DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 102
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.
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.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim 1 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Hafez (U.S. PGPub 2021/0183857).
Regarding claim 1, Hafez teaches a method comprising:
forming a first gate opening in a first device region and a second gate opening in a second device region, wherein first semiconductor layers are suspended over a substrate in the first gate opening in the first device region and second semiconductor layers are suspended over the substrate in the second gate opening in the second device region (Fig. 4A, first device region 472p, second device region 472n, first semiconductor layers 410p, second semiconductor layers 410n, [0059]-[0060]),
forming metal oxide layers over the first semiconductor layers and the second semiconductor layers, wherein the metal oxide layers partially fill the first gate opening and the second gate opening and wherein each of the first semiconductor layers and each of the second semiconductor layers has a respective one of the metal oxide layers disposed thereover (same metal oxide layers 412p/n, [0060]),
after forming a nitrogen-blocking mask over the metal oxide layers over the second semiconductor layers, performing a first nitrogen thermal treatment (Fig. 4B, mask 450, [0061]),
after removing the nitrogen-blocking mask from over the metal oxide layers over the second semiconductor layers, performing a second nitrogen thermal treatment, wherein the second nitrogen thermal treatment is different than the first nitrogen thermal treatment (Fig. 4C, [0062]), and
after performing the second nitrogen thermal treatment, forming a first metal layer that fills a remainder of the first gate opening and a second metal layer that fills a remainder of the second gate opening, wherein the first metal layer is formed in the first gate opening over the metal oxide layers over the first semiconductor layers and the second metal layer is formed in the second gate opening over the metal oxide layers over the second semiconductor layers (Fig. 4D, metal layers 430, [0064]).
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 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 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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
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.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Hafez (U.S. PGPub 2021/0183857) in view of Chan (U.S. PGPub 2022/0262928).
Regarding claim 7, Hafez teaches wherein the first nitrogen thermal treatment is a first anneal process performed in a first ambient that includes NH3 ([0061]) and the second nitrogen thermal treatment is a second anneal process performed in a second nitrogen ambient ([0062]) but does not explicitly teach wherein the first and second ambients include N2.
Chan teaches wherein nitrogen anneal processes for gate dielectrics may include NH3 or N2 ([0031]).
Therefore it would have been obvious to a person having ordinary skill in the art before the time of the effective filing date to combine the teachings of Chan with Hafez such that the first and second ambients include N2 because the prior art teaches every element, a person of ordinary skill could have combined them as claimed and in combination each element performs the same function as it does separately, and the combination would have yielded predictable results to one of ordinary skill in the art before the time of the invention. See MPEP 2143(I)A.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Hafez (U.S. PGPub 2021/0183857) in view of Thomas (U.S. PGPub 2022/0199620).
Regarding claim 8, Hafez teaches wherein the forming the nitrogen-blocking mask includes:
depositing a mask over the metal oxide layers over the first semiconductor layers and over the metal oxide layers over the second semiconductor layers and removing the mask from over the metal oxide layers over the first semiconductor layers ([0061]-[0062]).
Hafez does not explicitly teach wherein the nitrogen-blocking mask is a metal oxide mask. Hafez is silent on the material of the nitrogen-blocking mask.
Thomas teaches wherein a blocking mask formed over stacked semiconductor channels may be formed of a metal oxide ([0055]).
Therefore it would have been obvious to a person having ordinary skill in the art before the time of the effective filing date to combine the teachings of Thomas with Hafez such that the nitrogen-blocking mask is a metal oxide mask because the prior art teaches every element, a person of ordinary skill could have combined them as claimed and in combination each element performs the same function as it does separately, and the combination would have yielded predictable results to one of ordinary skill in the art before the time of the invention. See MPEP 2143(I)A.
Allowable Subject Matter
Claims 9-20 are allowed.
Claims 2-6 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 dependent claim 2 and independent claims 9 and 15, the prior art, alone or in combination, does not explicitly teach the required method steps comprising first and second stacks with a plurality of semiconductor layers, wherein two top or bottom semiconductor layers have metal oxide layers formed over the gate dielectric, the first or second stack is masked, and then a nitrogen annealing process is performed (elements common to these claims). Prior art teaches masking and annealing lower or upper semiconductor layers of a single stack (U.S. PGPub 2023/0198828), other methods for multiple stacks (U.S. PGPub 2022/0416048, U.S. PGPub 2022/0375935, U.S. PGPub 2021/0366783, U.S. PGPub 2021/0013326) and for adjacent stacks not separated (U.S. PGPub 2022/0199472). Dependent claims 2-6, 10-14, and 16-20 respectively depend from and further limit claims 2, 9, and 15 and are therefore correspondingly allowable. Prior art references alone or in combination fail to disclose, teach, or suggest each and every limitation of the invention as claimed.
Conclusion
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/ALIA SABUR/Primary Examiner, Art Unit 2812
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