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 .
Election/Restrictions
Applicant’s election without traverse of group I in the reply filed on 03/11/2026 is acknowledged.
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.
Claim(s) 15-20, is/are rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al (US Pub No. 20200066768), in view of Huang et al (US Pub No. 20190221601), in view of Kusukawa (US Pub No. 20210313477), in view of Mouli (US Pub No. 20050151218).
With respect to claim 15, Cheng et al discloses an IC (Fig.1) a substrate (102); a plurality of image sensing elements disposed in the substrate (103a-c) and comprising a first doping type (104, para 19); and a deep trench isolation (DTI) structure (124,122,106) separating adjacent image sensing elements of the plurality of image sensing elements from one another (Fig.1) and comprising an isolation filler structure (106) disposed between sidewalls of the substrate (Fig.1); a doped isolation layer (122 , para 24) disposed between the isolation filler structure and the substrate and comprising a second doping type (para 24) opposite the first doping type (they are p-type), wherein the substrate is more heavily doped in a dopant diffusion region (124) extending from the doped isolation layer into the substrate by a first distance (Fig.1) . However, Cheng et al does not explicitly disclose wherein the doped diffusion region is more doped than the substrate and a light absorbing layer comprising a first material disposed between the isolation filler structure and the doped isolation layer wherein the first material has an absorption coefficient of greater than approximately 104 centimeters-1. On the other hand, Huang et al discloses the doped diffusion region (R2) is more doped than the substrate (Para 33). It would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify Cheng et al according to the teachings of the Huang et al such that the diffusion region is more doped than the substrate in order to reduce dark current, thereby increasing the lifetime of the device. However, the arts cited above do not explicitly disclose a light absorbing layer comprising a first material disposed between the isolation filler structure and the doped isolation layer wherein the first material has an absorption coefficient of greater than approximately 104 centimeter ^-1. On the other hand, Kusukawa discloses a light absorbing layer comprising a first material disposed between the isolation filler structure and the doped isolation layer wherein the first material has an absorption coefficient of greater than approximately 104 centimeter ^-1. On the other hand, Kusukawa discloses a light absorbing layer (400,Fig.1) comprising a first material (Aluminum oxide, para 20) disposed between the isolation filler structure (201) and the doped isolation layer (302) wherein the first material has an absorption coefficient of greater than approximately 104 centimeter ^-1 (Aluminum oxide has that kind of absorption). It would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify Cheng et al according to the teachings of Kusukawa such that aluminum oxide is used in the isolation trench in order to decrease the cross talk between pixels, thereby improving picture quality. However, Kusukawa discloses that aluminum oxide is used as a laminate structure, in order to show that aluminum oxide is a distinct layer examiner uses Mouli uses as evidence which shows layer 26 as an aluminum oxide layer (26, Fig.15, para 48). It would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify the arts above according to the teachings of Mouli such that Aluminum oxide is used as liner in the isolation trench in order to make a stable isolating trench.
With respect to claim 16, Kusukawa and Mouli disclose wherein the light absorbing layer comprises germanium, titanium nitride, aluminum oxide (para 20, para 48), or a silicon-germanium alloy.
With respect to claim 17 Kushukawa discloses, wherein the first material (400) extends from the DTI structure (201) into the substrate by a second distance (Fig.1) that is less than the first distance (124 in Cheng). Furthermore, "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
With respect to claim 18, the arts cited above do not explicitly disclose wherein a concentration of the first material in the substrate is less than approximately 3 percent. On the other hand, it would have been obvious one of ordinary skill in the art at the time of the filing of the invention to modify the arts cited above such that the first material in the substrate is less than approximately 3 percent, in order to increase the lifetime of the device. Furthermore, "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
With respect to claim 19, the arts cited above do not explicitly wherein the second distance is greater than approximately 1 nanometer. However, it would have been obvious to one of ordinary skill in the art at the time of the filing of the inventio to modify the arts cited above such that the second distance is greater than 1 nanometer, in order to make an effective isolation region, to decrease crosstalk between the devices. Furthermore, "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
With respect to claim 20, the arts cited above do not explicitly disclose wherein the first distance is greater than approximately 5 nanometers. On the other hand, it would have been obvious to one ordinary skill in the art at the time of the filing of the invention to modify the arts cited above such that the first distance is greater than approximately 5 nanometers, in order to improve the dark current suppression in the device. Furthermore, "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Claim(s) 35-43 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al (US Pub No. 20200066768), in view of Kusukawa (US Pub No. 20210313477), in view of Huang et al (US Pub No. 20190221601).
