF6 and an oxygen containing component with sufficient specificity for anticipation. Applicant has argued that it would not be obvious to use the selective deposition of Omura in the conformal atomic layer method of Hudson. However, the argument is not persuasive to overcome the rejection because Hudson teaches the conformal atomic layer deposition method including a first reactant gas comprising WF6 (Paragraphs 83, 130, 138) and a second reactant gas comprising an oxygen containing component (Paragraphs 83, 126) to form the protective sidewall coating (310). Omura further teaches tungsten oxide is known in the art for the sidewall protection layer (72) in a dielectric stack etching process (Paragraph 40). It would have been obvious to one of ordinary skill in the art at the time of the claimed invention to provide tungsten oxide using a first reactant gas comprising tungsten such as tungsten hexafluoride (WF6) and a second reactant gas comprising an oxygen containing component to form the protective sidewall coating (310) in the method of Hudson with predictable results since Omura teaches tungsten oxide is known in the art to be a suitable sidewall protection layer for dielectric stack etching. Applicant has argued that nothing in the cited references teaches a using a first reactant gas comprising tungsten such as tungsten hexafluoride (WF6) and a second reactant gas comprising COS, CO2, CO, SO2, O2 or O3. However, the argument is not persuasive to overcome the rejection because Hudson teaches the conformal atomic layer deposition method including a first reactant gas comprising WF6 (Paragraphs 83, 130, 138) and a second reactant gas comprising an oxygen containing component (Paragraphs 83, 126) such as oxygen (O2), ozone (O3), carbonyl sulfide (COS) carbon monoxide (CO) carbon dioxide (CO2), sulfur dioxide (SO2). Applicant has argued that it would not be obvious to use the plasma-less deposition of Qian in the conformal atomic layer method of Hudson since Qian does not expressly teach tungsten oxide. However, the argument is not persuasive to overcome the rejection because Hudson teaches plasma or thermal based deposition may be used (Paragraph 89). Qian teaches thermally activated plasma-less adsorption of metal containing precursors such as metal halides. It would have been obvious to one of ordinary skill in the art at the time of the claimed invention to provide a plasma-less first reactant gas in the method of Hudson to provide ultrathin ALD films with predictable results. 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. Claims 1-8, 10 and 20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by US Publication 2017/0076945 to Hudson et al. Regarding Claim 1, Hudson teaches a method of etching features in a stack comprising a dielectric material (303) below a mask (306) on a substrate, the method comprising: (a) generating an etch plasma from an etch gas (Paragraphs 45 and 110), exposing the stack to the etch plasma, and partially etching features in the stack (See Paragraphs 75 and 116) in a plasma processing chamber; (b) after (a) providing a deposition process performed in-situ (Paragraphs 96, 148 and 165) in the plasma processing chamber to deposit a protective film (310) comprising a plurality of cycles (Figure 2A), wherein each cycle comprises: (i) exposing the stack to a first reactant gas comprising WF6 (Paragraphs 83, 130, 138), wherein the first reactant gas is adsorbed (Paragraph 79) onto the stack; and (ii) exposing the stack to a plasma formed from a second reactant gas, wherein the plasma formed from the second reactant gas reacts with adsorbed first reactant gas to form the protective film over the stack (Paragraphs 79 and 81), wherein the second reactant gas comprises an oxygen containing component to provide oxidation (Paragraphs 83, 126) wherein the deposition process further comprises maintaining a stack temperature below 150° C (Paragraph 142). Regarding Claim 2, Hudson teaches (Figure 2A and Paragraph 79) repeating (a)- (b) at least one time in-situ in the plasma processing chamber. Regarding Claim 3, Hudson teaches the second reactant gas may be oxygen containing reactant (Paragraph 83) and comprises at least one of COS, CO2, CO, SO₂, O2, or O3 (Paragraph 126). Regarding Claim 4, Hudson teaches (Paragraph 36) the stack comprises SiO2. Regarding Claim 5, Hudson teaches (Paragraph 37) the stack further comprises a hardmask. Regarding Claim 6, Hudson teaches the hardmask comprises one or more of amorphous carbon, boron doped carbon, metal doped carbon, or polysilicon (Paragraph 37). Regarding Claim 7, Hudson teaches (Paragraph 141) step (b) is performed for 2 to 100 cycles. Regarding Claim 8, Hudson teaches (Paragraphs 79 and 141) each cycle further comprises: purging the first reactant gas after exposing the stack to the first reactant gas and before exposing the stack to the plasma formed by the second reactant gas; and purging the plasma formed from the second reactant gas, after exposing the stack to the plasma formed from the second reactant gas. Regarding Claim 10, Hudson teaches (Paragraphs 77 and 81) step (b) is an atomic layer deposition. Regarding Claim 20, Hudson teaches (Fig. 2C and 3B) providing the deposition on sidewalls of the features. 