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 § 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.
Claims 21-25, 28 and 29 are rejected under 35 U.S.C. 103 as being unpatentable over Ando et al. (US 2021/0328103) hereinafter “Ando” in view of Lee et al. (US 9,240,483) hereinafter “Lee”.
Regarding claim 21, Fig. 10B of Ando teaches a method, comprising: forming a nanostructure, of a transistor, vertically arranged above a substrate (Item 101); forming a channel structure of the nanostructure, the channel structure comprising a plurality of nanostructure channels (Items 104) over the substrate (Item 101) and extending between source/drains (Items 120) of the transistor; and forming a work function material (WFM) (Any of Items 231/234/232), that includes aluminum and carbon (Paragraph 0075 where Titanium Aluminum Carbide is used), disposed around the plurality of nanostructure channels of the channel structure and separated from the source/drains (Item 120) by one or more inner spacers (Item 111).
Ando does not explicitly teach where the WFM comprises a concentration of titanium that is in a range of greater than 0% to less than 1.5% of the WFM.
However, the concentration of titanium in a TiAlC material is a result effective variable (Lee Column 5, Lines 60-63 where the amount of Ti in a TiAlC work function material may be adjusted and Lee Column 6, Lines 54-61 where the work function of a transistor may be tuned according to the composition of a TiAlC work function material). In In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977), the CCPA held that a particular parameter must first be recognized as a result-effective variable, i.e., a variable which achieves a recognized result, before the determination of the optimum or workable ranges of said variable might be characterized as routine experimentation, because "obvious to try" is not a valid rationale for an obviousness finding (MPEP 2144.05).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to optimize the amount of titanium in the work function material such that the WFM material comprises a concentration of titanium that is in a range of greater than 0% and less than 1.5% of the WFM because "[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).
Regarding claim 22, Fig. 10B of Ando further teaches where the WFM (Any of Items 231/234/232) is disposed between the plurality of nanostructure channels (Items 104) and a filling metal (Item 230) of the transistor.
Regarding claim 23, Fig. 10B of Ando further teaches where the transistor comprises a nanosheet transistor (Paragraph 0059).
Regarding claim 24, Fig. 10B of Ando further teaches where the channel structure comprises multiple channels (Items 104), and wherein the WFM (Any of Items 231/234/232) is disposed around individual channels of the multiple channels (Items 104).
Regarding claim 25, Fig. 10B of Ando further teaches forming an additional WFM (Any of the other of Items 231/234/232) disposed around the WFM (Any of Items 231/234/232).
Regarding claim 28, Fig. 1B of Zhang further teaches where the additional WFM (Any of the other of Items 231/234/232) comprises a titanium nitride (TiN) based material (Paragraph 0075).
Regarding claim 29, Fig. 1B of Zhang further teaches where the WFM is an n-type WFM (Fig. 10B).
Claims 30 and 31 are rejected under 35 U.S.C. 103 as being unpatentable over Lin et al. (US 10,535,523) hereinafter “Lin” in view of Lee et al. (US 9,240,483) hereinafter “Lee”.
Regarding claim 30, Figs. 2 and 3A of Lin teach a method, comprising: forming source/drains (Item S/D) on a surface of a substrate (Item 213) of a transistor; forming a channel extending between the source/drains and within the substrate (Item 213); and forming a work function material (WFM) (Item 205), that includes aluminum and carbon (Column 12, Lines 40-41 where TiAlC is used), disposed above the channel, and forming a gate (Item 207) disposed on the WFM (Item 205).
Lin does not explicitly teach where the WFM comprises a concentration of titanium that is in a range of greater than 0% to less than 1.5% of the WFM.
However, the concentration of titanium in a TiAlC material is a result effective variable (Lee Column 5, Lines 60-63 where the amount of Ti in a TiAlC work function material may be adjusted and Lee Column 6, Lines 54-61 where the work function of a transistor may be tuned according to the composition of a TiAlC work function material). In In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977), the CCPA held that a particular parameter must first be recognized as a result-effective variable, i.e., a variable which achieves a recognized result, before the determination of the optimum or workable ranges of said variable might be characterized as routine experimentation, because "obvious to try" is not a valid rationale for an obviousness finding (MPEP 2144.05).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to optimize the amount of titanium in the work function material such that the WFM material comprises a concentration of titanium that is in a range of greater than 0% and less than 1.5% of the WFM because "[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).
