DETAILED ACTION
Claims 1-20 are pending before the Office for review.
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 .
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.
The factual inquiries 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.
Claims 1-4 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over XIE et al (U.S. Patent Application Publication 2021/0210349) in view of ZHANG et al (U.S. Patent Application Publication 2006/0183308) and VORONIN et al (U.S. Patent Application 2020/0266070).
With regards to claim 1, Xie discloses a method for patterning comprising: having a substrate comprising a first layer (110), a second layer to-be-patterned disposed under the first layer (108), and a third layer (106) disposed under the second layer (Figure 2 Paragraphs (0031]-[000038]); the first layer comprising a plurality of lines, each of the plurality of lines being separated by a recess, a bottom of the recess exposing a surface of the second layer; laterally etching the recesses in the second layer using a second plasma (Figures 6-8 Paragraphs [0046]-[0051] discloses semiconductor structure 100; etching the openings through the nanowires 110 and nanosheet stack 106 and after etching laterally etching to remove portions of each of SiGe layers 106a and 110b to form divots).
Xie does not explicitly disclose exposing the substrate to a first plasma, the first plasma being generated from a first halogen based gas and a first oxidizing gas, the first halogen based gas comprising a carbon-containing halogen based gas; and laterally etching the recesses in the second layer using a second plasma, the second plasma being generated from a second halogen based gas and a second oxidizing gas, the second halogen based gas being a carbon-free halogen based gas.
Zhang discloses a method of etching a conductive layer comprising Si, Ge, SiGe and mixtures thereof and a multilayer structure of the same materials comprising generating a plasma comprising a mixture of at least one carbon containing gas and in the presence of a gas such as O2 wherein the carbo containing case comprises carbon containing halogen based plasma (Paragraphs [0034], [0050]-[0052] Figures 5A,B – 6A,B) which renders obvious exposing the substrate to a first plasma, the first plasma being generated from a first halogen based gas and a first oxidizing gas, the first halogen based gas comprising a carbon-containing halogen based gas.
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to modify the method of Xie to include the first plasma as rendered obvious by Zhang because the reference of Zhang teaches that such etching composition allow for the etching of the stack while protecting the sidewalls (Paragraphs [0054]-[0055]) and one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictable achieving the desired etching using the first plasma as rendered obvious by Zhang. MPEP 2143D
Voronin discloses an etching method of laterally etching Si:SiGe using a plasma comprising NF3/O3/N2 (Paragraphs [0037], [0070]) rendering obvious laterally etching the recesses in the second layer using a second plasma, the second plasma being generated from a second halogen based gas and a second oxidizing gas, the second halogen based gas being a carbon-free halogen based gas. As such Xie as modified by Zhang and Voronin render obvious exposing the substrate to a first plasma, the first plasma being generated from a first halogen based gas and a first oxidizing gas, the first halogen based gas comprising a carbon-containing halogen based gas; and laterally etching the recesses in the second layer using a second plasma, the second plasma being generated from a second halogen based gas and a second oxidizing gas, the second halogen based gas being a carbon-free halogen based gas.
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to modify the method of Xie to include the second plasma as rendered obvious by Voronin because the reference of Voronin teaches that such plasma composition advantageously provides for highly selective etching (Paragraph [0070]) and one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictable achieving the desired lateral etching using the second plasma as rendered obvious by Voronin. MPEP 2143D
With regards to claim 2, the modified teachings of Xie renders obvious wherein the first halogen based gas comprises a hydrofluorocarbon (Zhang Paragraph [0052]) and the first oxidizing gas comprises oxygen (Zhang Paragraph [0052]), and wherein the second halogen based gas comprises NF3 (Voronin Paragraph [0070]) and the second oxidizing gas comprises oxygen. (Voronin Paragraph [0070]).
With regards to claim 3, the modified teachings of Xie renders obvious wherein the first oxidizing gas and the second oxidizing gas comprise molecular oxygen (Zhang Paragraph [0050], Voronin Paragraph [0070]).
With regards to claim 4, the modified teaching of Xie renders obvious wherein the first halogen based gas and the second halogen based gas comprise fluorine atoms. (Zhang Paragraph [0050]-[0052], Voronin Paragraph [0070]).
With regards to claim 7, the modified teachings of Xie renders obvious wherein the first layer comprises a first nanosheet stack (110) and the third layer comprises a second nanosheet stack (106). (Figures 2, 6 Paragraphs [0035]-[0040, [0046])
Allowable Subject Matter
Claims 8-20 are allowed.
Claims 5-6 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: The Examiner has rejected the subject matter of independent claim 1 under Xie as modified by Zhang and Voronin. However the cited prior art fails to teach or render obvious wherein the second layer laterally etched using a second plasma is a dielectric layer. A further search of the prior art has failed to produce analogous art which teaches or renders obvious Applicant’s claimed invention.
With regards to independent claim 8, the closet prior art of record is Xie as modified by Zhang and Voronin. However the cited prior art fails to teach or render obvious “… etching through the middle layer to expose the bottom layer using a first discharge gas, the etching extending the plurality of lines from the top layer into the middle layer, wherein a first line of the plurality of lines has a top critical dimension (T-CD) having a first T-CD value and a bottom critical dimension (B-CD) having a first B-CD value, the T-CD being the width of the first line at an intersection of the top layer and the middle layer, the B-CD being the width of the first line at an intersection of the middle layer and the bottom layer; and laterally etching the middle layer using a second discharge gas different from the first discharge gas, the lateral etching changing the T-CD of the first line from the first T-CD value to a second T-CD value and the B-CD of the first line from the first B-CD value to a second B-CD value, the difference between first T-CD value and the second T-CD value being less than the difference between first B-CD value and the second B-CD value.” A further search of the prior art has failed to produce analogous art which teaches or renders obvious Applicant’s claimed invention.
With regards to independent claim 19, the closet prior art of record is Xie as modified by Zhang and Voronin. However the cited prior art fails to teach or render obvious “… measuring the width of the first line to have a first width; determining an etching time for laterally etching the middle layer based on the first width; etching through the middle layer to expose the bottom layer using a first discharge gas, the etching extending the plurality of lines from the top layer into the middle layer; and laterally etching, for an overetch time, the middle layer using a second discharge gas different from the first discharge gas.” A further search of the prior art has failed to produce analogous art which teaches or renders obvious Applicant’s claimed invention.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHANIE P. DUCLAIR whose telephone number is (571)270-5502. The examiner can normally be reached 9-6:30 M-F.
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/STEPHANIE P DUCLAIR/Primary Examiner, Art Unit 1713
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