DETAILED ACTION
Notice of Pre-AIA or AIA Status
1. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
2. This office action is responsive to applicant’s amendment filed on 11/10/2025. Claims 1-18 are pending. Claims 1-2 are withdrawn. Claim 3, 5, 7 are amended.
Response to Arguments
3. The applicant’s amendment filed on 11/10/2025 was sufficient to overcome the examiner’s previous ground of rejection under 35 U.S.C 112(b). However, applicant’s amendment raise new ground of rejection under 35 U.S.C 112(a) as discussed below.
Applicant’s arguments with respect to claim(s) 3-12, 14-16 under 35 U.S.C 103 rejection 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.
Claim Rejections - 35 USC § 112
4. The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
5. Claims 3-18 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
In lines 23-24 (last two lines) of claim 3, the examiner is unable to find proper support for the new limitation “the first protective layer on the surface of the corner region is not etched” (emphasis added). The examiner considers this is a negative limitation. The examiner interprets that this negative limitation means the etched amount of the first protective layer on the surface of the corner region is zero (Note: not etched means etch amount is zero). According to the MPEP 2173.05(i), “Any negative limitation or exclusionary proviso must have basis in the original disclosure”. It is noted that the first protective layer on the surface of the corner region is exposed during an etching process. Therefore the first protective layer on the surface of the corner region is subjected to an etching process to some degree (etch amount is greater than zero). The applicants fail to explicitly disclose that “the first protective layer on the surface of the corner region is not etched” (i.e. etching amount is zero). The examiner clearly recognizes that in Fig 9-10, the applicants clearly shown that the first protective layer on the surface of the corner region is remained after the etching process. Further, in paragraph [0068] of the present specification, the applicants wrote "in the third etching process, the first protective layer 205 at the bottom of the initial trench 203 is etched, and the first protective layer 205 on the side wall of the initial trench 203 can protect the corner region C in the subsequent etching process, reduce further etching of the corner region C in the subsequent etching process of forming the trench, and improve the size stability of the active region".
This means applicants only have support that the protective layer on the surface of the corner region is not completely etched during the etching process. Applicants do not have proper support for the new limitation “the first protective layer on the surface of the corner region is not etched”.
Claims 4-18 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because they directly or indirectly depend on rejected claim 1.
Claim Rejections - 35 USC § 103
6. 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.
7. 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.
8. Claims 3-4, 10-11, 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Sandhu et al. (US 2006/0292793 A1) in view of Chen (US 2008/0286978 A1), herein after refer as Chen (‘978).
Note:
As to claim 3, Sandhu discloses a method for forming a semiconductor structure, comprising:
providing a substrate (16);
forming a mask layer (20 or 22 or 24) on the substrate, wherein the mask layer exposes a part of a surface of the substrate (16) (Fig 3, paragraph 0033-0041);
etching the substrate by a
forming an insulating layer (62 or 72) in the plurality of trenches (Fig 7, Fig 11, paragraph 0052-0054, 0065);
wherein the
performing a first etching process, wherein a plurality of initial trenches are formed in the substrate, an initial active region is formed between the plurality of initial trenches, and a corner region is formed between a top and a side wall of the active region (Fig 3-Fig 4, paragraph 0041-0044);
performing a second etching process after the first etching process, wherein a reaction gas is introduced into an etching cavity to form a first protective layer (60) on a surface of the corner region exposed by the plurality of initial trenches, wherein the first protective layer is also formed at a bottom of the plurality of initial trenches (paragraph 0048-0050, Fig 5);
performing a third etching process after the second etching process, wherein the substrate at a bottom of the plurality of initial trenches is etched to form the active region and the plurality of trenches; wherein in the third etching process, the first protective layer at the bottom of the plurality of initial trenches is etched, and the first protective layer on the surface of the corner region is not etched (Fig 6-7, paragraph 0054-0057, Fig 7-8).
As to claim 3, Sandhu fails to disclose the etching the substrate by a plasma etching process. However, Sandhu clearly teaches to etch the substrate. Chen (‘978) discloses to etch the substrate using a plasma etching process (paragraph 0022-0024). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Sandhu in view of Chen (‘978) by using plasma etching process because equivalent and substitution of one for the other would produce an expected result.
