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 .
Claim Rejections - 35 USC § 102
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.
Claim(s) 15 & 19 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Pillarisetty (US Pub no. 2011/0156005 A1).
Regarding claim 15, Pillarisetty et al discloses a method comprising: epitaxially growing a channel stack (404/406/408/410/411/412/414)over a substrate(402) [0070][0062-0063][0067], wherein the channel stack(404/406/408/410/411/412/414) is a
heterostructure and comprises: a channel layer(408) comprising a first metal-containing binary compound material(SiGe)regions 458 to 460) fig. 17/fig 18[0073]; and a barrier layer (410)in contact with the channel layer (408)and comprising a second metal- containing binary compound material(SiGe)(460-462) [0073], wherein the first metal-containing binary compound material and the second metal-containing binary compound material comprise the same chemical elements(fig. 17/fig. 18)[0073], and a metal atomic percentage of the first metal- containing binary compound material is higher than a metal atomic percentage of the second metal-containing binary compound material(fig. 17-fig. 18)[0073]; forming source/drain electrodes(420/422) over the substrate (402)and in contact with the channel layer(408); depositing a gate dielectric layer(416) to cover the channel stack; and forming a gate electrode(418) over the gate dielectric layer(416) and the channel stack(404/406/408/410/411/412/414)(fig. 12a.
Regarding claim 19, Pillarisetty et al discloses wherein the channel stack (404/406/408/410/411/412/414)further comprises a buffer layer (404)under the channel layer (408)and comprising a third metal-containing binary compound material, wherein the metal atomic percentage of the first metal-containing binary compound material is higher than a metal atomic percentage of the third metal-containing binary compound
material fig. 17/fig. 18 [0073].
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.
Claim(s) 1-4 & 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ma (US Pub no. 2014/0197376 A1) in view of Nakayama (US Pub no. 2018/0040726 A1)
Regarding claim 1, Ma et al discloses a method comprising: epitaxially growing a Ge1-x Snx channel layer (5) over a substrate(1)[0023][0027] ; epitaxially growing a Ge1-ySny barrier layer(6)([0035- states SiGeSn can be used) over the Ge1-xSnx channel layer(5) to form a two-dimensional hole gas in the Ge1-xSnx channel layer(5) [0028][0035]; etching the Ge1-xSnx channel layer(5) and the Ge1-ySny barrier layer(6) to form a first opening and a second opening in the Ge1-xSnx channel layer(5) and the Ge1-ySny barrier layer(6)[0032] and forming a first gate electrode (7/7b)over the Ge1-ySny barrier layer(6)[0029][0035] fig. 1.
Ma et al teaches the Ge1-xSnx channel layer(5)[0027] but is silent to “in a metastable state” . Since Ma et al teaches the same or similar composition as applicant’s invention [Applicant’s specification-0025] , a prima facie case of anticipation or obviousness exists that the Ge1-xSnx channel layer in Ma et al would necessarily possess the characteristics of “metastable state, In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433-34 (CCPA 1977). Furthermore, Ma et al fails to teach depositing a first source/drain electrode and a second source/drain electrode in the first opening and the second opening, respectively.
Nakayama et al discloses a field effect transistor comprising a source electrode(105) and drain electrode(106) in the first opening and the second opening formed in the channel (102)and barrier layer(103) [0098]. Since depositing first source/drain electrode and a second source/drain electrode in first and second openings is one of finite solutions to improve ohmic contact resistance as taught by Nakayama et al, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to try in Ma et al because a person of ordinary skill has good reason to pursue the known options within his or her technical grasp. If this leads to the anticipated success, it is likely the product not of innovation but of ordinary skill and common sense (KSR International Co. v. Teleflex Inc., 82 USPQ2d 1385 (U.S. 2007))
Regarding claim 2, Ma et al discloses x [0027] and y[0028][0031][0035] but fails teach wherein x > y. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to adjust the concentration of x and y such that x>y is achieved through routine experimentation to optimize carrier mobility. [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)
Regarding claim 3, Ma et al discloses wherein 0 < x < 30%[0027].
Regarding claim 4, Ma et al discloses wherein the Ge1-ySny barrier layer 6[0028][0031][0035] but is silent to “in a metastable state” . Since Ma et al teaches the same or similar composition(Ma et al teaches cap 6 can be the same material as element 8 (SiGeSn)[0028][0031][0035] as applicant’s invention [Applicant’s specification-0025] , a prima facie case of anticipation or obviousness exists that the Ge1-xSnx channel layer in Ma et al would necessarily possess the characteristics of “metastable state”. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433-34 (CCPA 1977).
