Prosecution Insights
Last updated: April 19, 2026
Application No. 18/620,417

HARD MASK PROTECTION OF METAL INTERCONNECTS

Non-Final OA §103
Filed
Mar 28, 2024
Examiner
LU, JIONG-PING
Art Unit
1713
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Tokyo Electron Limited
OA Round
1 (Non-Final)
83%
Grant Probability
Favorable
1-2
OA Rounds
2y 3m
To Grant
91%
With Interview

Examiner Intelligence

Grants 83% — above average
83%
Career Allow Rate
779 granted / 935 resolved
+18.3% vs TC avg
Moderate +8% lift
Without
With
+7.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 3m
Avg Prosecution
54 currently pending
Career history
989
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
47.5%
+7.5% vs TC avg
§102
27.9%
-12.1% vs TC avg
§112
16.2%
-23.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 935 resolved cases

Office Action

§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 . 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 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. 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 of this title, 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. 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. Claims 1, 4-7, 11-14 and 18-20 are rejected under 35 U.S.C. 103 as being obvious over Jiang et al. (US20210125864). Regarding claim 1, Jiang discloses a method (abstract) comprising: depositing a first layer having a first electrochemical potential over a substrate (layer 112 reads on a first layer having a first electrochemical potential, paragraph 0052 and Fig. 1A); depositing a second layer having a second electrochemical potential over the first layer, (layer 114 reads on a second layer having a second electrochemical potential, paragraph 0054 and Fig. 1A); creating an opening through the second layer (paragraph 0059, and a drawing below illustrating an intermediate structure with the opening in the second layer during the plasma etching process); and extending the opening through the first layer by etching the first layer and the second layer (paragraph 0059 and Fig. 2A), wherein at least some of the second layer is deposited over the first layer on sidewalls of the opening during the extending (layer 114 and layer 116 are both parts of the mask used during the plasma etching of layer 108, Fig. 2A and paragraph 0059; therefore, at least some of the second layer, layer 114, is deposited over the first layer on sidewalls of the opening during the extending due to the mask sputtering effect discussed in paragraph 0062). PNG media_image1.png 200 400 media_image1.png Greyscale Jiang does not expressly disclose wherein the second electrochemical potential is less than the first electrochemical potential. However, Jiang discloses limited number of choices for the first layer (layer 112 is selected from one or more of tungsten (W), cobalt (Co), ruthenium (Ru), molybdenum (Mo), aluminum (Al), copper (Cu), silicide, graphene, or combinations thereof, paragraph 0052 and Fig. 1A) and the second layer (layer 116 is selected from one or more of tantalum (Ta), tantalum nitride (TaN), titanium (Ti), titanium nitride (TiN), W, Co, Ru, niobium (Nb), niobium nitride (NbN), and combinations thereof, paragraph 0054 and Fig. 1A). There are multiple pairs of the first layer and the second layer disclosed by Jiang satisfy the relative electrochemical potentials as recited in the instant claim. It has been held that choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success is obvious. See MPEP 2143 I.(E). Regarding claim 4, Jiang discloses wherein the second layer deposited over the first layer on sidewalls of the opening seals the first layer at the sidewalls (paragraph 0062 and Fig. 4). Regarding claim 5, Jiang discloses wherein etching the first layer and the second layer further comprises: etching using reactive ion etching (paragraph 0059). Regarding claim 6, Jiang discloses wherein: the first layer comprises Mo (paragraph 0052), and the second layer comprises at least one of: Ti, Ta, Nb, or Co (paragraph 0054). Regarding claim 7, Jiang discloses a process (abstract) comprising: depositing a first metal over a semiconductor substrate comprising silicon, the first metal having a first electrochemical potential and forming a first layer (silicon substrate 102, paragraph 0048 and Fig. 1A; layer 112 reads on a first layer having a first electrochemical potential, paragraph 0052 and Fig. 1A); depositing a second metal over the first layer and forming a second layer (layer 114 reads on a second layer having a second electrochemical potential, paragraph 0054 and Fig. 1A); patterning the second layer to form a hard mask having an opening through the hard mask (paragraph 0059, and a drawing below illustrating an intermediate structure with the opening in the second layer); and etching the hard mask to extend the opening through the first layer, and, during the etching, sputtering the second metal over the first metal at sidewalls of the opening (layer 114 and layer 116 are both parts of the mask used during the plasma etching of layer 108, Fig. 2A and paragraph 0059; therefore, some of the second metal is sputtered over the first metal at sidewalls of the opening due to the mask sputtering effect discussed in paragraph 0062). PNG media_image1.png 200 400 media_image1.png Greyscale Jiang does not expressly disclose wherein the second metal having a second electrochemical potential less than the first electrochemical potential. However, Jiang discloses limited number of choices for the first layer (layer 112 is selected from one or more of tungsten (W), cobalt (Co), ruthenium (Ru), molybdenum (Mo), aluminum (Al), copper (Cu), silicide, graphene, or combinations thereof, paragraph 0052 and Fig. 1A) and the second layer (layer 116 is selected from one or more of tantalum (Ta), tantalum nitride (TaN), titanium (Ti), titanium nitride (TiN), W, Co, Ru, niobium (Nb), niobium nitride (NbN), and combinations thereof, paragraph 0054 and Fig. 1A). There are multiple pairs of the first layer and the second layer satisfy the relative electrochemical potentials as recited in the instant claim. It has been held that choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success is obvious. See MPEP 2143 I.