As to claim 4, Sandhu discloses the first protective layer (60) is made by a material comprising silicon oxide (paragraph 0048).
As to claim 10, Sandhu discloses the insulating layer (62 or 72) is also disposed between adjacent mask layers (22 and 24) (See Fig 6, Fig 11, paragraph 0053-0054, 0065).
As to claim 11, Sandhu discloses forming the insulating layer (72) comprises:
forming an insulating material layer in the plurality of trenches and on a surface of the mask layer (22); and planarizing the insulating material layer until the surface of the mask layer is exposed (Fig 11, paragraph 0065-0066).
As to claim 14, Sandhu discloses the mask layer comprises a first mask layer (20) and the second mask layer (22) on the first mask layer (20) (paragraph 0034-0035).
As to claim 15, Sandhu discloses the first mask layer (20) is made by a material comprising silicon oxide (paragraph 0034) and the second mask layer (22) is made by a material comprising silicon nitride (paragraph 0035).
9. Claims 5-6 are rejected under 35 U.S.C. 103 as being unpatentable over Sandhu (US 2006/0292793 A1) in view of Chen (US 2008/0286978 A1) as applied to claims 3-4, 10-11, 14-15 above, and further in view of Liu (US 2022/0223381 A1).
As to claim 5, Sandhu and Chen (‘978) fail to disclose in the second etching process, the reaction gas comprises oxygen having a flow rate greater than or equal to 100 sccm, and a radio frequency power is greater than or equal to 900 W. As to claim 6, Sandhu and Chen (‘978) fail to disclose in the second etching process, the reaction gas comprises oxygen having a flow rate is in a range 100 sccm to 240 sccm, and a radio frequency power is greater than or equal to 900 W to 1300 W. However, Sandhu clearly discloses the second etching is an oxidation process (paragraph 0048-0050). Liu discloses a plasma oxidation process using oxygen gas at a flow rate of 100 sccm to about 3000 sccm and a RF power of 1 kW to about 10 kW (paragraph 0072; Note1 kW = 1,000 W; within applicant's range). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Sandhu and Chen (‘978) in view of Liu by having oxygen at 100 sccm and a RF power of 1000 Watts because in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (See MPEP 2144.05(I)).
10. Claims 7-9 are rejected under 35 U.S.C. 103 as being unpatentable over Sandhu (US 2006/0292793 A1) in view of Chen (US 2008/0286978 A1) as applied to claims 3-4, 10-11, 14-15 above, and further in view of Jung (KR 100325605 B1).
As to claim 7, Sandhu and Chen (‘978) fail to disclose forming a second protective layer on a sidewall and a bottom of the plurality of trenches after forming the plurality of trench and before forming the insulating layer. However, Sandhu clearly teaches forming the plurality of trenches and forming first protection layer on the sidewall. Jung disclose forming a second protective layer (first liner oxide) on a sidewall and a bottom of the plurality of trenches after forming the plurality of trench and before forming the insulating layer (second liner oxide) (See page 4). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Sandhu and Chen (‘978) in view of Jung by forming a second protective layer on the sidewall and bottom surface of the plurality of trenches because it will protect the trenches during subsequent etching step.
As to claim 8, Jung discloses forming the second protective layer comprises oxide layer (page 3). However, Jung fails to disclose the second protective layer comprises an in situ steam generation process. Sandhu discloses forming protective layer comprises silicon oxide using an in situ stem generation process (paragraph 0050). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Sandhu, Chen (‘978) in view of Jung by forming the second protective layer using in situ steam generation because equivalent and substitution of one for the other would produce an expected result (See MPEP 2143(I)(B)).
As to claim 9, Sandhu and Chen (‘978) fail to disclose a thickness of the second protective layer is in a range of 50 Å to 150 Å. Jung discloses a thickness of the second protective layer is between 100 to 150 Å (page 4, 4th paragraph, within applicant’s range). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Sandhu and Chen (‘978) in view of Jung by having a thickness of the second protective layer is in a range of 100 to 150 Å because in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (See MPEP 2144.05(I)).
11. Claims 12, 16-18 are rejected under 35 U.S.C. 103 as being unpatentable over Sandhu (US 2006/0292793 A1) in view of Chen (US 2008/0286978 A1) as applied to claims 3-4, 10-11, 14-15 above, and further in view of Chen et al. (US 2019/0165137 A1), herein after refers as Chen (‘137).