Regarding claim 6, Ma et al discloses further comprising: further comprising: epitaxially growing a Ge1-zSnz, buffer layer(2) over the substrate[0023-0024], and the Ge1-xSnx channel layer(5) is epitaxially grown and in contact with the Ge1-zSnzbuffer layer[0025]0027] (Examiner notes the buffer layer is in contact with the channel layer by way of element 4[0023-0027]). Ma et al fails to teach wherein x>z. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to adjust the concentration of x and z such that x>z is achieved through routine experimentation to optimize carrier mobility. [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)
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ma (US Pub no. 2014/0197376 A1) in view Nakayama (US Pub no. 2018/0040726 A1) as applied to claim 1 and further in view of Sriram (US Pub no. 2014/0361343 A1).
Regarding claim 5, Ma et al as modified by Nakayama et al discloses all the claim limitations of claim 1 but fails to teach further comprising forming a second gate electrode over the Ge1-ySny barrier layer, wherein the second gate electrode is between the first gate electrode and the first source/drain electrode.
However, Sriram et al teaches a transistor device comprising forming a second gate electrode (48)over the barrier layer(38) wherein the second gate electrode (48)is between a first gate electrode(46) and first source/drain electrode(42,44)[0086]. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Ma et al and Nakayama et al with the teachings of Siriram et al such that forming a second gate electrode over the Ge1-ySny barrier layer, wherein the second gate electrode is between the first gate electrode and the first source/drain electrode results since adding a second gate acts as a shield for the first gate and reduces the feedback capacitance between the drain and first gate.
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ma (US Pub no. 2014/0197376 A1) in view Nakayama (US Pub no. 2018/0040726 A1) as applied to claim 6 and further in view of Moutanabbir (US Pub no. 2022/0310793 A1).
Regarding claim 7, Ma et al as modified by Nakayama et al discloses all the claim limitations of claim 6 but fails to teach wherein a Sn atomic percentage of the Ge1-zSnz buffer layer is decreased in a depth direction of the Ge1-zSnz buffer layer.
However, Moutanabbir et al discloses a quantum well structure wherein a Sn atomic percentage of the Ge1-zSnz buffer layer is decreased in a depth direction of the Ge1-zSnz buffer layer[0175]. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Ma et al and Nakayama et al with the teachings of Moutanabbir et al to facilitate the incorporation of Sn in the growing layer.
Claim(s) 16 & 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pillarisetty (US Pub no. 2011/0156005 A1).
Regarding claim 16, Pillarisetty et al discloses all the claim limitations of claim 15 and further teaches wherein the metal atomic percentage of the first metal-containing binary compound material[0073] but fails to teach is not higher than about 30%. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to achieve an atomic percentage not higher than about 30% through routine experimentation to optimize lattice mismatch. [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)
Regarding claim 17, Pillarisetty et al discloses wherein the metal atomic percentage of the second metal-containing binary compound material [0073] is not higher than about 30%. but fails to teach is not higher than about 30%. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to achieve an atomic percentage not higher than about 30% through routine experimentation to optimize lattice mismatch. [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)
Allowable Subject Matter
Claims 8-14 & 21 are allowed.
The following is a statement of reasons for the indication of allowable subject matter: wherein the first Sn atomic percentage of the channel layer is greater than the second Sn atomic percentage of the barrier layer was not found in prior art.
Claims 18 & 20 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.
Response to Arguments
Applicant's arguments filed 3/23/2026 have been fully considered but they are not persuasive. With regards to claim 1, applicant argues that Ma et al discloses the cap layer 6 at least includes Si and Ge. Therefore, even the cap layer 6 includes y atomic percent of Sn, the atomic percent of Ge in the cap layer 6 would not be 1-y as claimed.
Examiner notes that claim 1 lacks explicit constraints for “y “ and the term “comprising” allows for ternary structures. The transitional term “comprising” which is synonymous with "including," "containing," or "characterized by," is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. See, e.g., Mars Inc. v. H.J. Heinz Co., 377 F.3d 1369, 1376, 71 USPQ2d 1837, 1843 (Fed. Cir. 2004) . Given that the reference Ma et al discloses that the cap layer can be formed of SiGeSn [0035] the claim limitation has been met and therefore the rejection of claim 1 is maintained.
Applicant’s arguments with respect to claim(s) 8-20 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to LATANYA N CRAWFORD EASON whose telephone number is (571)270-3208. The examiner can normally be reached Monday-Friday 8:30 AM-4:30 PM.
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/LATANYA N CRAWFORD EASON/Primary Examiner, Art Unit 2813
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