DETAILED ACTION
Claims 1-9 and 11-21 are pending before the Office for review.
In the response filed February 10, 2026:
Claims 1 was amended.
Claim 10 was canceled.
No new matter is present.
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
Claims 16-21 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim.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 October 13, 2025.
Applicant's election with traverse of Group I claims 1-15 in the reply filed on October 13, 2025 is acknowledged. The traversal is on the ground(s) that the groups are not patentable distinct inventions. It is Applicant’s position that the claimed method and apparatus share common structural and functional features and are not distinct in terms of inventive concept. It is Applicant’s position that when an apparatus is disclosed solely or carrying out a claimed method, and the apparatus claims do not include additional features rendering them patentably distinct from the method, unity of invention exists, and restriction is improper. This is not found persuasive because it is the Examiner’s position that Applicant’s apparatus not specifically adapted for Applicant’s method. In addition, Applicant’s claimed apparatus can be used to practice another materially different process. Process and apparatus for its practice can be shown to be distinct inventions, if either or both of the following can be shown: (A) that the process as claimed can be practiced by another materially different apparatus or by hand; or (B) that the apparatus as claimed can be used to practice another materially different process. MPEP 806.05(e) In addition, searching both groups would be a serious search and examination burden on the Examiner as the claims have separate and distinct classification; require addition fields of search which do not overlap and are not mere variations of each other.
The requirement is still deemed proper and is therefore made FINAL.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-7 and 10-16 are rejected under 35 U.S.C. 103 as being unpatentable over ZHANG et al (U.S. Patent Application Publication 2015/0372118) in view of LIU et al (U.S. Patent Application Publication 2022/0367625).
With regards to claim 1, Zhang discloses a method for fabrication of a semiconductor structure, which comprises: providing a semiconductor structure which includes a plurality of first layers and a plurality of second layers (504a, 504b), wherein each of the first layers lies parallelly on each of the second layers and the first layer comprises a first material and the second layer comprises a second material (Figure 5A Paragraphs [0061]-[0065]); performing a first etching process in a first direction (etching 516) onto a surface of the semiconductor structure to form a plurality of fin structures with sidewall surfaces of the first material and the second material (Figure 5B Paragraphs [0069]-[0073]); and performing a second etching process onto the sidewall surfaces to remove the second layers and form a plurality of voids, wherein the second etching process has an etching selectivity between the first material and the second material (Figure 5C1 Paragraphs [0074]-[0077]) and wherein the second etching process is performed by radical species.(Paragraphs [0072], [0077] discloses generating a plasma).
Zhang does not explicitly disclose performing a first etching process by irradiating neutral beam in a first direction onto a surface of the semiconductor structure to form a plurality of fin structures with sidewall surfaces of the first material and the second material.
Liu discloses a method of fabrication of a semiconductor structure which comprises; providing a semiconductor structure which includes a plurality of first layer and second layer (Figure 2 layers 56 and 54) performing a first etching process by an anisotropic etching by reactive ion etching, neutral beam etching or the like or combinations thereof (Figure 3 Paragraphs [0021]-[0028]) rendering obvious irradiating neutral beam in a first direction onto a surface of the semiconductor structure to form a plurality of fin structures (62) with sidewall surfaces of the first material and the second material (Figure 3) and performing a lateral etching process to form sidewall recess (Paragraph [0046] Figure 9A).
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 Zhang to include the neutral beam etching of Liu because one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictably achieving the desired etching using the neutral beam etching as rendered obvious by Liu. MPEP 2143D
With regards to claim 2, the modified teachings of Zhang renders obvious wherein the first material is silicon.(Zhang Paragraph [0077] layer 504b)
With regards to claim 3, the modified teachings of Zhang renders obvious wherein the second material comprises germanium. (Zhang Paragraph [0077] layer 504a).