Regarding claim 31, Fig. 3A of Lin further teaches where the transistor comprises a FinFET transistor (Column 4, Lines 52-53).
Under an alternative interpretation of Ando, Claims 25-27 are rejected under 35 U.S.C. 103 as being unpatentable over Ando et al. (US 2021/0328103) hereinafter “Ando” in view of Lee et al. (US 9,240,483) hereinafter “Lee” and in further view of Zhang et al. (US 10,700,064) hereinafter “Zhang”.
Regarding claim 25, the combination of Ando and Lee teaches all of the elements of the claimed invention as stated above except forming an interfacial layer disposed between the WFM and the channel structure or forming a high-k dielectric disposed between the WFM and the channel structure.
Fig. 1B of Zhang further teaches forming an interfacial layer (Column 8, Lines 24-29 where a thin interfacial layer is formed between the high-k dielectric and channel) disposed between the WFM (Item 163) and the channel structure (Items 112, 114 and 116), forming a high-k dielectric layer (Item 161) disposed between the WFM (Item 163) and the channel structure.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to form an interfacial layer disposed between the WFM and the channel structure and form a high-k dielectric disposed between the WFM and the channel structure because the interfacial layer helps aids in the interface between a silicon channel material and a high-k dielectric layer on the channel material (Zhang Column 19, Lines 38-49).
Regarding claim 26, the combination of Ando, Lee and Zhang teaches all of the elements of the claimed invention as stated above except where the interfacial layer comprises an oxide layer disposed directly on the channel structure.
Fig. 1B of Zhang further teaches where the interfacial layer comprises an oxide layer (Column 8, Lines 24-25 where silicon oxide is the interfacial layer) disposed directly on the channel structure (Item 112, 114 and 116).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the interfacial layer comprises an oxide layer disposed directly on the channel structure because the interfacial layer helps aids in the interface between a silicon channel material and a high-k dielectric layer on the channel material (Zhang Column 19, Lines 38-49).
Regarding claim 27, the combination of Ando, Lee and Zhang teaches all of the elements of the claimed invention as stated above except where the high-k dielectric layer comprises a hafnium oxide-based material disposed between the interfacial layer and the WFM.
Fig. 1B of Zhang further teaches where the high-k dielectric layer (Item 161) comprises a hafnium oxide-based material (Column 8, Lines 22-24) disposed between the interfacial layer and the WFM (Item 163).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the high-k dielectric layer comprises a hafnium oxide-based material disposed between the interfacial layer and the WFM because the interfacial layer helps aids in the interface between a silicon channel material and a high-k dielectric layer on the channel material (Zhang Column 19, Lines 38-49).
Claims 10, 11, 13, 14 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Ando et al. (US 2021/0328103) hereinafter “Ando” in view of Lin et al. (US 10,535,523) hereinafter “Lin” and in further view of Lee et al. (US 9,240,483) hereinafter “Lee”.
Regarding claim 10, Fig. 10B of Ando teaches a method, comprising: forming a channel structure (Items 104) of a transistor, the channel structure comprising a plurality of nanostructure channels (Items 104) over a substrate (Item 101) and extending between source/drains (Items 120) of the transistor; and forming a work function material (WFM) (Any of 231/234/232), that includes aluminum and carbon (Paragraph 0075 where Titanium Aluminum Carbide is used), around the channel structure.
Ando does not teach wherein forming the WFM around the channel structure includes applying a chemical soak, wherein a material of the chemical soak comprises an aluminum, carbon, and hydrogen based material.
Lin teaches forming a work function material (Item 105) that is TiAlC as part of a gate structure (Column 7, Lines 64-67), where forming the work function material includes applying a chemical soak, where a material of the chemical soak comprises an aluminum, carbon and hydrogen based material (Column 8, Lines 22-25 where TEA is used).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have forming the WFM around the channel structure include applying a chemical soak, wherein a material of the chemical soak comprises an aluminum, carbon, and hydrogen based material because this process is known to form a conformal work function layer having improved step coverage (Zhang Column 8, Lines 9-11) and “(C) Use of known technique to improve similar devices (methods, or products) in the same way” and/or “(D) Applying a known technique to a known device (method, or product) ready for improvement to yield predictable results” support a prima facie case of obviousness (MPEP 2143; See also KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007)).
