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 .
Status of Claims
Claims 1-3, 7-10, 21, 23-29, and 30-35 are pending.
Claims 1, 7, 9, 10, 21, 23, 24, 26-28, and 30 are amended.
Claims 4-6, 11-20, 22, and 29 are cancelled.
Claims 31-35 are new.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 03/11/2026 has been considered by the examiner.
Claim Rejections - 35 USC § 112
Applicant’s cancellation of claim 29 has overcome the rejection under 35 USC 112(a) of 12/30/2025. Accordingly, the rejection has been withdrawn.
Applicant’s amendment of the claim language of claim 26 and cancellation of claim 29 has overcome the rejection under 35 USC 112(b) of 12/30/2025. Accordingly, the rejections have been withdrawn.
Response to Arguments/Amendments
Applicant's arguments filed 03/27/2026 regarding amended independent claim 1 have been fully considered but they are not persuasive. Specifically, the amendment of the subject matter of previous claims 5 and 6 into independent claim 1 does not place the claim into condition for allowance. Applicant has requested clarification of citations of the Liu reference, as cited in the non-final office action of 12/30/2025. Examiner notes that all cited references should be considered in their entirety, however a clarified rejection of claim 1, as presented in the non-final rejection of 12/30/2025 is provided below:
Regarding claim 1, Liu (US Patent 8,617,348, herein known as Liu) teaches (Figs. 3A-3I) a method comprising: etching a gate stack (302, Col 10 Line 43, further disclosed to be a suitable method to utilize in transistor formation, Col 18, Line 53) to form a trench (312, Col 10 Line 45); depositing a silicon nitride liner (316, Col 10 Line 63) extending into the trench (312); and depositing a silicon oxide layer (320, Col 11 Line 2, Col 10 Line 13) on the silicon nitride liner (316). Lin does not explicitly teach performing a treatment process using a process gas comprising nitrogen and hydrogen; and performing a soaking process using a silicon precursor.
Liu teaches wherein the process of depositing silicon oxide can be performed using an appropriate ALD process in order to achieve fill of high aspect ratio features (Col 10 Line 13).
Choi teaches (Figure 5, below) performing a treatment process using a process gas comprising nitrogen and hydrogen (Inhibition Gas, Figure 5); and performing a soaking process using a silicon precursor (DIPAS, Figure 5).
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Because Liu and Choi are both directed toward deposition of silicon oxide through ALD, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Liu and Choi to include performing a treatment process using a process gas comprising nitrogen and hydrogen; and performing a soaking process using a silicon precursor, in order to achieve bottom-up growth without seam or gap formation of high aspect ratio trenches (Choi, Page 1).
The rejection of amended independent claim 1 is maintained. Accordingly, the rejections of dependent claims 2, 3, 7-10 are maintained.
Applicant's arguments filed 03/27/2026 regarding amended dependent claim 7 have been fully considered but they are not persuasive. Specifically, applicant argues that they were unable to locate in the reference of Choi where inhibition only affects the top of the trench and the surface region. An excerpt from Choi, Page 5 paragraph 2, (Bottom‑up plasma‑enhanced atomic layer deposition of SiO2 by utilizing growth inhibition using NH3 plasma pre‑treatment for seamless gap‑fill process, Scientific Reports, Nature.com 21 September 2022; hereinafter referred to as Choi) is provided herein:
“However, after NH3+ was performed (Fig. 8e–j), the inhibition only affected the top of the pattern (Fig. 8e), where the NH3+ was exposed; in turn, the growth was only inhibited on the surface and the top region (Fig. 8g). Therefore, the growth rate difference between the top and bottom regions of the pattern demonstrated bottom-up growth behavior (Fig. 8j).”
The rejection of amended claim 7 is maintained.
Applicant's arguments filed 03/27/2026 regarding amended dependent claim 8 have been fully considered but they are not persuasive. Specifically, applicant argues that Choi does not teach wherein “substantially all OH groups at the trench top are replaced with NH2 groups”
Choi teaches wherein NH3+ can suppress the growth of SiO2 thin films deposited vie PE-ALD by inactivating the Si-OH functional groups on the surface. As Choi refers to the Si-OH functional groups as “the Si-OH” functional groups and not “some of” or “a portion of” Si-OH functional groups on the surface, or another equivalent, it is interpreted under broadest reasonable interpretation that substantially all OH groups at the trench top are replaced in the reference of Choi.
The rejection of amended claim 8 is maintained.
Applicant’s arguments, see pages 9-10, filed 03/27/2026, with respect to amended independent claim 21 have been fully considered and are persuasive. The rejection of claim 21 under 35 USC 103 of 12/30/2025 has been withdrawn.
