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 .
This Office action is in response to the amendment filed 12/30/2025 in which claims 1, 4, 7, 9, and 21 were amended, claim 3 was cancelled, and claim 27 was added.
Claims 1, 2, 4-14, and 21-27 are pending with claims 7, 12, 13, and 26 remaining withdrawn and claims 1, 2, 4-6, 8-11, 14, 21-25, and 27 presented for examination.
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.
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 9 is rejected under 35 U.S.C. 103 as being unpatentable over Peng et al (US 2021/0249271 and Peng hereinafter) in view of Peuse et al (US 2010/0151694 and Peuse hereinafter).
Peng discloses a method ((Figs. 6A-8D) comprising: performing a radical oxidation process (Fig. 8B; plasma oxidation that uses oxygen radicals; [0044] and [0048]-[0050]) on a first vertical liner (66; [0042]) of an opening (96; [0042]), the radical oxidation process (plasma oxidation that uses oxygen radicals) oxidizing a first layer (66O; [0045]) of the first vertical liner (66); etching the first layer (66O) to remove the first layer (Fig. 8C; [0052]), a height to width ratio of the opening (96) being lessened by etching the first layer (Fig. 8C; [0052]-[0057]); depositing a gate dielectric (Fig. 8D; 108; [0058]) in the opening (96) on the first vertical liner (66); and depositing a gate electrode (110; [0058]-[0059]) over the gate dielectric (108).
Peng fails to expressly disclose wherein the radical oxidation process includes generating a plasma and neutralizing ions of the plasma.
Peng discloses a method of using a plasma oxidation process that comprises oxygen ions and oxygen radicals to oxidize the liner 66.
Peuse discloses a method of oxidizing a layer selectively using a plasma oxidation process where the ions are neutralized through the recombination of ions with electrons using a grid or baffle such that only the radicals are used to oxidize the material, [0025]-[0027] and [0041]-[0042].
Given the teachings of Peuse, a person having ordinary skill in the art before the effective filing date of the claimed invention would have readily recognized the desirability and advantages of modifying Peng by employing the well-known or conventional features of selective plasma oxidation processes, such as displayed by Peuse, by employing a plasma oxidation process that neutralizes ions in the generated plasma such that only radicals are used to modify/oxidize the layer in order to improve the oxide formed by minimizing damage and/or degradation of the oxide film ([0040]).
Claims 10, 11, and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Peng in view of Peuse as applied to claim 9 above, and further in view of Yen et al (US 2020/0075729 and Yen hereinafter).
As to claims 10, 11, and 14: Although the method disclosed by Peng in view of Peuse shows substantial features of the claimed invention (discussed in paragraph 8 above), it fails to expressly disclose:
[claim 10] wherein the opening exposes an isolation region, further comprising etching the isolation region to form a trench in the isolation region, wherein etching the isolation region is performed in the same process as etching the first layer; [claim 11] wherein the trench has an average depth between 0 nm and 20 nm, the average depth being non-zero; [claim 14] wherein after etching the first layer, the opening has a positive bias and a bottom of the opening has a round tip shape.
Peng in view of Peuse disclose a method of forming a transistor on a fin structure where an oxide (66O) is grown on a surface, and then the oxide (66O) and an underlying oxide (60) on a top surface of an STI (56) is removed, see Fig. 8C. The process of removing the oxide uses HF and an ammonia mixture, see [0053]. The opening of Peng will expose the STI when the gate oxide 60 is removed. The claim doesn’t state how the opening exposes the isolation region. The opening formed after etching the first layer of Peng is interpreted to be positive bias as it allows for the easy filling by the gate replacement structure.
Yen discloses in Figs. 14C, 14E, and 14G, a method of forming a transistor on a fin structure 116 (Fig. 14C) where an oxide 129 is grown on a surface including a layer 126 and the top of an STI structure 120 (Fig. 14E). The oxide 129 that is formed over the layer 126 and the oxide on top of the STI is removed (Fig. 14G). In removing the oxide 129 on stop of the STI, the STI is etched some, see [0064]-[0066]. Yen discloses that the oxide layer 129 and the STI oxide can be removed using HF and NH4 or ammonia mixture, see [0054] and [0066]. The STI 120 has a remainder portion in Fig. 14G. The amount of STI removed will be greater than 0 nm and less than around 15 nm ([0066]). The structure of Yen’s removal shows a rounded tip shape.
Therefore, Yen discloses that some over-etching of an STI oxide can occur due to the materials of the oxide layer 129 and oxide (similar to the STI oxide 56, oxide layer 66O, and oxide dielectric 60 of Peng) of the STI having similar etch selectivity relative to the HF and ammonia mixture.
