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 .
Response to Amendments
2. The Amendments filed February 18th, 2026 are noted. Applicant’s amendments to the Specification to overcome the objections set forth in the Non-Final Office Action mailed 11/19/2025 are noted. Applicant’s amendment(s) to the Specification have overcome the objection(s) to the Title previously set forth in the Non-Final Office Action mailed 11/19/2025, so the objection(s) to the Title has been withdrawn.
Applicant’s amendments to the claims are noted.
3. Claims 12-19 and 27 are now canceled; Claim 29 is newly-added; Claims 1-11, 20-26, and 28-29 remain pending in the application.
4. Claims 1-11, 20-26, and 28-29 have been fully considered in examination.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form 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 20-21, 23, 25-26, and 28-29 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Cheng (U.S. PG Pub No US2021/0335861A1).
Regarding claim 20, Cheng teaches a method [see figs. 6-20, 0031], comprising:
forming, in a first surface (122) fig. 20 [0016] of a substrate (128) fig. 6 [0032], a first, frustum-shaped (402 cross-section shape that of cone/pyramid with cut-off upper part) trench (402) fig. 6 [0032] filled with an insulating material (oxide [0032], the first, frustum-shaped trench (402) having a first end (top) with a first width (see annotated fig. 12 of Cheng below) and a second end (bottom) coplanar with the first surface (122) with a second width greater than the first width (see annotated figs. 12-13 of Cheng below);
forming, in a second surface (side of 128 coplanar with 130) [0032] of the substrate (128) opposite the first surface (122) along a first (vertical) direction, a second trench (1202) fig. 12 [0038] extending along the first (vertical) direction to the first, frustum-shaped trench (402), the second trench (1202) having a third width in a second (horizontal) direction transverse to the first direction the third width being smaller than the first and second widths (see annotated fig. 12 of Cheng below);
forming a first wide trench (1202 widened in fig. 13 by removal of 128’ by cleaning [0039]) in the second trench (1202), the first wide trench (1202 of fig. 13, forward) having a fourth width in the second (horizontal) direction greater than the first width and the third width (see annotated figs. 12-13 of Cheng below); and
forming a first material (112) fig. 16 [0042] (partially) filling the first wide trench (1202 of fig. 16) (see annotated figs. 12-13 of Cheng below).
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Annotated fig. 12 (left) and fig. 13 (right) of Cheng
Regarding claim 21, Cheng teaches the method [see figs. 6-20, 0031] of claim 20. Cheng also teaches wherein the forming the second trench (1202) fig. 12 [0038] includes anisotropic etching (anisotropic etching comprising TMAH [0039, 0020] may be used to form 1202 [0020, 0039]) from the second surface (side of 128 coplanar with 130) [0032] of the substrate (128) fig. 12 [0032] to the insulating material (oxide [0032]) of the first, frustum-shaped trench (402) fig. 6 [0032].
Regarding claim 23, Cheng teaches the method [see figs. 6-20, 0031] of claim 20. Cheng also teaches further comprising:
forming, in the first surface (122) fig. 20 [0016] of the substrate (128) fig. 6 [0032], a third trench (another 402) fig. 6 [0032] filled with the insulating material (oxide [0032]); and
forming, in the second surface (side of 128 coplanar with 130) [0032] of the substrate (128), a fourth trench (another 1202) fig. 12 [0038] extending along the first (vertical) direction to the third trench (another 402).
Regarding claim 25, Cheng teaches the method [see figs. 6-20, 0031] of claim 20. Cheng also teaches wherein the forming the first material (112) fig. 16 [0042] filling the first wide trench (1202, of fig. 13 forward) [0038, 0042] includes coating sidewalls of the first wide trench (1202) with a passivation layer (114) figs. 14-15 [0040-0041].
