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 without traverse of Group I (Claims 1-16 and new Claims 21-24) in the reply filed on 12/1/2025 is acknowledged.
Claims 17-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 12/1/2025.
Preliminary Amendment & Claims’ Status
Applicant’s 12/1/2025 preliminary amendment to cancel Claims 17-20 is acknowledged.
Claims 1-16 and 21-24 are currently pending and being examined, being drawn to elected invention Group I. No claims have been amended. Claims 17-20 have been cancelled by the applicant. New Claims 21-24 have been added.
Information Disclosure Statement
The information disclosure statement (IDS) was submitted on 7/12/2023. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Claim Rejections - 35 USC § 103
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 (i.e., changing from AIA to pre-AIA ) 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.
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.
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 1-3 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Hsieh et al (US 2019/0140076 A1, hereafter Hsieh) in view of Lai et al (CN 114496918 A, hereafter Lai).
Re Claim 1, Hsieh discloses a method, comprising:
forming a fin base (26; [0015]) on a substrate (20; [0015]);
epitaxially growing a source/drain (S/D) region (44; [0022]) on the fin base (26; [0022]);
forming a contact opening (“openings”; [0038]) on the S/D region (44; [0038]);
forming a semiconductor nitride layer (50; [0025]) on a sidewall of the contact opening (“openings”; [0026], particularly the undensified vertical portion 51, “on” the bottom of);
performing a densification process on the semiconductor nitride layer (50; [0026]) to form a densified semiconductor nitride layer (53; [0026]);
forming a silicide layer (68; [0038]) on an exposed surface of the S/D region (44; [0038]) in the contact opening (“openings”; [0038]); and
forming a contact plug (70; [0038]) in the contact opening (“openings”; [0038]).
Hsieh does not explicitly disclose forming a via structure in the contact plug (70).
However, Lai teaches a method (FIG. 14; pg. 6, para. 7) comprising forming a via structure (80; pg. 6, para. 7) in the contact plug (68; pg. 6, para. 7).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the limitations disclosed by Hsieh with the limitations taught by Lai to form a via structure in the contact plug (Hsieh: 70) to establish source/drain contact through subsequent processing layers as taught by Lai (pg. 7, para. 5).
Re Claim 2, Hsieh and Lai teach the method according to Claim 1, while Hsieh further teaches wherein performing the densification process comprises performing a plasma treatment ([0027]), an ultra-violet (UV) treatment, or a thermal treatment on the semiconductor nitride layer (50; [0027]).
Re Claim 3, Hsieh and Lai teach the method according to Claim 1, while Hsieh further teaches wherein performing the densification process comprises exposing the semiconductor nitride layer (50) to a nitrogen and hydrogen plasma ([0027]).
Re Claim 7, Hsieh and Lai teach the method according to Claim 1, while Lai further teaches wherein forming the silicide layer (66; pg. 5, para. 5) comprises:
depositing a metal layer (62; pg. 5, para. 5) with a first metal portion (62, bottom portion that converts to silicide 66; pg. 5, para. 5) on the exposed surface of the S/D region (42; pg. 5, para. 5) and a second metal portion (62, sidewalls portion that does not convert to silicide 66; pg. 5, para. 5); and
converting the first metal portion (62, bottom portion that converts to silicide 66) to the silicide layer (66; pg. 5, para. 5).
Lai does not explicitly disclose the metal layer’s second portion (Lai: 62, sidewalls portion that does not convert to silicide 66) is on a densified semiconductor nitride layer, but Lai teaches formation of a contact plug with a metal layer (Lai: 62). Thus, in combination with Hsieh and the use of Lai’s contact plug (Lai: 62, 64, 68), the metal layer’s second portion (Lai: 62, sidewalls portion that does not convert to silicide 66) would be “on” top of the densified semiconductor nitride layer (Hsieh: 53).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method as discussed for Claim 1 with the limitations taught by Lai to utilize a multi-portioned metal layer (Lai: 62) in formation of the silicide layer (Hsieh: 68) to simultaneously begin formation of the overlying contact plug during formation of the silicide layer (Hsieh: 68) as taught by Lai (pg. 5, para. 5).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Hsieh and Lai, as applied to Claim 1, further in view of Yong et al (US 2023/0335399 A1, hereafter Yong).
Re Claim 4, Hsieh and Lai teach the method according to Claim 1, but they do not explicitly disclose wherein performing the densification process comprises exposing the semiconductor nitride layer (Hsieh: 50) to an ultra-violet (UV) radiation.
