Allowable Subject Matter
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 filed on 11/29/2023 has been considered.
Drawings
The drawings filed on 11/29/2023 are acceptable.
Specification
The abstract of the disclosure and the specification filed on 11/29/2023 are acceptable.
Claim Rejections - 35 USC § 102
(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.
Claim(s) 1-4, 8, 9, 11, 13, 14, 17-19 is/are rejected under 35 U.S.C. 102a1 as being anticipated by Mabuchi (US 10,741,593).
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Regarding claim 1, Mabuchi discloses:
An image sensor, comprising:
a substrate (column 3 line 62) having a front surface and a back surface;
a photodiode (102, column 3 line 61) formed in the substrate;
a charge transfer transistor (110, column 4 lines 5-11 disclose the storage gate comprises a pair of charge transfer transistors 110. ) coupled to the photodiode (102) and formed in the front surface of the substrate;
a storage gate (106, column 4 lines 10-15) coupled between the photodiode (102) and the charge transfer transistor (110), wherein the storage gate (106) comprises a trench transistor formed in the front surface of the substrate (column 7 lines 21-35);
and
a deep trench isolation structure (316, column 8 line 63- column 9 line 10) formed in the back surface of the substrate (330, column 8 line 63- column 9 line 10) wherein the deep trench isolation structure (316) is laterally aligned with the storage gate (306, figure 3a).
Regarding claim 2, Mabuchi further discloses:
wherein the deep trench isolation structure is filled with light-shielding material (column 8 line 63- column 9 line 10).
Regarding claim 3, Mabuchi further discloses:
The image sensor of claim 2, wherein the light-shielding material comprises metal (column 9 lines 14-16).
Regarding claim 4, Mabuchi further discloses:
wherein the storage gate (306) comprises:
a gate conductor (SG, figure 3a) formed in a trench;
a buried channel region (308, column 11, 30-45) at least partially surrounded by the trench; and
a gate insulating layer (332, column 11 line 27) between the gate conductor (SG) and the buried channel region (308).
Regarding claim 8, Mabuchi further discloses:
wherein the charge transfer transistor comprises a planar transistor formed at the front surface of the substrate (column 5 lines 25-28).
Regarding claim 9, Mabuchi further discloses:
wherein the charge transfer transistor comprises an additional trench transistor having a similar structure as the storage gate (column 4 lines 7-15).
Regarding claim 11, Mabuchi further discloses:
wherein the storage gate has a first footprint and wherein the deep trench isolation structure has a second footprint that is larger than the first footprint (figure 3a).
Regarding claim 13, Mabuchi discloses:
A method of manufacturing an image sensor, comprising:
obtaining a substrate (column 3 line 62) having a front surface and a back surface;
etching a trench in the front surface of the substrate (column 7 line 60);
implanting a potential well (308) in a region of the substrate at least partially surrounded by the trench;
growing a gate oxide layer (322) in the trench;
depositing conductive gate material (SG) into the trench; and
forming a deep trench isolation structure (316) in the back surface of the substrate, wherein the deep trench isolation structure is aligned with the trench (figure 3a).
Regarding claim 14, Mabuchi further discloses:
filling the deep trench isolation structure with light-blocking material (column 8 line 63- column 9 line 10).
Regarding claim 17, Mabuchi discloses:
An image sensor pixel, comprising:
a substrate (column 3 line 62) having an upper surface and a lower surface;
a trench transistor (SG, 106) formed in the upper surface; and
a deep trench isolation structure (316) formed in the lower surface, wherein the deep trench isolation structure at least partially covers the trench transistor from the lower surface.
Regarding claim 18, Mabuchi further discloses:
wherein the trench transistor (SG, 106) comprises a global shutter storage gate (column 7 lines 15-30).
Regarding claim 19, Mabuchi further discloses:
a photodiode (202) formed in the substrate; and
a floating diffusion region (FD 118 in figure 1, 218 in column 5 lines 45-52) formed in the substrate, wherein the trench transistor (106) comprises a charge transfer transistor (110) coupled between the photodiode (PD) and the floating diffusion region (FD 118, figure 1).
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) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mabuchi.
Regarding claim 10, Mabuchi does not disclose “wherein the storage gate has a first footprint and wherein the deep trench isolation structure has a second footprint that is identical to the first footprint”. However, a change in size or shape or both is an unpatentable modification when it results in optimum conditions that differ from the prior art in degree but not in kind. In Re Rose, 220 F.2d 459, 105 USPQ 237, In reDailey, 357 F.2d 669, 149 USPQ 47). In the instant case the prior art device would not perform differently if modified to the claimed shape or size. Therefore the claimed limitations are considered met.
Allowable Subject Matter
Claims 5-7, 12, 15, 16, 20 are 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.
Regarding claim 5, the prior art does not disclose “a source follower transistor coupled to the charge transfer transistor and formed at the front surface of the substrate; and a charge isolation well between the photodiode and the source follower transistor” in combination with the remaining claimed features.
Regarding claim 7, the prior art does not disclose “wherein the photodiode has a portion that extends into a region between the storage gate and the deep trench isolation structure” in combination with the remaining claimed features.
Regarding claim 12, the prior atrt does not disclose “a color filter element formed on the back surface of the substrate; and a microlens formed on the color filter element and configured to focus incoming light away from the storage gate” in combination with the remaining claimed features.
Regarding claim 15, the prior art does not disclose”forming planar transistors at the front surface of the substrate; forming a photodiode region in the substrate; and forming an isolation well between the photodiode region and the planar transistors” in combination with the remaining claimed features.
Regarding claim 16, the prior att does not disclose “forming a row select transistor at the front surface of the substrate; and forming a source follower transistor at the front surface of the substrate, the source follower transistor being at least 50% wider than the row select transistor” in combination with the remaining claimed features.
Regarding claim 20, the prior art does not disclose “a photodiode region laterally surrounded by the deep trench isolation structure, wherein the photodiode region has a portion that extends into a region of the substrate between the trench transistor and the deep trench isolation structure” in combination with the remaining claimed features.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to WILLIAM A HARRISTON whose telephone number is (571)270-3897. The examiner can normally be reached Mon-Fri, 9AM-5PM.
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/WILLIAM A HARRISTON/Primary Examiner, Art Unit 2899