With regards to claim 4, the modified teachings of Zhang discloses wherein layer 504b comprise epi-SI and wherein layer 504a comprises SiGe wherein the SiGe layer is selectively etch relative to Si (Zhang Paragraphs [0064]-[0065], [0077])) which renders obvious wherein the higher content of germanium in the second material, the better etching selectivity between the first material and the second material, wherein the content of germanium contained in the second material is in a range between more than 0% and 50.
With regards to claim 5, the modified teachings of Zhang renders obvious wherein the second material is silicon germanium. (Zhang Paragraph [0077]
With regards to claim 6, the modified teachings of Zhang renders obvious wherein the first direction is substantially vertical to the surface of the semiconductor structure to form the fin structures, wherein the sidewall surfaces are substantially parallel to the first direction. (Zhang Figure 5B Paragraphs [0066, [0069] discloses forming an opening have a predetermined width wherein the opening in the pattern is transferred into the opening 516 in the layers wherein etching is conducted until the desired depth is reached).
With regards to claim 7, the modified teachings of Zhang renders obvious wherein the second etching process is performed in a second direction to form the voids, wherein the second direction is substantially vertical to the first direction.(Zhang Paragraphs [0074]-[0077] discloses performing lateral etching to remove or substantially remove a layer of material).
With regards to claim 11, the modified teachings of Zhang discloses wherein a lateral etching process is performed to selectively remove or partial remove one type of material from the substrate (Zhang Paragraph [0074]). Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) MPEP 2144.05(II)(A) Therefore 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 optimize the etching rate to amount including an etching rate of the second layer that is at least 10 times greater than an etching rare of the first layers in order to remove or partial selectively remove one type of material from the substrate as taught by the modified teachings of Zhang (Zhang Paragraph [0074], MPEP 2144.05(II)(A)).
With regards to claim 12, the modified teachings of Zhang renders obvious wherein the etching rate of the second layers is controlled by varying a parameter value which is at least one selected from a group consisting of a content of germanium contained in the second material, a kind of the radical species, a flowing rate of the radical species, and a temperature of the fin structures. (Zhang Paragraphs [0074]-[0078] discloses selectively between layers can be adjust during the lateral etch by providing a germanium containing material; suitable precursor gases which are used to generate the plasma; flow rate ratio between gases; temperature during lateral etching process).
With regards to claim 13, the modified teachings of Zhang renders obvious wherein the radical species comprise oxygen radical, nitrogen radical, fluorine radical, chlorine radical and hydrogen radical. (Zhang Paragraph [0077]).
With regards to claim 14, the modified teachings of Zhang renders obvious wherein a second composition of gas in which the fluorine radical is generated is at least one selected from a group consisting of NF3.(Liu Paragraph [0054]).
With regards to claim 15, the modified teachings of Zhang renders obvious wherein the first etching process is an anisotropic etching (Liu Paragraph [0028]), and the second etching process is an isotropic etching.(Paragraph [0046])
Claims 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over ZHANG et al (U.S. Patent Application Publication 2015/0372118) in view of LIU et al (U.S. Patent Application Publication 2022/0367625), as applied to claims 1-7 and 11-16, in further view of LEE et al (Defect-free Germanium Etching for 3D Fin MOSFET using Neutral Beam Etching).
With regards to claims 8-9, the modified teachings of Zhang renders obvious Applicant’s claim 1.
However the cited prior art does not explicitly disclose wherein an acceleration energy of the neutral beam performed onto the surface of the semiconductor structure is controlled by a radio frequency electric field in a range between 400 kHz and 800 kHz wherein the neutral beam is generated in a first composition of gas, wherein the first composition of gas comprises halogen.
Lee discloses a method of processing a semiconductor substrate comprising etching a fin structure comprising etching a germanium containing fin structure with a neutral beam at a radio frequency of 600 kHz (Page 816) using a composition gas comprising chloride (Pages 816-817) which renders obvious wherein an acceleration energy of the neutral beam performed onto the surface of the semiconductor structure is controlled by a radio frequency electric field in a range between 400 kHz and 800 kHz wherein the neutral beam is generated in a first composition of gas, wherein the first composition of gas comprises halogen. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). MPEP 2144.05
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 further modify the modified method of Zhang to include the neutral beam etching of Lee because one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictably achieving the desired etching using the neutral beam etching as rendered obvious by Lee. MPEP 2143D
Response to Arguments
Applicant's arguments filed February 10, 2026 have been fully considered but they are not persuasive.