Specifically, inclusion of the claim limitation “forming a silicon nitride liner comprising an overhang, and a lower part underlying and joined to the overhang, wherein the overhang laterally protrudes toward a center middle line of the gate isolation region more than the lower part” overcomes the prior art rejection of record. The rejection of dependent claims 23-26 are withdrawn, accordingly.
Applicant’s arguments, see pages 10-11, filed 03/27/2026, with respect to the rejection of claim 27 under 35 USC 103 have been fully considered and are persuasive. Specifically, inclusion of new claim limitation forming a silicon oxide region over the silicon nitride liner, wherein an entire portion of the silicon oxide region lower than the first top surface level of the first gate stack is seam-free has not been previously considered and therefore overcomes the prior art rejection of record. Therefore, the rejection has been withdrawn. However, upon further consideration, a new grounds of rejection is made in view of Liu.
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.
Claims 1, 3, 7-10 are rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (US Patent 8,617,348; hereinafter referred to as Liu) in view of Choi et al. (Bottom‑up plasma‑enhanced atomic layer deposition of SiO2 by utilizing growth inhibition using NH3 plasma pre‑treatment for seamless gap‑fill process, Scientific Reports, Nature.com 21 September 2022; hereinafter referred to as Choi) and further in view of Lee et al. (Inhibitor-free area-selective atomic layer deposition of SiO2 through chemoselective adsorption of an aminodisilane precursor on oxide versus nitride substrates, Applied Surface Science, Vol 589, 1 July 2022; hereinafter referred to Lee).
Regarding claim 1, Liu teaches (Figs. 3A-3I) a method comprising: etching a gate stack (302, Col 10 Line 43, further disclosed to be a suitable method to utilize in transistor formation, Col 18, Line 53) to form a trench (312, Col 10 Line 45); depositing a silicon nitride liner (316, Col 10 Line 63) extending into the trench (312); and depositing a silicon oxide layer (320, Col 11 Line 2, Col 10 Line 13) on the silicon nitride liner (316). Lin does not explicitly teach performing a treatment process using a process gas comprising nitrogen and hydrogen; and performing a soaking process using a silicon precursor or wherein from a trench bottom to the trench top of the trench, replacing rates gradually increase, wherein the replacing rates are percentages of replacing the OH groups with NH2 groups.
Liu teaches wherein the process of depositing silicon oxide can be performed using an appropriate ALD process in order to achieve fill of high aspect ratio features (Col 10 Line 13).
Choi teaches (Figure 5, below) performing a treatment process using a process gas comprising nitrogen and hydrogen (Inhibition Gas, Figure 5); and performing a soaking process using a silicon precursor (DIPAS, Figure 5).
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Because Liu and Choi are both directed toward deposition of silicon oxide through ALD, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Liu and Choi to include performing a treatment process using a process gas comprising nitrogen and hydrogen; and performing a soaking process using a silicon precursor and teaches from a trench bottom to the trench top of the trench, replacing rates gradually increase, wherein the replacing rates are percentages of replacing the OH groups with NH2 groups, in order to achieve bottom-up growth without seam or gap formation of high aspect ratio trenches (Choi, Page 1).
Liu in view of Choi does not explicitly teach replacement with NH-comprising groups.
Lee teaches replacement with NH-comprising groups (Page 2, Results and Discussion).
Because Liu in view of Choi and Lee are both directed toward ALD of SiO2, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Liu in view of Choi and Lee to include replacement with NH-comprising groups in order to decrease the chemical adsorption of the precursor at the surface and top of the trench, in order to promote bottom-up growth (Lee, Page 2, Results and Discussion).
Regarding claim 3, Liu in view of Choi and Lee teaches the method of claim 1, wherein the process gas (Choi, Page 1) comprises ammonia (NH3)- (Fig. 5, above).
Regarding claim 7, Liu in view of Choi and Lee teaches the method of claim 1, wherein at a time the treatment process is stopped, substantially all OH groups at the trench bottom are unreplaced with NH2 groups (Choi, Page 5, paragraph 2 teaches that the inhibition only affects the top of the trench and surface region).
Regarding claim 8, Liu in view of Choi teaches the method of claim 1, wherein at a time the treatment process is stopped, substantially all OH groups at the trench top are replaced (Choi, Page 5, paragraph 2, Choi teaches inactivation of -OH groups at the trench top region).
Liu in view of Choi does not explicitly teach replacement with NH2 groups.
Lee teaches replacement with NH2 groups (Page 2, Results and Discussion).
Because Liu in view of Choi and Lee are both directed toward ALD of SiO2, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Liu in view of Choi and Lee to include replacement with NH2 groups in order to decrease the chemical adsorption of the precursor at the surface and top of the trench, in order to promote bottom-up growth (Lee, Page 2, Results and Discussion).