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 9 is rejected under 35 U.S.C. 103 as being unpatentable over US Publication 2017/0076945 to Hudson et al. in view of US Publication 2017/0271170 to Omura et al. Regarding Claim 9, as applied above to Claim 1, Hudson teaches the method of the invention substantially as claimed, but does not expressly teach the exposing the stack to the first reactant gas is a plasma-less step. However, Qian teaches (Paragraph 9 in context) a plasma-less first step may be performed to adsorb a first precursor in an atomic layer deposition process. It would have been obvious to one of ordinary skill in the art at the time of the claimed invention to provide a plasma-less first reactant gas in the method of Hudson with predictable results. Claims 1-10 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over US Publication 2017/0076945 to Hudson et al. in view of US Publication 2017/0271170 to Omura et al. and US Publication 2016/0276148 to Qian et al. Regarding Claim 1, Hudson teaches a method of etching features in a stack comprising a dielectric material (303) below a mask (306) on a substrate, the method comprising: (a) generating an etch plasma from an etch gas (Paragraphs 45 and 110), exposing the stack to the etch plasma, and partially etching features in the stack (Paragraphs 75 and 116) in a plasma processing chamber; (b) after (a) providing a deposition process performed in-situ (Paragraphs 96, 148 and 165) in the plasma processing chamber to deposit a protective film (310) comprising a plurality of cycles (Figure 2A), wherein each cycle comprises: (i) exposing the stack to a first reactant gas comprising WF6 (Paragraphs 83, 130,138), wherein the first reactant gas is adsorbed onto the stack; and (ii) exposing the stack to a plasma formed from a second reactant gas, wherein the plasma formed from the second reactant gas reacts with adsorbed first reactant gas to form the protective film over the stack (Paragraphs 79 and 81), wherein the second reactant gas comprises an oxygen containing component to provide oxidation (Paragraphs 83, 126) wherein the deposition process further comprises maintaining a stack temperature below 150° C (Paragraph 142). Regarding Claim 1, as applied above, Hudson teaches a first reactant gas comprising WF6 (Paragraphs 83, 130, 138) and a second reactant gas comprising an oxygen containing component (Paragraphs 83, 126) to form the protective sidewall coating (310) with sufficient specificity for anticipation. However, Omura further teaches tungsten oxide is known in the art for the sidewall protection layer (72) in a dielectric stack etching process (Paragraph 40). It would have been obvious to one of ordinary skill in the art at the time of the claimed invention to provide tungsten oxide using a first reactant gas comprising tungsten such as tungsten hexafluoride (WF6) and a second reactant gas comprising an oxygen containing component to form the protective sidewall coating (310) in the method of Hudson with predictable results. Regarding Claim 1, as applied above, Hudson teaches (Paragraph 142) deposition temperatures may be maintained 20-200° C and therefore teaches a stack temperature below 150° C with sufficient specificity for anticipation. However, Qian teaches atomic layer deposition of an oxide may occur below 100° C or 50° C (Paragraph 35). It would have been obvious to one of ordinary skill in the art at the time of the claimed invention to provide a stack temperature below 150° C in the method of Hudson to deposit an oxide protective sidewall coating with predictable results. Regarding Claim 2, Hudson teaches (Figure 2A and Paragraph 79) repeating (a)- (b) at least one time in-situ in the plasma processing chamber. Regarding Claim 3, Hudson teaches the second reactant gas may be oxygen containing reactant (Paragraph 83) and comprises at least one of COS, CO2, CO, SO₂, O2, or O3 (Paragraph 126). Regarding Claim 4, Hudson teaches (Paragraph 36) the stack comprises SiO2. Regarding Claim 5, Hudson teaches (Paragraph 37) the stack further comprises a hardmask. Regarding Claim 6, Hudson teaches the hardmask comprises one or more of amorphous carbon, boron doped carbon, metal doped carbon, or polysilicon (Paragraph 37). Regarding Claim 7, Hudson teaches (Paragraph 141) step (b) is performed for 2 to 100 cycles. Regarding Claim 8, Hudson teaches (Paragraphs 79 and 141) each cycle further comprises: purging the first reactant gas after exposing the stack to the first reactant gas and before exposing the stack to the plasma formed by the second reactant gas; and purging the plasma formed from the second reactant gas, after exposing the stack to the plasma formed from the second reactant gas. Regarding Claim 9, Hudson teaches plasma or thermal based deposition may be used (Paragraph 89), but does not expressly teach the exposing the stack to the first reactant gas is a plasma-less step. However, Qian teaches (Paragraph 9 in context) a plasma-less first step may be performed to adsorb a first precursor in an atomic layer deposition process. It would have been obvious to one of ordinary skill in the art at the time of the claimed invention to provide a plasma-less first reactant gas in the method of Hudson with predictable results. Regarding Claim 10, Hudson teaches (Paragraphs 77 and 81) step (b) is an atomic layer deposition. Regarding Claim 20, Hudson teaches (Fig. 2C and 3B) providing the deposition on sidewalls of the features. Allowable Subject Matter Claim 19 is 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. 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Roberts P Culbert whose telephone number is (571)272-1433. The examiner can normally be reached Monday thru Thursday 7:30 AM-6 PM EST. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Parviz Hassanzadeh can be reached at 571-272-1435. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /ROBERTS P CULBERT/Primary Examiner, Art Unit 1716
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Prosecution Timeline

May 13, 2024
Application Filed
May 02, 2025
Non-Final Rejection — §102, §103
Aug 04, 2025
Response Filed
Aug 04, 2025
Response after Non-Final Action
Feb 21, 2026
Final Rejection — §102, §103 (current)

Precedent Cases

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
82%
Grant Probability
78%
With Interview (-3.6%)
2y 5m
Median Time to Grant
Moderate
PTA Risk
Based on 809 resolved cases by this examiner. Grant probability derived from career allow rate.

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