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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on January 13, 2025 is being considered by the examiner.
Election/Restrictions
Claims 14-33 are pending in this application.
Applicant’s election without traverse of Invention II (claims 14-20 and newly added claims 21-33) in the reply filed on June 29, 2026 is acknowledged. All nonelected claims were cancelled in the amendment dated June 29, 2026. The Examiner notes claims 14-33 are examined.
Response to Amendment
This Office Action is in response to Applicant’s Amendment filed June 29, 2026. Claims 1-13 are cancelled. Claims 21-33 are newly added. The Examiner notes that claims 14-33 are examined.
Claim Rejections - 35 USC § 102
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 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)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 28-29 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Kim (US 2024/0290808 A1).
With respect to claim 28, Kim teaches in Figs. 13A-19:
A method of forming an integrated device, comprising:
etching first openings (first trench 110T) into a first side (side at top of Fig. 13B) of a substrate (substrate 102) comprising the first side (top), a second side (bottom) opposite the first side, and a plurality of pixel regions (regions between the trenches),
wherein the first openings are symmetrically disposed around a middle axis (see annotated Figs. 9 and 19 below for definition of middle axis) between the plurality of pixel regions and comprise trenches extending between the plurality of pixel regions (see Fig. 9, the trenches of Fig. 13A correspond to separation films 312, 314A and 316) ;
forming a frontside deep trench isolation (DTI) structure within the first openings (Fig. 14A-14B, separation structure DT1);
forming a plurality of photodetectors (photodiodes PD1-PD4, for example) in the plurality of pixel regions, wherein the plurality of photodetectors are symmetrically disposed around the middle axis;
forming a first doped region (floating diffusion region FD and opening area OP, which may be formed of silicon doped with P-impurities, see para. 0040) at the middle axis on the first side of the substrate and between the plurality of photodetectors (PD2 and PD3)(see Fig. 16A);
etching second openings (second trench 115A) into the second side of the substrate (top side of substrate after substrate is flipped, see Fig. 18), wherein an opening of the second openings is on the middle axis and extends to the first doped region;
and forming a backside DTI structure (DT2) in the second openings and spacing the frontside DTI structure from the middle axis (see Fig. 9).
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With respect to claim 29, Kim further teaches:
wherein the middle axis is perpendicular to the first side and the second side (see annotated Fig. 19 above).
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 30-31 are rejected under 35 U.S.C. 103 as being unpatentable over Kim (US 2024/0290808 A1) as applied to claim 28 above and further in view of Hsu (US 2024/0030261 A1).
The applied reference has a common applicant and some common inventors with the instant application. Based upon the publication date before the effective filing date of the invention, it constitutes prior art under 35 U.S.C. 102(a)(1).
This rejection under 35 U.S.C. 103 might be overcome by: (1) a showing under 37 CFR 1.130(a) that the subject matter disclosed in the reference was obtained directly or indirectly from the inventor or a joint inventor of this application and is thus not prior art in accordance with 35 U.S.C.102(b)(1)(A).
With respect to claim 30, Kim teaches all limitations of claim 28 upon which claim 30 depends. Kim fails to teach:
further comprising forming second doped regions with a different doping type from the first doped region before etching the second openings, wherein the second doped regions are separated from the first doped region by the plurality of photodetectors.
Hsu teaches:
further comprising forming second doped regions (well regions 110) with a different doping type (para. [0020] “The well regions 110 comprising the first doping type (e.g., p-type) opposite the second doping type (e.g., n-type) of the floating diffusion node”) from the first doped region before etching the second openings (isolation structure trench 1602, see Fig. 16B), wherein the second doped regions (floating diffusion node 108) are separated from the first doped region by the plurality of photodetectors (photodetectors 106).
Kim discloses the claimed invention except for the second doped regions with a different doping type from the first region. Hsu teaches that it is known to form second doped regions with a different doping type that is separated from the first region by photodetectors. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Kim as taught by Hsu in order to provide connections to ground that minimize leakage current while shrinking the footprint of the device. See MPEP 2144.
With respect to claim 31, Hsu further teaches:
wherein the first doped region (108) extends into the plurality of pixel regions (see Fig. 2A) and is spaced from the plurality of photodetectors (106), and wherein the second doped regions (110) extend between segments of the frontside DTI structure (114) that are isolated by the substrate (102) and the backside DTI structure (116m).
It would have been obvious to one having ordinary skill in the effective filing date of the claimed invention to combine Kim in view of Hsu as explained above.
Claims 30 and 32 is rejected under 35 U.S.C. 103 as being unpatentable over Kim (US 2024/0290808 A1) as applied to claim 28 above and further in view of Lim (US 2022/0336514 A1).
With respect to claim 30, Kim teaches all limitations of claim 28 upon which claim 30 depends. Kim fails to teach:
further comprising forming second doped regions with a different doping type from the first doped region before etching the second openings, wherein the second doped regions are separated from the first doped region by the plurality of photodetectors.
Lim teaches:
further comprising forming second doped regions (first impurity regions 160) with a different doping type (p-type, para. [0049]) from the first doped region (floating diffusion region FD, n-type), wherein the second doped regions are separated from the first doped region by the plurality of photodetectors (separated in the D2 direction by photodiodes 110).
Kim discloses the claimed invention except for the second doping regions separated from the first doping regions by the photodetectors. Lim teaches that it is known to include a second doped region of the opposite conductivity type of the first doping region separated by the photodetectors. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Kim as taught by Lim in order to connect to the ground contact. See MPEP 2144.