Regarding claim 26, Cheng teaches a method [see figs. 6-20, 0031], comprising:
forming, in a first surface (122) fig. 20 [0016] of a substrate (128) fig. 6 [0032] opposite a second surface (side of 128 coplanar with 130) [0032] along a first (vertical) direction, a first, frustum-shaped (402 cross-section shape that of cone/pyramid with cut-off upper part) plurality of trenches (402) fig. 6 [0032] filled with an insulating material (402) fig. 6 [0032]), each first, frustum-shaped trench (402) having a first end (top) opposite the first surface (122) along the first (vertical) direction, the first end having a first width along a second (horizontal) direction transverse to the first (vertical) direction (see annotated fig. 12 of Cheng below);
forming, in the second surface (side of 128 coplanar with 130) [0032] of the substrate (128), a second plurality of trenches (1202) fig. 12 [0038] each extending along the first (vertical) direction to a respective first, frustum-shaped trench (respective, underlying 402) of the first, frustum-shaped plurality of trenches (402), each second trench having a second width along the second (horizontal) direction that is smaller than the first width (see annotated fig. 12 of Cheng below);
widening (1202 widened in fig. 13 by removal of 128’ by cleaning [0039]) each of the second plurality of trenches (1202) to a third width along the second (horizontal) direction that is greater than the first and second widths (see annotated figs. 12-13 of Cheng below); and
(partially) filling each of the second plurality of trenches (1202) with at least one material (112) fig. 16 [0042].
[AltContent: rect][AltContent: textbox (2nd Width )][AltContent: textbox (3rd Width )][AltContent: textbox (Claim 26)]
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Annotated fig. 12 (left) and fig. 13 (right) of Cheng
Regarding claim 28, Cheng teaches the method [see figs. 6-20, 0031] of claim 26. Cheng also teaches wherein the filling each of the second plurality of trenches (1202) fig. 16 [0042] with the at least one material (112) fig. 16 [0042] includes:
forming a passivation layer (114) figs. 14-15 [0040-0041] on a plurality of sidewalls (right/left sidewalls) of each second trench (1202) of the second plurality of trenches (1202) and on an interface between each second trench (bottom of 1202) and the respective first, frustum-shaped trench (top of 402) fig. 14 [0032];
forming a dielectric layer (113) fig. 16 [0042] on the passivation layer (114); and
forming the at least one material (112) fig. 16 [0042] in a central region of each second trench (1202).
Regarding claim 29, Cheng teaches the method [see figs. 6-20, 0031] of claim 26. Cheng also teaches wherein the substrate (128) fig. 20 [0032] is a single continuous material extending from the first surface (122) fig. 20 [0016] to the second surface (side of 128 coplanar with 130) [0032].
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
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 1, 3-9, and 24 are rejected under 35 U.S.C. 103 as being unpatentable over Cheng (U.S. PG Pub No US2021/0335861A1) in view of Shinohara (U.S. PG Pub No US2012/0033119A1) (of record).
Regarding claim 1, Cheng teaches a method [see figs. 6-20, 0031], comprising:
forming a plurality of trenches (111/1202 with respective 402) fig. 20 [0028, 0032, 0042] in a semiconductor substrate (128) fig. 6 [0032], on a side of a first surface (122) fig. 20 [0016] of the substrate (128) by:
filling at least one first trench (402) fig. 6 [0032] of the plurality of trenches (111/1202 with 402) with an insulating material (oxide [0032]), vertically extending in the semiconductor substrate (128);
forming, by anisotropic etching (anisotropic etching comprising TMAH [0039, 0020] may be used to form 1202 [0020, 0039]) from a second surface (side of 128 coplanar with 130) [0032] of the semiconductor substrate (128) opposite to the first surface (122), at least one second trench (1202) fig. 12 [0038] of the plurality of trenches (111/1202 with 402) vertically extending in the substrate (128) and emerging onto the at least one first trench (402), the semiconductor substrate (128) being one continuous material extending from the first surface (122) to the second surface (side of 128 coplanar with 130); and
widening the at least one second trench (1202) (by removal of 128’ by cleaning in fig. 13 [0039]).
However, Cheng does not explicitly disclose and widening the at least one second trench (1202) by isotropic etching (isotropic etching not specified)
Shinohara teaches a method [see title, 0072] comprising widening the at least one second trench (to outer sidewall of 42B) fig. 2A [0072] by isotropic etching [0072].
Therefore, it would have been obvious to someone of ordinary skill in in the art before the effective filing date of the claimed invention to have modified the method of Cheng such that the second trench is shaped – at least in part – by an isotropic etching process [0072] in order to finely-tune [0072] the geometry of the trench sidewalls [0072] in order to promote element isolation between pixels to suppress color mixture and improve sensitivity [0064-0066, 0108] of the image sensor, as taught by Shinohara.
