DETAILED ACTION
This Office action responds to Applicant’s election filed on 12/05/2025.
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 is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for a 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.
Amendment Status
The Applicant’s response on 12/05/2025 in reply to the restriction mailed on 10/06/2025 has been entered. The present Office action is made with all previously suggested amendments being fully considered. Accordingly, pending in this Office action are claims 1-20.
Election/Restriction
The Applicant’s response on 12/05/2025 in reply to the restriction/election requirements mailed on 10/06/2025 has been entered. Applicant’s election without traverse of Group I (drawn to a microelectronic structure, drawn to claims 1-19, is acknowledged. Claim 20 is withdrawn by corresponding to a non-elected invention.
Information Disclosure Statement (IDS)
Acknowledgement is made of Applicant’s Information Disclosure Statement (IDS) form PTO-1449. The IDSes have been considered.
Specification Objection
The specification has been checked to the extend necessary to determine the presence of possible minor errors. For example, in par. [0056] of the specification of the instant application, the sentence of “Figures 11 and 13 illustrate that the source/drain 130 is gouge …” should be changed with “Figures 11 and 13 illustrate that the source/drain 130 is gouged …” or with “Figures 11 and 13 illustrate that the source/drain 130 has a gouged structure …”. However, the Applicant’s cooperation is requested in correcting any errors of which Applicant may become aware in the specification.
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.
Claims 1, 3, 5-6, and 12 are rejected under 35 U.S.C. 112(b) as being indefinite.
The claim is indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint regard as the invention.
Claim 1 (and any dependents) recites the limitation " and a backside contact that wraps around the trench epi and is in contact with a backside surface of the first source/drain”. The claim previously defines “a backside surface of the first source/drain” in the claim’s limitation of “a trench epi extending from a backside surface of the first source/drain”. It is not clear if “a backside surface of the first source/drain” is the same or is different in those two different limitations of claim 1. Also, there is insufficient antecedent basis for the limitation of “a backside surface of the first source/drain”. Thus, the limitation of " and a backside contact that wraps around the trench epi and is in contact with a backside surface of the first source/drain” should be written as " and “a backside contact that wraps around the trench epi and is in contact with the backside surface of the first source/drain”.
Claim 3 (and any dependents) also recites the limitation "… towards the backside of the nanosheet transistor”. There is insufficient antecedent basis for the limitation of "… towards the backside of the nanosheet transistor”. Thus, the limitation of "… towards the backside of the nanosheet transistor” should be written as "… towards the backside of a nanosheet transistor”.
Claims 5 and 12 (and any dependents) also recites the limitation "… wherein the backside contact is contact with the tip of the trench epi”. This limitation should be corrected with the limitation of “… wherein the backside contact is contact with the tip of the trench epi”.
Claim 6 (and any dependents) also recites the limitation "… wherein the backside contact is in contact with the curved backside surface of the first source/drain”. There is insufficient antecedent basis for the limitation of "… wherein the backside contact is in contact with the curved backside surface of the first source/drain”. Thus, the limitation of "… wherein the backside contact is in contact with the curved backside surface of the first source/drain” should be written as "… wherein the backside contact is in contact with a curved backside surface of the first source/drain”.
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.
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 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Bao (US 2018/0337277) in view of Cheng (US 2020/0403099).
Regarding claim 1, Bao shows (see, e.g., Bao: fig. 14 and annotated fig. 14) all aspects of the instant invention including semiconductor package 500, comprising:
A transistor 300 (see, e.g., Bao: par. [0003], and [0055]) that includes a first source/drain and a second source/drain
A trench epi 900 extending from a backside surface of the first source/drain
A backside contact 902 that wraps around the trench epi 900 and is in contact with a backside surface of the first source/drain
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However, Bao fails (see, e.g., Bao: fig. 14 and annotated fig. 14) to show that the transistor 300 is a nanosheet transistor. Cheng, in a similar device to Bao, shows (see, e.g., Cheng: fig. 11) the transistor is a nanosheet transistor (see, e.g., Cheng: par. [0034]). Cheng further shows that the nanosheet transistor comprises nanosheets, which offer improved electrostatics and higher current density per footprint area than FinFETs (see, e.g., Cheng: par. [0001]).
It would have been obvious at the time of filing the invention to one of ordinary skill in the art to include the nanosheet transistor of Cheng in the device of Bao, in order to offer improved electrostatics and higher current density per footprint area than FinFETs.
Regarding claim 7, Bao in view of Cheng shows (see, e.g., Bao: fig. 14 and annotated fig. 14) that a first portion of a sidewall of the backside contact 902 is in contact with a liner (see, e.g., Bao: par. [0055], element liner is not shown in the fig. 14).
Claims 2-6 are rejected under 35 U.S.C. 103 as being unpatentable over Bao in view of Cheng in further view of Xie (US 2019/0081145).
Regarding claim 2, Bao in view of Cheng shows (see, e.g., Bao: fig. 14 and annotated fig. 14) most aspects of the instant invention including a microelectronic structure 300, comprising a first source/drain.
However, Bao in view of Cheng fails (see, e.g., Bao: fig. 14 and annotated fig. 14) to show that the backside surface of the first source/drain is curved from a gouging process. Xie, in a similar device to Bao in view of Cheng, shows (see, e.g., Xie: fig. 9B) that the backside surface 208 of the first source/drain 128 is curved from a gouging process (see, e.g., Xie: par. [0077]). Xie also shows (see, e.g., Xie: fig. 9B) that, when forming a contact structure to the source/drain regions of a PFET, it is desirable to only slightly gouge into the source/drain region in order to prevent damage to the epi stressor and preserve the compressive stress in the channel of the PFET. Slightly gouging the source/drain region of the PFET increases the interface area between the contact structure and the source/drain region, thus reducing the resistance at the interface (see, e.g., Xie: par. [0006]).
It would have been obvious at the time of filing the invention to one of ordinary skill in the art to include the backside surface of the first source/drain of Xie, curved from a gouging process, in the device of Bao in view of Cheng, in order to prevent damage to the epi stressor and preserve the compressive stress in the channel, and to increase the interface area between the contact structure and the source/drain region, thus reducing the resistance at the interface.
Regarding claim 3, Bao in view of Cheng in view of Xie shows (see, e.g., Bao: fig. 14 and annotated fig. 14) that the trench epi 900 includes a tip pointing towards the backside of the nanosheet transistor 300.
Regarding claim 4, Bao in view of Cheng in view of Xie shows (see, e.g., Bao: fig. 14 and annotated fig. 14) that the backside contact 902 is in contact with the sidewalls of the trench epi 900.
Regarding claim 5, Bao in view of Cheng in view of Xie shows (see, e.g., Bao: fig. 14 and annotated fig. 14) that the backside contact 902 is contact with the tip of the trench epi 900.
Regarding claim 6, Bao in view of Cheng in view of Xie shows (see, e.g., Xie: fig. 9B) that the backside contact 176 is in contact with the curved backside surface 208 of the first source/drain 128.
Allowable Subject Matter
Claims 10-19 are allowed.
Claims 8-9 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.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TIBERIU DAN ONUTA whose telephone number is (571) 270-0074 and between the hours of 9:00 AM to 5:00 PM (Eastern Standard Time) Monday through Friday or by e-mail via Tiberiu.Onuta@uspto.gov. If attempts to reach the examiner by telephone or email are unsuccessful, the examiner's supervisor, Wael Fahmy, can be reached on (571) 272-1705.
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/TIBERIU DAN ONUTA/Examiner, Art Unit 2814
/WAEL M FAHMY/Supervisory Patent Examiner, Art Unit 2814