Regarding claim 9, Liu in view of Choi and Lee teaches (Choi, Fig. 5 above) the method of claim 1 further comprising, after the soaking process (DIPAS) is ended, starting an oxidation process (O2) on the silicon precursor that is adsorbed to the silicon nitride liner (Liu, 316, Col 10 Line 58).
Regarding claim 10, Liu in view of Choi and Lee teaches the method of claim 9, but does not explicitly teach wherein the oxidation process is controlled so that from the trench top to the trench bottom, substantially all adsorbed silicon-containing groups from the silicon precursor are converted as silicon oxide.
Choi further teaches wherein the ALD process exhibits self-limiting growth behavior induced by chemisorption of the precursor at the surface of the substrate, and that the process results in growth inhibition without N contamination (Page 4, paragraph 1).
Because Liu and Choi are both directed toward ALD of SiO2, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further combine the teachings of Liu and Choi in order to enable gap-free bottom-up growth of SiO2 (Choi, Page 1, paragraph 1).
Regarding claim 31, Liu in view of Choi and Lee teaches the method of claim 1, wherein from the trench bottom to the trench top of the trench, the replacing rates increase continuously. Choi teaches wherein as the trench is filled, there is a difference between the growth rate within the trench and the surface, by inactivating the surface, to enable bottom-up growth (Choi, Page 5).
Regarding claim 32, Liu in view of Choi and Lee teaches the method of claim 8, wherein at the time the treatment process is stopped, at the trench bottom, OH groups are partially replaced with the NH-comprising groups (Choi, Page 5).
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Liu in view of Choi and Lee as applied to claim 1 above, and further in view of Liu (US PGPub 2022/0165569; hereinafter referred to as Liu2).
Regarding claim 2, Liu in view of Choi and Lee teaches the method of claim 1, but does not explicitly teach wherein the process gas comprises a nitrogen gas (N2) and a hydrogen gas (H2).
Liu2 teaches wherein the process gas comprises a nitrogen gas (N2) and a hydrogen gas (H2) ([0071]).
Because Liu in view of Choi and Lee and Liu2 are both directed toward gapfill processes of Si02, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Choi and Liu2 to include wherein the process gas comprises a nitrogen gas (N2) and a hydrogen gas (H2) in order to advantageously fill a gap with a silicon-containing material (Liu2, [0071]). Additionally, absent a teaching of criticality of the use of N2 and H2, specifically, as it is given as an option among multiple deposition chemistries by the instant application, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize an appropriate noble gas chemistry for advantageous PEALD deposition, based upon the chosen precursor material, see MPEP 2141.III.B.
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Liu in view of Huang (US PGPub 2019/0164844; hereinafter referred to as Huang) and further in view of Ko et al. (US PGPub 2020/0006557; hereinafter referred to as Ko).
Regarding claim 27, Liu teaches a method comprising: forming a first semiconductor fin 302, Col 10 Line 43, further disclosed to be a suitable method to utilize in transistor formation, Col 18, Line 53) and a second semiconductor fin (302, 302, Col 10 Line 43, further disclosed to be a suitable method to utilize in transistor formation, Col 18, Line 53); and forming a gate isolation region between the first gate stack from the second gate stack, wherein the forming the gate isolation region comprises: forming a silicon nitride liner (316, Col 10 Line 63) comprising a portion contacting a sidewall of the first gate stack, wherein the portion has a first thickness (annotated Fig. 3B, T1) measured from a first top surface level of the first gate stack, and a second thickness (annotated Fig. 3B, T2) measured from a second top surface level and forming a silicon oxide region wherein an entire portion of the silicon oxide region lower than the first top surface level of the first gate stack is seam-free (Col 13 Line 28).
Liu does not explicitly teach forming a plurality of dielectric isolation regions in a semiconductor substrate, and fins extending higher than the plurality of dielectric isolation regions; forming a first gate stack and a second gate stack on the first semiconductor fin and the second semiconductor fin, respectively, and wherein from the first top surface level to the second top surface level, thicknesses of the portion of the silicon nitride liner increase.
Huang teaches wherein from the first top surface level (D7) to the second top surface level (D6), thicknesses of the portion of the silicon nitride liner increase ([0044]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to replace the liner of Liu with the liner of Huang for simple substitution with the predictable result of providing a dielectric protective layer over fin structures of a finFET device (Huang, [0008]). See MPEP 2141.III.B.
Ko teaches (Fig. 3) forming a plurality of dielectric isolation regions (22, [0012]) in a semiconductor substrate (20, [0012]), fins extending higher than the plurality of dielectric isolation regions (22, [0014]); forming a first gate stack (30, [0015]) and a second gate stack (30, [0015]) on the first semiconductor fin (24', [0014]) and the second semiconductor fin (24', [0014]), respectively.