Regarding claim 3, Cheng in view of Shinohara teaches the method [see figs. 6-20, 0031] of claim 1. Cheng also teaches wherein the etching (anisotropic etching comprising TMAH [0039, 0020] may be used to form 1202 [0020, 0039]) from the second surface (side of 128 coplanar with 130) [0032] is a chemical etching (uses TMAH) [0038].
Regarding claim 4, Cheng in view of Shinohara teaches the method [see figs. 6-20, 0031] of claim 1. Cheng also teaches wherein the etching (anisotropic etching comprising TMAH [0039, 0020] may be used to form 1202 [0020, 0039]) from the second surface (side of 128 coplanar with 130) [0032] is an etching in liquid phase (uses wet TMAH [0038]).
Regarding claim 5, Cheng in view of Shinohara teaches the method [see figs. 6-20, 0031] of claim 1. Cheng also teaches comprising, after the widening [0039] the at least one second trench (1202) fig. 13 [0038-0039], filling the at least one second trench (1202) (with 112-114 material) fig. 16 [0040-0042].
Regarding claim 6, Cheng in view of Shinohara teaches the method [see figs. 6-20, 0031] of claim 5. Cheng also teaches wherein, the filling the at least one second trench (1202) fig. 16 [0040-0042] includes coating sides and a bottom of the at least one second trench (1202) fig. 13 [0038-0039] with at least one passivation layer (114) fig. 15 [0040-0041].
Regarding claim 7, Cheng in view of Shinohara teaches the method [see figs. 6-20, 0031] of claim 6. Cheng also teaches comprising coating the at least one passivation layer (114) fig. 15 [0040-0041] with at least one reflective dielectric layer (113, formed of at least partially reflective materials like aluminum oxide [0042]).
Regarding claim 8, Cheng in view of Shinohara teaches the method [see figs. 6-20, 0031] of claim 5. Cheng also teaches wherein, the filling of the at least one second trench (1202) fig. 16 [0040-0042] includes filling with a metal (metal-comprising layer 113 comprises various metal-oxides [0042].
Regarding claim 9, Cheng in view of Shinohara teaches the method [see figs. 6-20, 0031] of claim 1. Cheng also teaches wherein the at least one second trench (1202 of 111) fig. 20 [0042] is intended to insulate [0042] a pixel (103a) [0042] of an image sensor from neighboring pixels (103b) [0042].
Regarding claim 24, Cheng teaches the method [see figs. 6-20, 0031] of claim 20. However, Cheng does not explicitly disclose wherein the forming the first wide trench (1202 widened in fig. 13 by removal of 128’ by cleaning [0039]) [0038-0039] in the second trench (1202) fig. 12 [0038] includes an isotropic etching of the second trench (1202) (isotropic etching not specified).
Shinohara teaches a method [see title, 0072] comprising wherein the forming the first wide trench (widened to outer sidewall of 42B) fig. 2A [0072] in the second trench (42) fig. 2A [0072] includes an isotropic etching [0072].
Therefore, it would have been obvious to someone of ordinary skill in in the art before the effective filing date of the claimed invention to have modified the method of Cheng such that the second trench is shaped – at least in part – by an isotropic etching process [0072] in order to finely-tune [0072] the geometry of the trench sidewalls [0072] in order to promote element isolation between pixels to suppress color mixture and improve sensitivity [0064-0066, 0108] of the image sensor, as taught by Shinohara.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Cheng (U.S. PG Pub No US2021/0335861A1) modified by Shinohara (U.S. PG Pub No US2012/0033119A1) (of record), as applied in claim 1 above, and further in view of Hung (U.S. PG Pub No US2018/0017441A1) (of record).
Regarding claim 2, Cheng in view of Shinohara teaches the method [see figs. 6-20, 0031] of claim 1. However, Cheng does not explicitly disclose wherein the etching from the second surface (side of 128 coplanar with 130) [0032] is a reactive ion etching (dry etching mentioned [0038], however, deep reactive ion etching not explicitly specified).
Hung teaches a method [0059] wherein the etching from the second surface (116 of 110a) fig. 6A-6C [0060] is a reactive ion etching [0061].
