DETAILED ACTION
Claims 1-19 are pending and examined on their merits infra.
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 .
Domestic Benefit
Applicant has not claimed the benefit of any prior-filed domestic application under 35 U.S.C. 119(e), 120, 121, 365(c), or 386(c). The Application Data Sheet filed July 11, 2024 leaves the Domestic Benefit / National Stage section blank. The filing receipt of July 25, 2024 likewise states that no domestic benefit is claimed.
Foreign Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55 for Korean application 10-2024-0068287, filed in the Republic of Korea on May 27, 2024, electronically received by the Office on August 19, 2024.
Information Disclosure Statement
The information disclosure statement filed July 11, 2024 has been considered. The submission is in compliance with the provisions of 37 CFR 1.97.
Drawings
The drawings filed July 11, 2024 are accepted.
Specification
No objection to the specification is made.
Claim Interpretation
The claims are given their broadest reasonable interpretation. Limitations from a preferred embodiment are not read into the claims. MPEP 2111.01 II.
Applicant may be their own lexicographer only by clearly setting forth a special definition with reasonable clarity, deliberateness, and precision. MPEP 2111.01 IV. The specification does not do that for "first surface," "convex," or "structure." It says a first surface may be the upper surface or the lower surface, and that the scope is not limited to the preferred case in which the upper surface is concave and the lower surface is convex. That sentence does not redefine either term.
As used in the claims, "structure" is any film or layer on the oxide. The specification says a structure may be a polysilicon film, a metal film, or another film or layer, and that the scope is not limited to those examples.
Claim 1 recites a structure having a lower surface facing an upper surface of the oxide film, and, separately, a first surface of the oxide film having a convex shape. The claim does not tie the first surface to that upper surface. For examination, the first surface may be the upper surface or another surface of the oxide film. A convex upper surface, which is the surface the structure faces, meets the limitation.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1-5 are rejected under 35 U.S.C. 112(b) as being indefinite.
Claim 1 recites a structure having a lower surface facing an upper surface of the oxide film. Separately, claim 1 recites that the oxide film has a first surface having a convex shape. The claim does not state whether the first surface is that upper surface or a different surface of the oxide film.
The specification does not resolve it. A first surface may be the upper surface or the lower surface. Both readings are left open. A person of ordinary skill cannot tell which surface has to be convex.
Claims 2-5 depend from claim 1 and include this limitation.
For examination, the first surface is not limited to a surface other than the upper surface. A convex upper surface of the oxide film, which is the surface the structure faces, meets the limitation.
Claim Rejections - 35 USC § 102
The following is a quotation of 35 U.S.C. 102 that forms 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.
Claims 1 and 5 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Tan et al., U.S. Patent No. 6,001,706.
Tan issued December 14, 1999. It is prior art under 35 U.S.C. 102(a)(1). Different inventive entity.
Regarding claim 1, Tan teaches a semiconductor device (FIG. 12) comprising a substrate comprising a trench (substrate 10, device areas 3 separated by the field oxide); an oxide film disposed in the trench (field oxide 18, including polysilicon oxide 16'); and a structure disposed on the oxide film and having a lower surface facing an upper surface of the oxide film (gate electrode 22 on field oxide 18). The upper surface of oxide 18 is not straight. It rises over the trench and has rounded top corners at 16' and at the top upper surface. Those raised portions are convex. Gate 22 is formed on that surface. Because claim 1 does not require the first surface to be a surface other than the upper surface, the upper surface of oxide 18 is the first surface.
PNG
media_image1.png
620
375
media_image1.png
Greyscale
Tan, FIG. 12. Field oxide 18 in the trench, rounded shoulder 16', gate 22 on that oxide.
Regarding claim 5, the structure comprises a polysilicon film. Gate electrode 22 is doped polysilicon.
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.
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.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Ding, U.S. Patent Application Publication No. 2002/0045324, in view of Higgins et al., U.S. Patent No. 12,199,091.
Ding was published April 18, 2002. It is prior art under 35 U.S.C. 102(a)(1). Higgins issued January 14, 2025, and was effectively filed May 13, 2021. Higgins is prior art under 35 U.S.C. 102(a)(2). Different inventive entity. Not commonly owned with this application.
