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
Applicant's election with traverse of claims 1-15 in the reply filed on 7/21/2026 is acknowledged. The traversal is on the ground(s) that there is no unreasonable search and examination burden exists because a search of the subject matter claimed in Group I directed to methods for forming a contact structure on a semiconductor substrate would yield relevant references, if any, equally applicable to the subject matter of a processing system capable of performing such methods as claimed in Group II. This is not found persuasive because the inventions (Claims 1-15 dawn to a Process and Claims 16-20 drawn to an Apparatus )are distinct because the process can be performed by a different apparatus (single chamber system). Therefore, the restriction between the process and apparatus groups remain proper because the inventions are independent and distinct.
The requirement is still deemed proper and is therefore made FINAL.
Claims 16-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 7/21/2026.
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(s) 1-6,8,9,12-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang (US Pub no. 20200098572 A1) in view of Ishizaki (US Pub no. 2024/0379377 A1) in view of Huang (US Pub no. 2021/0320061 A1).
Regarding claim 1, Wang et al discloses A method of forming a contact structure(228) on a semiconductor substrate(102), comprising: selectively depositing a metal silicide layer (333 of 239)over a contact formed within a cavity of a substrate (102)and a bottom surface of the cavity using a selective deposition process[0054][0072], the selective deposition process forming a residual layer(230 + unreacted portions of silicon -comprising layer and/ or metal comprising layer) on a surface of a dielectric layer(226 or 244 or 246) forming sidewalls of the cavity[0072-0073] wherein a thickness of the metal silicide layer (333 of 239)deposited over the contact is greater than a thickness of the residual layer(230 + unreacted portions of silicon -comprising layer and/ or metal comprising layer) [0072-0073];
removing at least a portion of the residual layer (unreacted portions of silicon -comprising layer and or metal comprising layer) formed on the dielectric layer(226 or 244 or 246) using an etching process[0073]; and depositing a metal fill (234)over the metal silicide layer(333) remaining over the contact after removing the at least the portion of the residual layer formed on the dielectric layer (246) [0086].
Wang et al fails to teach wherein the etching process comprises exposing the metal selectively deposited layer to a metal halide containing precursor; and using a selective metal fill process.
However, Ishizaki et al discloses an etching process removing titanium adhesions 965)by supplying WCl5[0068]. Since using a metal halide to remove unreacted Ti is one of finite solutions to suppress wiring resistance as taught by Ishizaki et al [0067]. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to try in Wang et al since a person of ordinary skill has good reason to pursue the known options within his or her technical grasp. If this leads to the anticipated success, it is likely that product [was] not of innovation but of ordinary skill and common sense. KSR, 550 U.S. at 421, 82 USPQ2d at 1397.
Wang et al in view of Ishizaki et al discloses all the claim limitations above but fails to teach using a selective metal fill process.
However, Huang et al discloses a contact formation method using a selective metal fill process [0036][0023]. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Wang et al & Ishizaki et al with the teachings of Huang et al to provide a low contact via resistance.
Regarding claim 2, Ishizaki wherein the metal halide containing precursor essentially comprises tungsten pentachloride (WCI₅)[0067].
Regarding claim 3, Wang et al discloses wherein the metal silicide layer(239/333) comprises titanium silicide (TixSiy)[0083][0053].
Regarding claim 4, Ishizaki et al disclose wherein the etching process comprises a soaking process that comprises exposing at least the residual layer(Ti adhesions )to an amount of the metal halide containing precursor for a first period of time[0068].
Regarding claim 5, Ishizaki et al discloses wherein the soaking process comprises exposing the substrate to an amount of a tungsten (W) precursor [0068]
Regarding claim 6, (which depends from claim 5), because claim 5 recites an alternative (a tungsten precursor or Molybdenum precursor) and the limitation is satisfied by the tungsten precursor taught by Ishizaki et al , the specific molybdenum pentachloride precursor of claim 6 is not required.
Regarding claim 8, Wang et al discloses , wherein the metal fill layer(234) comprises tungsten (W) or molybdenum (Mo)[0052].
Regarding claim 9, Huang et al discloses wherein the selective metal fill process is a CVD process[0036].
Regarding claim 12, Wang et al discloses A method of forming a contact structure on a semiconductor substrate(102), comprising: selectively depositing a metal silicide layer (333 of 239)over a contact(331) formed within a cavity of a substrate(102) and a bottom surface of the cavity (contact openings formed in 236,246,226, & 224)using a selective deposition process[0054][0072], the selective deposition process forming a residual layer(230 + unreacted portions of silicon -comprising layer and/ or metal comprising layer) on a surface of a dielectric layer(236,246,226, or 224) forming sidewalls of the cavity [0072-0073], wherein a thickness of the metal silicide layer(333 of 239) deposited over the contact is greater than a thickness of the residual layer(230 + unreacted portions of silicon -comprising layer and/ or metal comprising layer) [0072-0073];
removing at least a portion of the residual layer(unreacted portions of silicon -comprising layer and or metal comprising layer) using a soaking process[0073], the
soaking process comprising exposing the metal silicide layer(333 of 239)[0073]
; and depositing a metal fill (234)over the metal silicide layer (333 of 239)remaining over the contact (331)after removing the at least the portion of the residual layer(unreacted portions of silicon -comprising layer and or metal comprising layer) formed on the dielectric layer (236,246,226, or 244)[0086].