Thus, a person having ordinary skill in the art before the effective filing date of the claimed invention would have recognized that the etch selectivity between the etching gas mixture of Peng in view of Peuse or Yen and that of the differing oxides of Peng (STI oxide, gate oxide 60, and oxidized layer 66O) being similar would result in over-etching of the STI oxide of Peng in view of Peuse once it is exposed by the removal of the gate oxide 60 as some amount of STI will be removed.
Further, a person having ordinary skill in the art before the effective filing date of the claimed invention would have had it within their ordinary capabilities to realize that in order to fully remove the oxides 60 and 66O, some amount of over-etching of the STI oxide will occur.
Claims 21, 23, and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Peng in view of Peuse in view of Yen.
As to claims 21, 23, and 25: Peng discloses [claim 21] a method (Figs. 2-8D) comprising: forming a fin (Fig. 2; 52; [0018]) protruding from a substrate (50; [0016]); forming an isolation region (Fig. 2; 56; [0020]) adjacent the fin (52), the fin (52) protruding (by H1; [0020]) above an upper surface of the isolation region (56); forming a dummy gate (Fig. 3; 62; [0028]) extending over the fin (52) and over the upper surface of the isolation region (56); forming a first spacer and a second spacer (Fig. 4A; 66; [0030]) on opposing sides of the dummy gate (62); removing the dummy gate (Fig. 8A; 62; [0042]) to form a recess (96; [0042]) between the first spacer and the second spacer (66), wherein sidewalls of the recess expose a sidewall (right sidewall) of the first spacer (66) and a sidewall (left sidewall) of the second spacer (66); performing a radical treatment process (Fig. 8B; plasma oxidation process that uses oxygen radicals; [0044]-[0048]) on the first spacer (66) to form a first modified layer (66O; [0045]) on the first spacer (66); etching the first modified layer (Fig. 8C; [0052]); depositing a gate dielectric (Fig. 8D; 108; [0058]) in the recess (96); and depositing a gate electrode (Fig. 8D; 110; [0058]) over the gate dielectric (108).
Peng fails to expressly disclose [claim 21] wherein the radical treatment process includes generating radicals, wherein the radicals react with material of the first spacer to form the first modified layer.
Peng discloses a method of using a plasma oxidation process that comprises oxygen ions and oxygen radicals to oxidize the liner 66.
Peuse discloses a method of oxidizing a layer selectively using a plasma oxidation process where the ions are neutralized through the recombination of ions with electrons using a grid or baffle such that only the radicals are used to oxidize the material, [0025]-[0027] and [0041]-[0042].
Given the teachings of Peuse, a person having ordinary skill in the art before the effective filing date of the claimed invention would have readily recognized the desirability and advantages of modifying Peng by employing the well-known or conventional features of selective plasma oxidation processes, such as displayed by Peuse, by employing a plasma oxidation process that neutralizes ions in the generated plasma such that only radicals are used to modify/oxidize the layer in order to improve the oxide formed by minimizing damage and/or degradation of the oxide film ([0040]).
Peng in view of Peuse fail to expressly disclose [claim 21] wherein etching the first modified layer recesses the upper surface of the isolation region; [claim 23] wherein a roughness of the isolation region under the gate dielectric is between 0 nm and 5 nm; [claim 25] wherein etching the first modified layer recesses the upper surface of the isolation region to a depth in a range of 0 nm to 20 nm.
Peng in view of Peuse disclose a method of forming a transistor on a fin structure where an oxide (66O) is grown on a surface, and then the oxide (66O) and an underlying oxide (60) on a top surface of an STI (56) is removed, see Fig. 8C. The process of removing the oxide uses HF and an ammonia mixture, see [0053]. The opening of Peng will expose the STI when the gate oxide 60 is removed.
Yen discloses in Figs. 14C, 14E, and 14G, a method of forming a transistor on a fin structure 116 (Fig. 14C) where an oxide 129 is grown on a surface including a layer 126 and the top of an STI structure 120 (Fig. 14E). The oxide 129 that is formed over the layer 126 and the oxide on top of the STI is removed (Fig. 14G). In removing the oxide 129 on stop of the STI, the STI is etched some, see [0064]-[0066]. Yen discloses that the oxide layer 129 and the STI oxide can be removed using HF and NH4 or ammonia mixture, see [0054] and [0066]. The STI 120 has a remainder portion in Fig. 14G. The amount of STI removed will be greater than 0 nm and less than around 15 nm ([0066]).
Therefore, Yen discloses that some over-etching of an STI oxide can occur due to the materials of the oxide layer 129 and oxide (similar to the STI oxide 56, oxide layer 66O, and oxide dielectric 60 of Peng) of the STI having similar etch selectivity relative to the HF and ammonia mixture.