Therefore, it would have been obvious to someone of ordinary skill in in the art before the effective filing date of the claimed invention to have modified the method of Cheng such that the second trench is shaped – at least in part – by an anisotropic reactive ion etching [0061] in order to provide localized sharp and straight-edged etched surfaces [0061-0062, 0073-0074] for well-controlled optical isolation [0062] and surface mounting of optical circuitry [0073-0074], as taught by Hung.
Claims 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over Cheng (U.S. PG Pub No US2021/0335861A1) modified by Shinohara (U.S. PG Pub No US2012/0033119A1) (of record), as applied in claim 1 above, and further in view of Cheng-II (U.S. Patent No 9,899,441) (of record).
Regarding claim 10, Cheng in view of Shinohara teaches the method [see figs. 6-20, 0031] of claim 1. However, Cheng does not explicitly disclose wherein the at least one second trench (1202) fig. 12 [0038] has, at an end of the etching [0038-0039], an aspect ratio in the order of thirty (aspect ratio not specified).
Cheng-II teaches a method [see title; col 7, lines 45-49] wherein the at least one second trench (106) fig. 4 [col 7, lines 50-63] has, at the end the etching includes an aspect ratio in the order of thirty (5-50, including 30) [col 7, lines 50-63].
Therefore, it would have been obvious to someone of ordinary skill in in the art before the effective filing date of the claimed invention to have modified the method of Cheng such that the second trench is provided with an aspect ratio in the range of about 5-50 (Height:Width) [col 7, lines 45-63 Cheng-II] in order to provide an advantageous degree of electrical and/or optical isolation between pixels [col 3, lines 1-13 Cheng-II] as well as desirable dopant control [col 2, lines 49-67], as taught by Cheng-II.
Regarding claim 11, Cheng in view of Shinohara teaches the method [see figs. 6-20, 0031] of claim 1. However, Cheng does not explicitly disclose wherein the at least one second trench (1202) fig. 13 [0038-0039] has, at an end of the widening [0038-0039], an aspect ratio in the order of ten (aspect ratio not specified).
Cheng-II teaches a method [see title; col 7, lines 45-49] wherein the at least one second trench (106) fig. 4 [col 7, lines 50-63] has, at the end of widening an aspect ratio in the order of ten (5-50, including 10) [col 7, lines 50-63].
Therefore, it would have been obvious to someone of ordinary skill in in the art before the effective filing date of the claimed invention to have modified the method of Cheng such that the second trench is provided with an aspect ratio in the range of about 5-50 (Height:Width) [col 7, lines 45-63 Cheng-II] in order to provide an advantageous degree of electrical and/or optical isolation between pixels [col 3, lines 1-13 Cheng-II] as well as desirable dopant control [col 2, lines 49-67], as taught by Cheng-II.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Cheng (U.S. PG Pub No US2021/0335861A1), as applied in claim 20 above, in view of Hung (U.S. PG Pub No US2018/0017441A1) (of record).
Regarding claim 22, Cheng teaches the method [see figs. 6-20, 0031] of claim 20. Cheng also teaches wherein the forming the second trench (1202) fig. 12 [0038] includes:
performing a photolithography [0038].
However, Cheng does not explicitly disclose forming the second trench includes performing a deep reactive ion etching (dry etching mentioned [0038], however, deep reactive ion etching not explicitly specified).
Hung teaches a method [0059] wherein the forming the second trench (605) fig. 6C [0062] includes:
performing a photolithography [0032, 0050] (in addition to dry etching [0050]); and
deep reactive ion etching (DRIE) [0061].
Therefore, it would have been obvious to someone of ordinary skill in in the art before the effective filing date of the claimed invention to have modified the method of Cheng such that the second trench is shaped – at least in part – by an anisotropic reactive ion etching [0061] in order to provide localized sharp and straight-edged etched surfaces [0061-0062, 0073-0074] for well-controlled optical isolation [0062] and surface mounting of optical circuitry [0073-0074], as taught by Hung.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1, 20, and 26 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
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
All references made available on the PTO-892 form(s) are considered relevant to the present disclosure because they all feature photo-electric devices with trenches.
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.
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/SEAN AYERS WINTERS/Examiner, Art Unit 2892 04/23/2026
/NORMAN D RICHARDS/Supervisory Patent Examiner, Art Unit 2892
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