Because Liu and Ko are both directed toward isolation of semiconductor fin devices, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Liu and of Ko in order to provide shallow trench isolation between adjacent fins (Ko, [0014]).
Claims 28 and 30 are rejected under 35 U.S.C. 103 as being unpatentable over Liu in view of Huang and Ko, as applied to claim 27 above, and further in view of Choi.
Regarding claim 28, Liu in view of Huang and Ko teaches the method of claim 27, wherein the forming the silicon oxide region comprises depositing a plurality of silicon oxide layers (ALD, [13]), and but does not explicitly teach wherein each of the plurality of silicon oxide layers have lower thicknesses greater than respective upper thicknesses.
Choi teaches higher growth rate at the bottom region of the trench than at the top region and the surface, i.e. ‘bottom-up’ growth (Choi, Page 2, paragraph 1)
Because Liu in view of Huang and Ko and Choi are both directed toward ALD deposition of SiO2, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Liu in view of Ko and of Choi to include wherein each of the plurality of silicon oxide layers have lower thicknesses greater than respective upper thicknesses in order to achieve seamless gap-fill of SiO2 (Choi, Page 2, paragraph 1).
Regarding claim 30, Liu in view of Huang, Ko, and Choi teaches the method of claim 28, wherein the depositing the silicon oxide region comprises a plurality of cycles (Choi, ALD), each comprising: (Choi, Figure 5, below) performing a treatment process using a process gas comprising nitrogen and hydrogen (Choi, Inhibition Gas, Figure 5, below); and performing a soaking process using a silicon precursor (Choi, DIPAS, Figure 5, below); and performing an oxidation process (Choi, Fig. 5 above, O2) on the silicon precursor (Choi, Page 10, paragraph 1).
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Objected to Allowable Subject Matter
Claims 32 and 35 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.
Regarding claim 32, the cited prior art of record does not teach or fairly suggest, along with the other claimed features, the method of claim 8, wherein at the time the treatment process is stopped, at the trench bottom, OH groups are partially replaced with the NH-comprising groups. Choi teaches wherein bottom-up gap fill of SiO2 is performed, and at a time the treatment process is stopped, the trench is filled with SiO2 only containing Si-OH bonding on the surface. It would not have been obvious to one of ordinary skill in the art to include wherein at the time the treatment process is stopped, at the trench bottom, OH groups are partially replaced with the NH-comprising groups, as this would mean incomplete surface recombination had occurred, and nitrogen contamination was present in the SiO2 fill. Prior art references alone or in combination, fail to disclose, teach, or suggest every limitation of the invention as claimed.
Regarding claim 35, the cited prior art of record does not teach or fairly suggest, along with the other claimed features, the method of claim 27, including wherein from the first top surface level of the first gate stack to a joining point of the upper portion and the bottom portion, thicknesses of the silicon nitride liner gradually and continuously reduce, and the bottom portion has a uniform thickness. Huang teaches wherein the silicon nitride liner (56, [0029]) comprises an upper portion, and a bottom portion underlying and joined to the upper portion, wherein from the first top surface level of the first gate stack to a joining point of the upper portion and the bottom portion, thicknesses of the silicon nitride liner gradually and continuously reduce, and the bottom portion has a uniform thickness. Huang teaches a silicon nitride liner with an upper thickness and a lower thickness that are different, but does not teach nor suggest wherein the upper portion has a thickness that is continuously reducing. Prior art references alone or in combination, fail to disclose, teach, or suggest every limitation of the invention as claimed.
ALLOWABLE CLAIMS
Claims 21, 23-26, 33, and 34 are allowed.
The following is an examiner’s statement of reasons for allowance:
Regarding claim 21, the cited prior art of record does not teach or fairly suggest, along with the other claimed features a method comprising forming a silicon nitride liner comprising an overhang, and a lower part underlying and joined to the overhang, wherein the overhang laterally protrudes toward a center middle line of the gate isolation region more than the lower part. Liu teaches an overhang of a silicon oxide layer over a silicon nitride liner, but teaches wherein the silicon nitride deposition is conformal to serve as an thin etch stop barrier for the underlying device, but does not teach nor suggest wherein the silicon nitride liner should contain an overhang, and a lower part underlying and joined to the overhang, wherein the overhang laterally protrudes toward a center middle line of the gate isolation region more than the lower part.
Prior art references alone or in combination, fail to disclose, teach, or suggest every limitation of the invention as claimed.
Claims 23-26, 33, and 34 are allowed as dependent on claim 21.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
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 EMILY N FARMER whose telephone number is (703)756-1472. The examiner can normally be reached Monday-Friday 7:30-5:00.
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/EMILY FARMER/Examiner, Art Unit 2812
/DAVIENNE N MONBLEAU/Supervisory Patent Examiner, Art Unit 2812
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