Thus, a person having ordinary skill in the art before the effective filing date of the claimed invention would have recognized that the etch selectivity between the etching gas mixture of Peng in view of Peuse or Yen and that of the differing oxides of Peng (STI oxide, gate oxide 60, and oxidized layer 66O) being similar would result in over-etching of the STI oxide of Peng in view of Peuse once it is exposed by the removal of the gate oxide 60 as some amount of STI will be removed.
Further, a person having ordinary skill in the art before the effective filing date of the claimed invention would have had it within their ordinary capabilities to realize that in order to fully remove the oxides 60 and 66O, some amount of over-etching of the STI oxide will occur.
Allowable Subject Matter
Claims 1, 2, 4-8, 24, and 27 are allowed over the prior art of record.
The following is a statement of reasons for the indication of allowable subject matter: the closest prior art, Peng, discloses a method (Figs. 6A-8D) comprising: removing a dummy gate (Figs. 6A, 7A, and 8A; 62; [0039]-[0040]) over a semiconductor fin (Fig. 6B; 52; [0037]), to reveal a spacer (Fig. 8A; 66; [0042]) lining an opening (96; [0042]); oxidizing an outer layer of the spacer (Fig. 8B; [0044]-[0051]) by a radical treatment process (plasma oxidation that uses oxygen radicals; [0048]-[0050]) to form a first oxidized layer (66O; [0045]) of the spacer (66); etching the first oxidized layer (66O) of the spacer (66) to remove the first oxidized layer (Fig. 8C; [0052]); and forming a replacement metal gate (Fig. 8D; 110; [0058]-[0059]) in the opening (96). Peng fails to expressly disclose after etching the first oxidized layer of the spacer, performing a second radical treatment process to form a second oxidized layer of the spacer; etching the second oxidized layer of the spacer to remove the second oxidized layer.
Claim 22 is 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
Examiner notes that applicant’s arguments on page 7 with regard to the teaching of the subject matter of claim 7 with the identified species, Examiner agrees. Claim 7 is no longer considered withdrawn. As claim 1 is indicated as allowable, claim 7 is also allowable.
Applicant's arguments filed 12/30/2025 have been fully considered but they are not persuasive.
In the remarks, applicant argues in substance that claims 12, 13, and 26 are described with reference to the elected Species. Paragraph [0087] of the specification states “[t]he process described with respect to Figures 16A-16F may then be performed to thin the spacers 81 using a radical process to oxidize a layer of the spacers 81, followed by an etch process to remove the oxidized layer of the spacers.” With respect to Figure 16A, paragraph [0060] states “[e]xposed surfaces of the first nanostructures 52 in the p-type region 50P and exposed surfaces of the second nanostructures 54 in the n-type region 50N may also be oxidized by the first radical treatment process.” With respect to Figure 16B, paragraph [0061] states “[i]n addition to thinning the first spacers, the exposed oxidized surfaces of the first nanostructures 52 and second nanostructures 54 may be trimmed also.” Therefore, the subject matter of claim 26 (applicant states claim 22 on page 7, but Examiner believes that was a error and 26 is meant to be referenced) are described with reference to the elected Species. Regarding claims 12 and 13, the discussion referencing Figures 16A-16F, and Figures 17A-17B and Figures 18A-18B are described as the result of the processes discussed with reference to Figures 16A-16F, see [0069]-[0070]. Claims 12 and 13 are discussed with reference to Figures 18A-18B in paragraph [0072]. Therefore, claims 12 and 13 are also described with reference to the elected Species.
Examiner respectfully traverses applicant’s remarks. In regard to the teaching in [0060] of the fin structure, the paragraph specifically references nanostructures 52 and 54 and not fin structure 152 or channel 158 of the elected Species. As to claims 12 and 13, the applicant is arguing since Figs. 16A-16F are referenced by Figures 17A-17B and 18A-18B that the subject matter therein applies to the elected Species III, which is directed to Figures 24-26C. Paragraph [0087] of Species III specifically mentions only Figs. 16A-16F and not Figs. 17A-17B nor 18A-18B. While the specification states that the method can continue with those further figures, the discussion of Species III does not state that the method will continue with Figures 17A-17B and 18A-18B, only that the method of Figs. 16A-16F are used. Thus, claims 12, 13, and 26 remain withdrawn as being directed to a non-elected species.
Applicant’s arguments with respect to claims 9-11, 14, 21, 23, and 25 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.
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 JOSEPH C NICELY whose telephone number is (571)270-3834. The examiner can normally be reached Monday-Friday 7:30 am - 4 pm, EST.
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JOSEPH C. NICELY
Primary Examiner
Art Unit 2813
/JOSEPH C. NICELY/Primary Examiner, Art Unit 2813
3/24/2026