However, Yong teaches a method (FIG. 3; [0017]) comprising wherein performing the densification process comprises exposing the semiconductor nitride layer (“silicon nitride”; [0017]) to an ultra-violet (UV) radiation ([0017]).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method as discussed for Claim 1 with the limitations taught by Yong to utilize UV treatment for densifying the semiconductor nitride layer (Hsieh: 50) as a functionally equivalent densification process as taught by Yong ([0017]).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Hsieh and Lai, as applied to Claim 1, further in view of Drewes (US 2003/0228710 A1).
Re Claim 5, Hsieh and Lai teach the method according to Claim 1, but they do not explicitly disclose wherein performing the densification process comprises performing an anneal process on the semiconductor nitride layer (Hsieh: 50).
However, Drewes teaches a method (FIG. 4; [0067]) comprising wherein performing the densification process comprises performing an anneal process on the semiconductor nitride layer (“second nitride junction layer”; [0040] for SiN, [0067]).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method as discussed for Claim 1 with the limitations taught by Drewes to utilize a plasma anneal for densifying the semiconductor nitride layer (Hsieh: 50) as a functionally equivalent densification process as taught by Drewes ([0067]).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Hsieh and Lai, as applied to Claim 1, further in view of Farmer et al (US 2016/0307797 A1, hereafter Farmer).
Re Claim 6, Hsieh and Lai teach the method according to Claim 1, while they do not explicitly disclose:
depositing a metal nitride layer on the densified semiconductor nitride layer (Hsieh: 53); and
performing an other densification process on the metal nitride layer.
However, Farmer teaches a method (FIG. 6; [0041]), comprising:
depositing a metal nitride layer (648; [0041]); and
performing an other densification process ([0025]) on the metal nitride layer (648; [0025]).
Farmer does not explicitly disclose the metal nitride layer (Farmer: 648) is on a densified semiconductor nitride layer, but Farmer teaches formation of a contact plug with a metal nitride barrier layer (Farmer: 648). Thus, in combination with Hsieh and Lai and the use of Farmer’s contact plug (Farmer: 648 and contact material), the densified metal nitride barrier layer (Farmer: 648) would be “on” top of the densified semiconductor nitride layer (Hsieh: 53).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method as discussed for Claim 1 with the limitations taught by Farmer to utilize a densified metal nitride layer (Farmer: 648) with the contact plug (Hsieh: 70) to act as a barrier layer to protect underlying material from attack by precursors or other compounds in the processing environment as taught by Farmer ([0002]).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Hsieh and Lai, as applied to Claim 7, further in view of Chen et al (US 20210090948 A1, hereafter Chen).
Re Claim 8, Hsieh and Lai teach the method according to Claim 7, but they do not explicitly disclose performing a nitridation process on the second metal portion (Lai: 62, sidewalls portion that does not convert to silicide 66).
However, Chen teaches a method (FIGS. 14-15; [0035]-[0036]) comprising performing a nitridation process on the second metal portion (82, sidewalls; [0036]).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method as discussed for Claim 7 with the limitations taught by Chen to convert the remaining metal layer into a metal nitride layer (Chen: 84) as a part of a processing step in utilizing the metal nitride layers as a base for selectively depositing a metal as taught by Chen ([0010]).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Hsieh and Lai, as applied to Claim 1, further in view of Colombeau et al (US 2020/0161171 A1, hereafter Colombeau).
Re Claim 10, Hsieh and Lai teach the method according to Claim 1, but they do not explicitly disclose wherein performing the densification process comprises performing a plasma treatment and an ultra-violet (UV) treatment, or a plasma treatment and a thermal treatment on the semiconductor nitride layer (Hsieh: 50).
However, Colombeau teaches a method (FIG. 4; [0074]) comprising wherein performing the densification process comprises performing a plasma treatment and an ultra-violet (UV) treatment, or a plasma treatment and a thermal treatment on the semiconductor nitride layer ([0074], plasma process + intentionally holding substrate to temperature of 350 to 500 degrees Celsius).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method as discussed for Claim 1 with the limitations taught by Colombeau to utilize a plasma treatment and thermal treatment for densifying the semiconductor nitride layer (Hsieh: 50) as a functionally equivalent densification process as taught by Colombeau ([0074]).
Claims 21 and 24 are rejected under 35 U.S.C. 103 as being unpatentable over Yu et al (US 20220165856 A1, hereafter Yu) in view of Lai.