Ando does not explicitly teach where the WFM comprises a concentration of titanium that is in a range of greater than 0% to less than 1.5% of the WFM.
However, the concentration of titanium in a TiAlC material is a result effective variable (Lee Column 5, Lines 60-63 where the amount of Ti in a TiAlC work function material may be adjusted and Lee Column 6, Lines 54-61 where the work function of a transistor may be tuned according to the composition of a TiAlC work function material). In In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977), the CCPA held that a particular parameter must first be recognized as a result-effective variable, i.e., a variable which achieves a recognized result, before the determination of the optimum or workable ranges of said variable might be characterized as routine experimentation, because "obvious to try" is not a valid rationale for an obviousness finding (MPEP 2144.05).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to optimize the amount of titanium in the work function material such that the WFM material comprises a concentration of titanium that is in a range of greater than 0% and less than 1.5% of the WFM because "[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).
Regarding claim 11, the combination of Ando, Lin and Lee teaches all of the elements of the claimed invention as stated above.
Ando does not teach where the chemical soak is a triethylaluminum soak, and wherein applying the chemical soak comprises: applying the triethylaluminum for an amount of time configured to produce the WFM having a desired thickness.
Lin further teaches where a chemical soak is a triethylaluminum soak (Column 8, Lines 22-25), and wherein applying the chemical soak comprises: applying the triethylaluminum for an amount of time configured to produce the WFM having a desired thickness (Column 8, Lines 25-29).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the chemical soak is a triethylaluminum soak, and wherein applying the chemical soak comprises: applying the triethylaluminum for an amount of time configured to produce the WFM having a desired thickness because this is known to produce a TiAlC film having a desired thickness (Lin Column 8, Lines 15-16 and Lines 28-29).
Regarding claim 13, Fig. 10B of Ando further teaches where forming the WFM (Any of Items 231/234/232) around the channel structure (Items 104) comprises: depositing the WFM around the high-k dielectric layer (Paragraph 0075).
Regarding claim 14, Fig. 10B of Ando further teaches depositing, after forming the WFM (Any of Items 231/234/232) around the channel structure (Items 104), a filling metal (Item 230) around the WFM.
Regarding claim 17, Fig. 10B of Ando further teaches where the channel structure comprises multiple channels (Any of Items 231/234/232) extending between source/drains (Items 120) of the transistor, and wherein forming the WFM around the channel structure comprises depositing the WFM around individual channels of the multiple channels (Items 104).
Claims 12, 15 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Ando et al. (US 2021/0328103) hereinafter “Ando” in view of Lin et al. (US 10,535,523) hereinafter “Lin” and Lee et al. (US 9,240,483) hereinafter “Lee” and in further view of Zhang et al. (US 10,700,064) hereinafter “Zhang”.
Regarding claim 12, the combination of Ando, Lin and Lee teaches all of the elements of the claimed invention as stated above except depositing an interfacial layer on the channel structure; and depositing a high-k dielectric layer on the interfacial layer.
Fig. 1B of Zhang further teaches depositing an interfacial layer (Column 8, Lines 24-29 where a thin interfacial layer is formed between the high-k dielectric and channel) on the channel structure; and depositing a high-k dielectric layer (Item 161) on the interfacial layer.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to deposit an interfacial layer on the channel structure; and deposit a high-k dielectric layer on the interfacial layer because the interfacial layer helps aids in the interface between a silicon channel material and a high-k dielectric layer on the channel material (Zhang Column 19, Lines 38-49).
Regarding claim 15, the combination of Ando, Lin and Lee teaches all of the elements of the claimed invention as stated above except forming the WFM around an additional channel structure of an additional transistor of a same electronic device as the transistor, wherein the WFM has a first thickness around the channel structure, and wherein the WFM has a second thickness around the additional channel structure, wherein the first thickness is different from the second thickness.