(E). Regarding claim 11, Jiang discloses wherein sputtering the second metal over the first metal at sidewalls of the opening further comprises: sealing the first layer from a surrounding environment at the sidewalls (paragraph 0062 and Fig. 4). Regarding claim 12, Jiang discloses wherein etching the hard mask further comprises: etching using reactive ion etching (paragraph 0059). Regarding claim 13, Jiang discloses wherein: the first layer comprises Mo (paragraph 0052), and the second layer comprises at least one of: Ti, Ta, Nb, or Co (paragraph 0054). Regarding claim 14, Jiang discloses a process (abstract) comprising: providing a plurality of layers, at least some of the layers comprising a metal mask layer, a first metal layer under the metal mask layer, and a silicon-containing layer under the first metal layer (layer 114 reads on a metal mask layer, paragraph 0054 and Fig. 1A; layer 112 reads on a first metal layer, paragraph 0052 and Fig. 1A; silicon substrate 102 reads on a silicon-containing layer, paragraph 0048 and Fig. 1A); defining an opening in the metal mask layer (paragraph 0059, and a drawing below illustrating an intermediate structure with the opening in the metal mask layer layer); etching the metal mask layer through the opening to define sidewalls of the metal mask layer and of the first metal layer (paragraph 0059 and the illustrate drawing below); and during the etching, causing a second metal from the metal mask layer to be sputtered on the sidewalls over the first metal layer (layer 114 and layer 116 are both parts of the mask used during the plasma etching of layer 108, Fig. 2A and paragraph 0059; therefore, some metal from the metal mask layer is sputtered on the sidewalls over the first metal layer due to the mask sputtering effect discussed in paragraph 0062). PNG media_image1.png 200 400 media_image1.png Greyscale Jiang does not expressly disclose wherein the metal mask layer having a second electrochemical potential that is less than a first electrochemical potential of the first metal layer. However, Jiang discloses limited number of choices for the first layer (layer 112 is selected from one or more of tungsten (W), cobalt (Co), ruthenium (Ru), molybdenum (Mo), aluminum (Al), copper (Cu), silicide, graphene, or combinations thereof, paragraph 0052 and Fig. 1A) and the second layer (layer 116 is selected from one or more of tantalum (Ta), tantalum nitride (TaN), titanium (Ti), titanium nitride (TiN), W, Co, Ru, niobium (Nb), niobium nitride (NbN), and combinations thereof, paragraph 0054 and Fig. 1A). There are multiple pairs of the first layer and the second layer satisfy the relative electrochemical potentials as recited in the instant claim. It has been held that choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success is obvious. See MPEP 2143 I.(E). Regarding claim 18, Jiang discloses wherein causing the second metal from the metal mask layer to be sputtered on the sidewalls over the first metal layer further comprises: sealing the first metal layer from the environment at the sidewalls (paragraph 0062 and Fig. 4). Regarding claim 19, Jiang discloses wherein etching the metal mask layer further comprises: etching using reactive ion etching (paragraph 0059). Regarding claim 20, Jiang discloses wherein: the first layer comprises Mo (paragraph 0052), and the second layer comprises at least one of: Ti, Ta, Nb, or Co (paragraph 0054). Allowable Subject Matter Claims 2-3, 8-10 and 15-17 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. The following is a statement of reasons for the indication of allowable subject matter: Regarding claim 2, the cited prior art of record, taken either alone or in combination, fails to disclose or render obvious a method comprising: exposing the sidewalls to atmosphere to oxidize the second layer deposited on the sidewalls, in the context of the instant claim. The closest cited prior art of Jiang discloses the deposit on the sidewall comprises oxide from the mask without exposing the sidewalls to atmosphere (paragraph 0062). Regarding claim 3, it is dependent on claim 2. Regarding claim 8, the cited prior art of record, taken either alone or in combination, fails to disclose or render obvious a method comprising: removing the second layer to expose the first layer, and oxidizing the second metal deposited on the sidewalls, in the context of the instant claim. The closest cited prior art of Jiang discloses that the second layer remains on the first layer, and the deposit on the sidewall comprises oxide from the mask without oxidizing the second metal deposited on the sidewalls (paragraphs 0062 and 0065; Fig. 6A). Regarding claims 9-10, it is dependent on claim 8. Regarding claim 15, the cited prior art of record, taken either alone or in combination, fails to disclose or render obvious a method comprising: removing the metal mask layer to expose the first metal layer, and oxidizing the second metal deposited on the sidewalls by exposing the first metal layer to oxygen, in the context of the instant claim. The closest cited prior art of Jiang discloses that the metal mask layer remains on the first metal layer, and the deposit on the sidewall comprises oxide from the mask without oxidizing the second metal deposited on the sidewalls (paragraphs 0062 and 0065; Fig. 6A). Regarding claims 16-17, it is dependent on claim 15. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Meier et al. (US11011381) discloses a wet etching process to pattern a platinum layer using a hard mask layer comprising SiO2 (lines 4-22, column 2). Any inquiry concerning this communication or earlier communications from the examiner should be directed to JIONG-PING LU whose telephone number is (571) 270-1135. The examiner can normally be reached on M-F: 9:00am – 5:00pm. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Joshua L Allen, can be reached at telephone number (571)270-3176. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from Patent Center. Status information for published applications may be obtained from Patent Center. Status information for unpublished applications is available through Patent Center for authorized users only. Should you have questions about access to Patent Center, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). 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) Form at https://www.uspto.gov/patents/uspto-automated- interview-request-air-form. /JIONG-PING LU/ Primary Examiner, Art Unit 1713
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Prosecution Timeline

Mar 28, 2024
Application Filed
Apr 08, 2026
Non-Final Rejection — §103 (current)

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

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Prosecution Projections

1-2
Expected OA Rounds
83%
Grant Probability
91%
With Interview (+7.9%)
2y 3m
Median Time to Grant
Low
PTA Risk
Based on 935 resolved cases by this examiner. Grant probability derived from career allow rate.

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