With respect to claim 35, Cheng et al discloses a substrate (102,Fig.1); a plurality of image sensing elements (103a-C) disposed in the substrate; and a deep trench isolation (DTI) structure (204 and 122) separating adjacent image sensing elements of the plurality of image sensing elements from one another (Fig.1,Fig.2A), the DTI structure comprising: an isolation filler structure (106) disposed within a trench (Fig.1), the trench defined by inner sidewalls of the substrate (under 122) ;a doped isolation layer (122) disposed between outer sidewalls of the isolation filler structure and the inner sidewalls of the substrate (Fig.1); and wherein the substrate is more heavily doped in a dopant diffusion region (124) extending from the DTI structure into the substrate (Fig.1). However, Cheng et al does not explicitly disclose a light absorbing layer disposed between the outer sidewalls of the isolation filler structure and inner sidewalls of the doped isolation layer; and wherein a light absorbing material extends into the substrate from the DTI structure toward an outer edge of the dopant diffusion region, and dopant diffusion region is more doped than the substrate. On the other hand, Kusukawa discloses a light absorbing layer (400,Fig.1) disposed between the outer sidewalls of the isolation filler structure (201) and inner sidewalls of the doped isolation layer (302); and wherein a light absorbing material extends into the substrate from the DTI structure (from 201 portion) toward an outer edge of the dopant diffusion region (towards lower corners of 302). It would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify Cheng et al according to the teachings of Kusukawa so that a light absorbing element such as aluminum oxide is used in the isolation trench in order to decrease the cross talk between pixels, thereby improving picture quality. However, the arts cited above do not explicitly disclose and dopant diffusion region is more doped than the substrate. On the other hand, Huang et al discloses the doped diffusion region (R2) is more doped than the substrate (Para 33). It would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify Cheng et al and Kusukawa according to the teachings of the Huang et al such that the diffusion region is more doped than the substrate in order to reduce dark current, thereby increasing the lifetime of the device
With respect to claim 36, Cheng et al discloses wherein the image sensing elements comprise a first doping type (Para 19), and the doped isolation layer comprises a second doping type opposite the first doping type (Para 19-24), and wherein the dopant diffusion region comprises the second doping type (Para 19-24).
With respect to claim 37, Kusukawa discloses wherein the light absorbing layer and the light absorbing material have an absorption coefficient of greater than approximately 104 centimeters-1 (Aluminum oxide has this absorbing coefficient, para 20). However, Kusukawa discloses that aluminum oxide is used as a laminate structure, in order to show that aluminum oxide is a distinct layer examiner uses Mouli uses as evidence which shows layer 26 as an aluminum oxide layer (26, Fig.15, para 48). It would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify the arts above such that Aluminum oxide is used as liner in the isolation trench in order to make a stable isolating trench.
With respect to claim 38, Cheng et al in Fig.1 does not disclose the limitation of the claim 38. However, Cheng et al discloses wherein an uppermost extent of the trench has a neck region (upper portion of 204) with sidewalls that are spaced apart by a first distance (Fig.2A) and the trench has a body region with sidewalls that are spaced apart by a second distance that is greater than the first distance (Fig.2A). It would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify Fig.1 of Chen et al according the teachings of the Fig.2A of Cheng et al, such that trench has a neck region having smaller distance between it’s sidewalls, in order to maximize the size of the pixels, in order to improve the picture quality.
With respect to claim 39, wherein the isolation filler structure extends out of the trench above the neck region and over lateral surfaces of the substrate (Fig.2A) over the adjacent image sensing elements (Fig.2A).
With respect to claim 40, Mouli discloses wherein the light absorbing layer terminates at an uppermost extent of the neck region and does not extend over the lateral surfaces of the substrate (Fig.14).
With respect to claim 41, Kusukawa in view of Mouli discloses wherein the light absorbing layer comprises germanium, titanium nitride, aluminum oxide (Para 20, para 48), or a silicon-germanium alloy.
With respect to claim 42, Kusukawa discloses further comprising: a high-k dielectric layer (Para 20, tantalum oxide) along sidewalls of the doped isolation layer.
With respect to claim 43, the arts cited above do not explicitly disclose further comprising: an air gap in a central region of the trench, the air gap defined by inner sidewalls of the isolation filler structure. However, it would have been obvious to one of ordinary skill in the art at time of the filing of the invention to have an airgap in the trench isolation structure in a central region of the trench, in order to reduce the parasitic capacitance and saving cost by using less material.
Allowable Subject Matter
Claims 44-48 are allowed.
The following is the reason for allowance of the claim 44, pertinent arts do not alone or in combination disclose: 44. (New) An integrated chip (IC), comprising: a substrate comprising silicon; a plurality of image sensing elements disposed in the substrate, the plurality of image sensing elements comprising a first doping type; trenches disposed within the substrate between adjacent image sensing elements of the plurality of image sensing elements, the trenches defined by inner sidewalls of the substrate; an isolation filler structure disposed within a trench; a light absorbing layer disposed within the trench along outer sidewalls of the isolation filler structure; a diffusion enhancement layer disposed within the trench along outer sidewalls of the light absorbing layer; an insulating layer disposed within the trench along outer sidewalls of the diffusion enhancement layer; a doped isolation layer disposed within the trench along outer sidewalls of the insulating layer; wherein the substrate includes a dopant diffusion region extending from the doped isolation layer into the substrate and a light absorbing material diffusion region extending from the doped isolation layer into the substrate, the light absorbing material diffusion region extending a shorter distance into the substrate than the dopant diffusion region; and wherein the dopant diffusion region comprises a concentration profile of a second doping type, opposite the first doping type, that decreases from about 1019 atoms per cubic centimeter or greater adjacent the doped isolation layer to about 5 x 1017 atoms per cubic centimeter or less at an outer edge of the dopant diffusion region, and the light absorbing material diffusion region comprises a molar ratio profile of a light absorbing material that decreases from about 3% or greater adjacent the doped isolation layer to about 0% at an outer edge of the light absorbing material diffusion region.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Li et al (US Pub No. 20200243582), Cheng et al (US Patent No. 9799702), Marty et al (US Pub No. 20110108939), Lim et al (US Pub No. 20060148194).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALI N NARAGHI whose telephone number is (571)270-5720. The examiner can normally be reached 10am-6pm.
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/ALI NARAGHI/Primary Examiner, Art Unit 2817
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