Fig. 1B of Zhang further teaches forming the WFM (Item 163) around an additional channel structure (Combination of Items 122, 124 and 126) of an additional transistor of a same electronic device as the transistor, wherein the WFM (Item 163) has a first thickness around the channel structure (Combination of Items 112, 114 and 116), and wherein the WFM (Item 163) has a second thickness around the additional channel structure (Combination of Items 122, 124 and 126), wherein the first thickness is different from the second thickness.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to form the WFM around an additional channel structure of an additional transistor of a same electronic device as the transistor, wherein the WFM has a first thickness around the channel structure, and wherein the WFM has a second thickness around the additional channel structure, wherein the first thickness is different from the second thickness because this yields a device having multi-threshold voltage gate-all-around field effect transistor devices (Zhang Abstract).
Regarding claim 16, the combination of Ando, Lin, Lee and Zhang teaches all of the elements of the claimed invention as stated above.
Zhang does not explicitly teach where the WFM has a thickness that is greater than 0 angstroms and less than 12 angstroms.
However, the thickness of the WFM is known to be a result effective variable (Zhang Column 20, Lines 31-41 where the WFM is deposited with sufficient thickness to completely fill remaining portions of the channel spaces above and below the active nanosheet channel layers). In In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977), the CCPA held that a particular parameter must first be recognized as a result-effective variable, i.e., a variable which achieves a recognized result, before the determination of the optimum or workable ranges of said variable might be characterized as routine experimentation, because "obvious to try" is not a valid rationale for an obviousness finding (MPEP 2144.05).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to optimize the thickness of the WFM such that the WFM has a thickness that is greater than 0 angstroms and less than 12 angstroms because "[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).
Claim 32 is rejected under 35 U.S.C. 103 as being unpatentable over Lin et al. (US 10,535,523) hereinafter “Lin” in view of Lee et al. (US 9,240,483) hereinafter “Lee” and in further view of Zhang et al. (US 10,700,064) hereinafter “Zhang”.
Regarding claim 32, the combination of Lin and Lee teaches all of the elements of the claimed invention as stated above except forming a tunneling dielectric between the channel and the WFM.
Fig. 1B of Zhang further teaches forming an tunneling dielectric (Column 8, Lines 24-29 where a thin interfacial layer is formed between a high-k dielectric and channel) between a channel structure (Items 112, 114 and 116) and a WFM (Item 163).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to form a tunneling dielectric between the channel and WFM because the tunneling dielectric serves as an interfacial layer such that device performance is not degraded (Zhang Column 19, Lines 36-50).
Response to Arguments
Applicant’s arguments, see Applicant’s REMARKS, filed 04/28/2026, with respect to the rejection(s) of claim(s) 10 and 21 under 35 USC 103(a) have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Lee.
Applicant’s arguments, see Applicant’s REMARKS, filed 04/28/2026, with respect to the rejection(s) of claim(s) 30 under 35 USC 103(a) have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of another embodiment of Lee.
Examiner’s Note: The Applicant’s specification seems to suggest that a desired thickness of a TiAlC between 0 and 12 angstroms is only achievable when the titanium composition of TiAlC is between 0 and 1.5%. However, while not relied upon in a specific rejection above, Yang et al. (US 2019/0057863) teaches where a TiAlC layer is deposited to a thickness of about 2-10 angstroms (Paragraph 0023). Thus, either the prior art (such as Yang) recognizes forming a TiAlC layer having a thickness of less than 12 angstroms without the need for the titanium concentration to be between 0 and 1.5% or one having ordinary skill in the art would understand from Yang that the TiAlC layer formed having a thickness between 2 and 10 angstroms would have a titanium concentration between 0 and 1.5%. As such, Yang may also be relied upon to show obviousness of the titanium range when a desired thickness is greater than 0 and less than 12 angstroms.
Citation of Pertinent Prior Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Raisanen et al. (US 2019/0221433) teaches the concentration of titanium in a TiAlC material is a result effective variable where the amount of Ti in a TiAlC work function material may be adjusted to less than 10% (Paragraph 0063) and where the work function of a transistor may be tuned to have a desired work function according to the composition of a TiAlC work function material (Paragraph 0066).
Yang et al. (US 2019/0057863) teaches where a TiAlC layer is deposited to a thickness of about 5 angstroms (Paragraph 0023).
Conclusion
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ERIC K ASHBAHIAN whose telephone number is (571)270-5187. The examiner can normally be reached 8-5:30 PM.
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/ERIC K ASHBAHIAN/ Primary Examiner, Art Unit 2891
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