Ding teaches forming a trench in a substrate (shallow trench opening 206 in substrate 200a); forming an oxide film in the trench and on the substrate (insulation layer 210); and forming a device isolation film having a first oxide film in the trench by planarizing that oxide until the mask is exposed. After that planarization, Ding performs a thermal oxidation. Oxygen diffuses through the polished oxide and reacts with the silicon at the boundary, so that new oxide, liner 208, is grown at the silicon under the oxide that was already polished. The polished oxide remains and is densified, and the result is shallow trench isolation 212. That is forming a second oxide film by regrowing the first oxide film through a thermal oxidation performed on the first oxide film. Ding then removes the mask and the pad oxide and stops. Ding does not form a structure on the oxide.
Higgins teaches a device that uses a polished trench oxide as the isolation (STI 110) and deposits pre-metal dielectric 130 on that oxide and on the rest of the wafer. Dielectric 130 is a structure on the oxide. Higgins also forms doped polysilicon 116 on the isolation oxide. Polysilicon 116 is resistor 121.
Ding teaches the isolation and stops. What Ding leaves is an STI region. Ding does not teach a device on it. Higgins teaches that isolation inside a device, with dielectric 130 on the isolation oxide.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to recognize that combining Ding with Higgins would have been beneficial for using Ding's trench oxide, after Ding's thermal oxidation, as the isolation of Higgins's device so that dielectric 130 is formed on an isolation that Ding densifies and lines at the silicon in order to prevent an increase in current leakage and improve reliability. Dielectric 130 is the structure. It is deposited on the oxide after the oxidation, because Ding finishes that oxidation before the mask is removed, which is before the pre-metal dielectric is deposited.
The same combination meets a claim that depends from claim 6 and requires only that the structure comprises a polysilicon film, and a claim that further requires that polysilicon film to be a resistor. Higgins forms doped polysilicon 116 on the isolation oxide, and resistor 121 is that polysilicon. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to recognize that combining Ding with Higgins would have been beneficial for using Ding's trench oxide, after Ding's thermal oxidation, as the isolation under Higgins's polysilicon 116, including resistor 121, so that the polysilicon is formed on an isolation that Ding densifies and lines at the silicon in order to prevent an increase in current leakage and improve reliability.
Claims Not Rejected
Claims 2-4 and 7-19 are not rejected.
Claim 2 requires the surface opposite the first surface to be convex as well. In Tan, FIG. 12, the bottom of field oxide 18 is not shown as convex. Ding grows liner 208 at the silicon boundary and does not describe that boundary, or the top of the oxide, as convex.
Claim 3 requires that opposite surface to be concave. The same bottom in Tan is not shown as concave. Ding does not describe it as concave.
Claim 4 requires the oxide film of claim 1 to be formed by filling the trench and regrowing the trench. Tan fills the trench with oxide 18. Tan does not regrow that fill. Ding does regrow a polished trench oxide, but claim 4 depends from claim 1 and still requires the convex first surface. Ding does not teach that surface.
Claims 7-13 depend from claim 6. They are not rejected. The dielectric, the polysilicon film, and the resistor are the structure already applied against claim 6. Ding and Higgins do not teach a convex surface of the regrown oxide, a concave surface of that oxide, or dishing of the first oxide. A dependent claim that adds one of those limitations is not met.
Claim 14 requires the trench, the oxide fill, the polish, the regrowth of the polished oxide, a polysilicon resistor on the regrown oxide, and dishing of the first oxide. Higgins teaches the resistor on a polished trench oxide. Neither Ding nor Higgins teaches dishing of the oxide that is then regrown. Claims 15-19 depend from claim 14 and are not rejected.
Double Patenting
No double patenting rejection is made. No commonly owned United States application or patent claiming the same invention is of record.
Conclusion
A shortened statutory period for reply to this action is set to expire THREE MONTHS from the mailing date of this communication.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOHN P DULKA whose telephone number is (571)270-7398. The examiner can normally be reached Monday-Friday, 9am-5pm, EST.
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, ELISEO RAMOS-FELICIANO can be reached at (571)272-7925. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
26 September 2026
/John P. Dulka/Primary Examiner, Art Unit 2817