Lim differs from the claimed invention because the doped regions are formed after etching the openings. However, Kim teaches that the first doped region is formed before etching the openings. It would be obvious to further modify Kim modified by Lim to include second doping regions such that the second doped regions are also formed before etching. The ordinary artisan would be motivated to make such a modification because doing so would simplify manufacturing by grouping doping implantations together in the manufacturing process and/or because selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results (In re Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946).
With respect to claim 32, Kim further teaches:
wherein the frontside DTI structure (DT1) comprises a first insulative liner (liner 116), wherein the backside DTI (DT2) structure comprises a second insulative liner (liner 117), and wherein the first insulative liner comprises segments that extend between the second insulative liner and the capping layer.
Kim fails to teach:
wherein the frontside DTI structure (second isolation pattern 153) comprises a capping layer (capping pattern 155)
Modifying Kim by Lim such that the frontside deep trench isolation structures DT1 have the structure of Lim’s pixel isolation pattern teaches that the first liner (151 of Lim, 116 of Kim) is between the capping structure (155 of Lim) and the insulating layer around the backside isolation structure of Kim (117), teaching the limitation:
and wherein the first insulative liner comprises segments that extend between the second insulative liner and the capping layer.
Kim discloses the claimed invention except for the capping structure in the frontside vias. Lim teaches that it is known to use an isolation structure that includes a capping layer in the frontside DTI as set forth at para. [0078] and Fig. 8C. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use the DTI structure including a capping layer as taught by Lim in order to treat the isolation structure to reduce dark current before depositing a capping layer to planarize the structure. See MPEP 2144.
Allowable Subject Matter
Claims 14-27 are allowed.
Claim 33 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.
The following is an examiner’s statement of reasons for allowance: The prior art of record does not fairly disclose or make obvious the claimed device as a whole.
With respect to claim 14, the closest prior art appears to be Hsu (US 2024/0030261 A1) and Kim (US 2024/0290808 A1).
Kim teaches a similar method in which a device is formed with DTI structures formed in both frontside and backside trenches including cross-shaped backside DTI structures that form a continuous loop with the frontside trenches. However, Kim does not teach that both the frontside and backside trenches are cross shaped and only the trenches formed in one side of the substrate consist of two cross shaped trenches. Therefore, Kim does not teach the combination of limitations “etching first openings into the first side of the substrate, the first openings comprising a first cross-shaped opening outlining the third corner of the pixel region and a second cross-shaped opening outlining the fourth corner of the pixel region; forming a frontside deep trench isolation (DTI) structure within the first openings; etching second openings into the second side of the substrate, the second openings comprising a third cross-shaped opening beneath the first corner of the pixel region and a fourth cross-shaped opening beneath the second corner of the pixel region” in combination with the additionally claimed features, as are claimed by the Applicant. Kim further teaches only the first doped region at the first corner of the pixel region and does not teach the limitation “forming a second doped region of a second conductivity type at the second corner of the pixel region.”
Hsu teaches a similar method that teaches the limitations “forming a first doped region of a first conductivity type at the first corner of the pixel region; forming a second doped region of a second conductivity type at the second corner of the pixel region;” but does not remedy the other deficiencies of Kim. Thus, the Applicant’s claims are determined to be novel and non-obvious.
Dependent claims 15-20 include all limitations of allowed independent claim 14 and are found allowable at least for the same reasons as the independent claim from which they depend.
With respect to claim 21, the closest prior art appears to be Kim (US 2024/0290808 A1).
Kim teaches a similar method in which a device is formed with DTI structures formed in both frontside and backside trenches including cross-shaped backside DTI structures that form a continuous loop. However, Kim does not teach that both the frontside and backside trenches are cross shaped and only the trenches formed in one side of the substrate consists of two cross shaped trenches. Therefore, Kim does not teach the combination of limitations “etching first openings into the first side of the substrate, the first openings comprising a first cross-shaped opening and a second cross-shaped opening having a center that is spaced from the first cross-shaped opening in a first direction and a second direction perpendicular to the first direction; forming a frontside deep trench isolation (DTI) structure within the first openings; etching second openings into the second side of the substrate, the second openings comprising a third cross-shaped opening and a fourth cross-shaped opening, wherein the third cross-shaped opening and the fourth cross-shaped opening expose sidewalls of the frontside DTI structure” in combination with the additionally claimed features, as are claimed by the Applicant. Thus, the Applicant’s claims are determined to be novel and non-obvious.
Dependent claims 22-27 include all limitations of allowed independent claim 21 and are found allowable at least for the same reasons as the independent claim from which they depend.
Regarding claim 33, prior art of record does not fairly disclose or make obvious the claimed device as a whole. Specifically, the closest prior art which has been made of record in the rejection of independent claim 28 above fails to disclose (by themselves or in combination) the limitations of “wherein etching the second openings results in segments of the frontside DTI structure being removed, and wherein after forming the backside DTI structure, an insulative liner of the backside DTI structure contacts a fill material of the frontside DTI structure” of claim 33 in combination with the additionally claimed features, as are claimed by the Applicant. Thus, the Applicant’s claims are determined to be novel and non-obvious.
Upon completing an updated prior art search and considering the combination of limitations as presented as a whole for the claims, the features highlighted above are considered an improvement over the prior art and have not been found to be anticipated or rendered obvious by a combination of prior art and the claimed invention directs to a novel and non-obvious method of making isolation structures that reduce the footprint of a photodetector device that has low defects that cause dark current and leakage current.
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
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AARON MICHAEL WEGNER whose telephone number is (571)270-7647. The examiner can normally be reached Mon-Fri 8:30 AM - 5 PM.
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/A.M.W./Examiner, Art Unit 2897
/JACOB Y CHOI/Supervisory Patent Examiner, Art Unit 2897
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