As to claim 12, Sandhu and Chen (‘978) fail to disclose the insulating material layer comprises high density plasma deposition process. However, Sandhu clearly discloses deposit an insulating material in the trench. Chen (‘137) discloses to deposit insulating material into the trench using high density plasma CVD (paragraph 0018). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Sandhu and Chen (‘978) in view of Chen (‘137) by forming insulating material using a high density plasma deposition process such as high density CVD because equivalent and substitution of one for the other would produce an expected result (See MPEP 2143(I)(B)).
As to claim 16, Chen (’978) discloses in the first etching process, an etching gas comprises one or more of HBr and etching power is in a range of 600 W (paragraph 0022). As to claim 16, Sandhu and Chen (‘978) fail to disclose a gas flow is in range of 15 sccm to 100 sccm. Chen (‘137) teaches to etch using HBr at a flow rate in a range from about 50 sccm to 800 sccm having a power of 200 W to 1500 W (paragraph 0045-0046; 0053; Note: 50 sccm is within applicant's range of 15 sccm to 100 sccm). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Sandhu and Chen (‘978) in view of Chen (‘137) by using HBr at a flow rate of 50 sccm and power of 1500 W because in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (See MPEP 2144.05(I)).
As to claim 17, Chen (’978) discloses in the first etching process, an etching gas comprises one or more of HBr As to claim 17, Sandhu and Chen (’978) fail to disclose in the third etching process, an etching gas comprises one or more of HBr, SF₆, CH₂F₂ or CH₃F, and a gas flow ranges is in a range of 20 sccm to 400 sccm. However, Sandhu clearly discloses a third etching process to create a trench (paragraph 0041-0042). Chen (‘137) discloses an anisotropic etching using HBr at a flow rate of 50 sccm (paragraph 0045-0046; 0053; Note: 50 sccm is within applicant's range of 15 sccm to 100 sccm). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Sandhu and Chen (‘978) in view of Chen (‘137) by using HBr at a flow rate of 50 sccm because in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (See MPEP 2144.05(I)).
As to claim 18, Sandhu fails to disclose a depth of the plurality of initial trenches is in a range of 1100 Å to 1500 Å. Chen (‘137) discloses the plurality of initial trenches have a depth in a range of 80 nm to 150 nm (paragraph 0016; Note: 150 nm = 1500 Å; within applicant's range of 1100 Å to 1500 Å). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Sandhu and Chen (‘978) in view of Chen (‘137) by having a plurality of trenches depth at 150 nm (150 nm = 1500 Å) because in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (See MPEP 2144.05(I)).
12. Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Sandhu (US 2006/0292793 A1) in view of Chen (US 2008/0286978 A1) as applied to claims 3-4, 10-11, 14-15 above, and further in view of Ogawa (US 2006/0276001 A1).
As to claim 13, Sandhu discloses removing the mask layer (22) and exposing a tope surface of the active region after forming insulating layer (72) (See Fig 11-Fig 12, paragraph 00678) and forming a gate electrode (paragraph 0070-0071). As to claim 13, Sandhu and Chen (‘978) fail to disclose forming a gate oxide layer on the surface of the active region and forming a gate electrode on the surface of the gate oxide layer. Ogawa discloses As to claim 13, Ogawa discloses removing the mask layer (12/13) and exposing a top surface of the active region after forming the insulating layer; and forming a gate oxide layer on a surface of the active region and forming a gate electrode on a surface of the gate oxide layer (Fig 1H; paragraph 0043-0044, Fig 6H; paragraph 0054-0057). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Sandhu and Chen (‘978) in view of Ogawa by forming a gate oxide layer on the surface of the active region and forming a gate electrode on the surface of the gate oxide layer because gate oxide will separate gate electrode from the substrate.
Conclusion
13. 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.
14. Any inquiry concerning this communication or earlier communications from the examiner should be directed to BINH X TRAN whose telephone number is (571)272-1469. The examiner can normally be reached Monday-Friday.
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.
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BINH X. TRAN
Examiner
Art Unit 1713
/BINH X TRAN/ Primary Examiner, Art Unit 1713
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