Applicant argues on pages 6-9 of Applicant’s response that the cited prior art fails to teach or render obvious Applicant’s independent claim 1 including “… the second etching process is performed by a radical species.” Applicant argues that Zhang performs a conventional plasma process followed by a subsequent lateral etching that must rely on a chemical wet etching or a standard gas phase etching that tolerates the roughness from the first plasma process. Applicant argues that the combination of Zhang and Liu fails to render amended claim 1 obvious because neither reference teaches or suggests the second step of "a radical species" etching in combination with the defect-free surface of the first step.
In addition there is no suggestion or modification to substitute the RIE in Zhang with the RIE from Liu as suggested would lead to Applicant’ claimed invention requires the radical species but would result in a hybrid method of NBE and wet etching. In addition, Applicant argues that the Examiner is using hindsight reasoning to cherry pick and formulate Applicant’s claimed invention. Applicant argues that Lee is directed to solving surface defects specifically in Germanium(Ge) fins. A person seeking to optimize the stack of Zhang would not have looked to a reference dedicated to germanium fins and therefore there is no reasonable expectation of success.
It is Applicant’s position that Zhang as modified by Liu and Lee fail to teach or render the obvious the limitations of claim 1 and therefore claim 1 is allowable. As to the dependent claims they are allowable based on their dependency. This is found unpersuasive.
It is the Examiner’s position that Zhang as modified by Liu renders obvious Applicant’s claimed invention including “… the second etching process is performed by a radical species.” It is the Examiner’s position that Zhang discloses performing a first etching process (Paragraphs [0069]-[0073]) and a second etching process wherein the second etching process [0074]-[0077]) wherein the second etching process supplies gas into a remote plasma source to promote plasma etching by a RF source power or a bias power or both (Paragraph [0077]). Liu discloses etching a multilayer film using any acceptable etch process including Reactive ion etch (RIE) neutral bean etch (NBE) or a combination thereof (Paragraphs [0021]-[0028]). One cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). MPEP 2145(IV) Therefore while Zhang and Liu do not individually disclose Applicant’s claimed invention, the combined reference renders obvious each of Applicant’s claimed steps.
In addition, it is the Examiner’s position that Zhang is not directed towards wet etching as a secondary step of etching, contrary Zhang discloses wherein the second etching process supplies gas into a remote plasma source to promote plasma etching by a RF source power or a bias power or both (Paragraph [0077]). Therefore the combined teachings of Zhang as modified by Liu would result in the hybrid method of NBE + plasma. In addition, although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993) MPEP 2145(VI). Applicant’s arguments that the reference do not teach to form “a defect free surface in the first step” is not persuasive as such limitation is not present in the currently amended claims.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971). It is the Examiner’s position Zhang and Liu are directed towards etching alternating layer of silicon and silicon germanium. In addition the teachings of Zhang disclose the layer may comprise a germanium containing layer including silicon germanium and a germanium layer (Paragraph [0065]) and therefore one of ordinary skill in the art would be motivated to look towards art related to germanium layer including the reference of Lee.
The Examiner maintains that Zhang as modified by Lui renders obvious the limitations of currently amended claim 1. In addition, the Examiner maintains that one would modify the teachings of Zhang in view of Liu to further include the teachings of the related art of Lee. Therefore the Examiner maintains the rejected on record. As to the remaining dependent claims they remain rejected as no separate arguments have been provided.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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.
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, Joshua Allen can be reached at 571-270-3176. 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.
/STEPHANIE P DUCLAIR/Primary Examiner, Art Unit 1713