Wang et al fails to teach soaking process comprising exposing the metal silicide layer to an amount of a metal halide containing precursor for a period of time; and using a selective metal fill process.
However, Ishizaki et al discloses a soaking process to removing titanium adhesions 965)by supplying WCl5[0068]. Since using a metal halide to remove unreacted Ti is one of finite solutions to suppress wiring resistance as taught by Ishizaki et al [0067]. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to try in Wang et al with the teachings of Ishizaki et al such that exposing the metal silicide layer to an amount of a metal halide containing precursor for a period of time results since a person of ordinary skill has good reason to pursue the known options within his or her technical grasp. If this leads to the anticipated success, it is likely that product [was] not of innovation but of ordinary skill and common sense. KSR, 550 U.S. at 421, 82 USPQ2d at 1397.
Wang et al in view of Ishizaki et al discloses all the claim limitations above but fails to teach using a selective metal fill process.
However, Huang et al discloses a contact formation method using a selective metal fill process [0036][0023]. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Wang et al & Ishizaki et al with the teachings of Huang et al to provide a low contact via resistance.
Regarding claim 13, Ishizaki et al discloses wherein the metal halide containing precursor essentially comprises tungsten pentachloride (WCI₅)[0067].
Regarding claim 14, Wang et al discloses wherein the metal silicide layer comprises titanium silicide (TixSiy)[0072].
Claim(s) 7 & 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang (US Pub no. 20200098572 A1) in view of Ishizaki (US Pub no. 2024/0379377 A1) in view of Huang (US Pub no. 2021/0320061 A1) as applied to claim 1 and further in view of Kuroda (US Pub no. 2019/0148224 A1).
Regarding claim 7, Wang et as modified by Ishizaki et al & Huang et al discloses all the claim limitations of claim 1 but fails to teach wherein selectively depositing a metal fill over the metal silicide layer comprises exposing the metal silicide layer to a metal halide containing precursor and a reducing agent.
However, Kuroda et al discloses selectively depositing a metal fill (310) using a metal halide containing precursor and a reducing agent[0057][0060-0061]. Since performing a selective deposition process using a metal halide containing precursor and a reducing agent is one of finite solution for depositing metal while eliminating the need for subsequent patterning steps as taught by Kuroda et al It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to try in Wang et al , Ishizaki et al & Huang et al such that selectively depositing a metal fill over the metal silicide layer comprises exposing the metal silicide layer to a metal halide containing precursor and a reducing agent results since a person of ordinary skill has good reason to pursue the known options within his or her technical grasp. If this leads to the anticipated success, it is likely that product [was] not of innovation but of ordinary skill and common sense. KSR, 550 U.S. at 421, 82 USPQ2d at 1397.
Regarding claim 15, Wang et as modified by Ishizaki et al & Huang et al discloses all the claim limitations of claim 12 but fails to teach wherein selectively depositing a metal fill over the metal silicide layer comprises exposing the metal silicide layer to a metal halide containing precursor and a reducing agent.
However, Kuroda et al discloses selectively depositing a metal fill (310) using a metal halide containing precursor and a reducing agent[0057][0060-0061]. Since performing a selective deposition process using a metal halide containing precursor and a reducing agent is one of finite solution for depositing metal while eliminating the need for subsequent patterning steps as taught by Kuroda et al It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to try in Wang et al , Ishizaki et al & Huang et al such that selectively depositing a metal fill over the metal silicide layer comprises exposing the metal silicide layer to a metal halide containing precursor and a reducing agent results since a person of ordinary skill has good reason to pursue the known options within his or her technical grasp. If this leads to the anticipated success, it is likely that product [was] not of innovation but of ordinary skill and common sense. KSR, 550 U.S. at 421, 82 USPQ2d at 1397.
Allowable Subject Matter
Claims 10 & 11 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 cited reference, Xie (US Pub no. 2023/0178422 A1) is noted as general background of the art.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to LATANYA N CRAWFORD EASON whose telephone number is (571)270-3208. The examiner can normally be reached Monday-Friday 8:30 AM-4:30 PM.
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, Steven B Gauthier can be reached at (571)270-0373. 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.
/LATANYA N CRAWFORD EASON/Primary Examiner, Art Unit 2813
Prosecution Insights