Claim 21, Yu discloses a method (FIGS. 4A-15; [0017]-[0032]), comprising:
epitaxially growing a source/drain (S/D) region (226S; [0017]) on a substrate (202; [0017]);
forming a contact structure, comprising:
depositing a semiconductor nitride layer (260; [0023], for example, silicon nitride) on a sidewall of a contact opening (272; [0031]) on the S/D region (226S; [0031]);
forming a metal nitride layer (284; [0032], for example, zirconium nitride) on the semiconductor nitride layer (260; [0032]);
forming a silicide layer (282; [0032]) on the S/D region (226S; [0032]) and the metal nitride layer (284; [0032]); and
depositing a contact plug (280; [0032]) on the silicide layer (282; [0032]); and
forming a via structure in the contact plug and in contact with a portion of the metal nitride layer.
Yu does not explicitly disclose forming a via structure in the contact plug (280) and in contact with a portion of the metal nitride layer (284).
However, Lai teaches a method (FIG. 14; pg. 6, para. 7) comprising forming a via structure (80; pg. 6, para. 7) in the contact plug (68; pg. 6, para. 7) and in contact with a portion of the metal nitride layer (64; pg. 5, para. 5).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the limitations disclosed by Yu with the limitations taught by Lai to form a via structure in the contact plug (Yu: 280) to establish source/drain contact through subsequent processing layers as taught by Lai (pg. 7, para. 5).
Re Claim 24, Yu and Lai teach the method according to Claim 21, while Yu further teaches wherein forming the silicide layer (282) comprises depositing a metal layer having a metal that is same as a metal of the metal nitride layer (284; [0033], for example, zirconium).
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Yu and Lai, as applied to Claim 21, further in view of Chen.
Re Claim 22, Yu and Lai teach the method according to Claim 21, but they do not explicitly disclose wherein forming the metal nitride layer comprises:
depositing a metal layer on the semiconductor nitride layer (Yu: 260); and
performing a nitridation process on the metal layer to form the metal nitride layer (Yu: 284) on the semiconductor nitride layer (Yu: 260).
However, Chen teaches a method (FIGS. 14-15; [0035]-[0036]) wherein forming the metal nitride layer (84; [0036]) comprises:
depositing a metal layer (82; [0035]) on the semiconductor nitride layer (80; [0035]); and
performing a nitridation process on the metal layer (82; [0036]) to form the metal nitride layer (84; [0036]) on the semiconductor nitride layer (80; [0036]).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method as discussed for Claim 21 with the limitations taught by Chen to convert a metal layer (Chen: 82) into a metal nitride layer (Chen: 84) as a part of a simplified processing step in forming both the silicide layer (Yu: 282) and the metal nitride layer (Chen: 84) from a single metal base layer (Chen: 82) as taught by Chen ([0036]).
Claim 23 is rejected under 35 U.S.C. 103 as being unpatentable over Yu and Lai, as applied to Claim 21, further in view of Chen et al (US 2021/0384345 A1, hereafter Chen-Fu).
Re Claim 23, Yu and Lai teach the method according to Claim 21, but they do not explicitly disclose implanting germanium atoms in the S/D region prior to forming the metal nitride layer (Yu: 284).
However, Chen-Fu teaches a method (FIG. 2; [0079]) comprising implanting germanium atoms in the S/D region (5; [0079]).
Chen-Fu does not explicitly disclose implanting the germanium atoms in the S/D region (Chen-Fu: 5) specifically prior to forming the metal nitride layer, but in combination Chen-Fu is substituting in the dopant to create the n-type source region (Yu: 226S), which is formed prior to the metal nitride layer (Yu: 284).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method as discussed for Claim 21 with the limitations taught by Chen-Fu to use germanium as the dopant for the n-type source region (Yu: 226S) as a functionally equivalent n-type dopant as taught by Chen-Fu ([0079]).
Allowable Subject Matter
Claims 11-16 are allowed.
Claim 9 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.
The following is a statement of reasons for the indication of allowable subject matter:
Re Claim 9, the prior art cannot anticipate, or render obvious, the limitations of: performing an other densification process on the second metal portion, in combination with the additionally claimed features of Claim 9.
Re Claim 11, the prior art cannot anticipate, or render obvious, the limitations of: performing a densification process on the metal nitride layer to form a densified metal nitride layer and a densified semiconductor nitride layer, in combination with the additionally claimed features of Claim 11.
In Re Claims 12-16, they are allowable due to their dependence from Claim 11.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to COLIN RUSSELL MCCUTCHEON whose telephone number is (703)756-1897. The examiner can normally be reached Monday-Friday, 12:30-9:30 EST.
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/COLIN RUSSELL MCCUTCHEON/Examiner, Art Unit 2892
/NORMAN D RICHARDS/Supervisory Patent Examiner, Art Unit 2892