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 .
Specification
The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed.
The following title is suggested: PIXEL SENSOR ARRAY WITH MULTILAYER LIGHT DIFFUSION STRUCTURE AND METHODS OF FORMATION
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.
(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 1, 3, and 7 are rejected under 35 U.S.C. 102 (a)(2) as being anticipated by Noudo; Shinichiro et al. (US 2025/0120206; hereinafter Noudo).
Regarding claim 1, Noudo discloses a pixel sensor, comprising:
a photodiode (212; Figs 5,29; ¶ [0138,0155,0232-233]) in a substrate (209; Figs 5,29; ¶ [0135-137]);
a first plurality of diffusion structures (the projections of insulating film 207 into recesses in 212/209 substrate, which together constitute diffraction/scattering element 219; Fig 29; ¶ [0233]; see the annotated figure below;) extending into a portion of the substrate above the photodiode; and
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a second plurality of diffusion structures (pillars 203, which constitute 2001; Fig 5; ¶ [0136,0155-156]) above the first plurality of diffusion structures,
wherein the second plurality of diffusion structures extend into a dielectric layer (filler material 201, which may be comprised of a fluorine-containing siloxane-based resin or other dielectric; Fig 5; ¶ [0136,0161,0174,0215]) above the substrate.
Regarding claim 3, Noudo discloses the pixel sensor of claim 1, wherein a first material composition of the first plurality of diffusion structures (207, composed of SiO2; ¶ [0143]) and a second material composition of the second plurality of diffusion structures (203, composed of amorphous silicon; ¶ [0149], claim 6) are different material compositions.
Regarding claim 7, Noudo discloses the pixel sensor of claim 1, further comprising:
a third plurality of diffusion structures (2002; Fig 5; ¶ [0155-156]) above the second plurality of diffusion structures,
wherein the third plurality of diffusion structures extend into another dielectric layer (2151; Fig 5; ¶ [0155-156, 0215]) above the dielectric layer.
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.
Claims 2, 4-6, 8, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Noudo; Shinichiro et al. (US 2025/0120206; hereinafter Noudo).
Regarding claim 2, Noudo discloses the pixel sensor of claim 1, but does not specifically discloses in the same embodiment wherein a first quantity of diffusion structures in the first plurality of diffusion structures and a second quantity of diffusion structures in the second plurality of diffusion structures are different quantities of diffusion structures; however, a number of configurations are depicted in additional figures and description throughout the document, and correspondingly such arrangement would have been obvious to a person having ordinary skill in the art. For example, Fig 5 of the cited embodiment depicts a cross section having 5 diffusion structures 207 of the first plurality across one photodiode and Fig 29 depicts a 5 by 5 array of the first plurality diffusion structures 207, while Fig 5 depicts 9 pillars 203 of the second plurality of diffusion structures across one photodiode, though quantities are not stated. In other examples, the second plurality in shown in varying quantities (see, for example, Figs 4,10,33-36 and others). One may have been motivated to configure the pixel sensor of claim 1 in this manner in order to accommodate incident light arriving from different angles of view (or image height, as used by Noudo); for example, a 10 by 10 pillar array of a second plurality is disclosed for pixel 1 in reference to Figs 8-10 (¶ [0177-178, 0281-282]).
Regarding claim 4, Noudo discloses the pixel sensor of claim 3, wherein a first refractive index of a material composition of the first plurality of diffusion structures and a second refractive index of a material composition of the second plurality of diffusion structures are different refractive indexes. (It would have been obvious to a person having ordinary skill in the art the a refractive index of SiO2 and a refractive index of amorphous silicon are different, and is easily found in a material reference.)
Regarding claim 5, Noudo discloses the pixel sensor of claim 1, but does not specifically disclose wherein a first vertical thickness of a diffusion structure of the first plurality of diffusion structures and a second vertical thickness of a diffusion structure of the second plurality of diffusion structures, are different vertical thicknesses; however, such configuration would have been obvious to a person having ordinary skill in the art. Noudo discloses the first plurality of diffusion structures 219 as a regular arrangement of recesses and projections (Fig 29; ¶ [0233]), and at least implies that each diffusion structure of the 219 first plurality of diffusion structures has an equal first vertical thickness. In contract, pillars 203 of the second plurality of diffusion structures are described as being optimized for a particular angle of incidence (image height, as used by Nuodo; ¶ [0119])), and further each pillar 203 of a plurality of pillars may have a different height (vertical thickness) to accommodate a different angle of incidence (¶ [0008,096,0150]). Therefore, at least in consideration that each of the 203 pillars within the second plurality of diffusion structures may have a different height from one another, then at least some of the diffusion structures of the second plurality have a different second vertical thickness from the first vertical thickness.
Regarding claim 6, Noudo discloses the pixel sensor of claim 1, but does not specifically disclose wherein a first lateral width of a diffusion structure of the first plurality of diffusion structures, and a second lateral width of a diffusion structure of the second plurality of diffusion structures, are different lateral widths; however, such configuration would have been obvious to a person having ordinary skill in the art. Noudo discloses the first plurality of diffusion structures 219 as a regular arrangement of recesses and projections (Fig 29; ¶ [0233]), and at least implies that each diffusion structure of the 219 first plurality of diffusion structures has an equal first lateral width. In contrast, Nuodo discloses that the pillars 203 which constitute the second plurality of diffusion structures 2001 may have different pitches or shapes (lateral widths, at least as depicted by the differing diameters of 203 in Fig 4; ¶ [0150]). It would have been obvious, since each 203 may have a different lateral width from one another, that at least some of the diffusion structures 203 of the second plurality have a different lateral width than a first lateral width of the first plurality of diffusion structures 219. Nuodo discloses a different function for the second plurality of diffusion structures (to guide each principal ray that is incident at a different angle; ¶ [0008]) than for the first plurality of diffusion structures (to increase an optical path length within a photoelectric converting section (¶ [0233]), which is the reason for the different configurations of lateral widths between them.
Regarding claim 8, Noudo discloses a pixel sensor array, comprising:
a photodiode (212; Figs 5,29; ¶ [0138,0155,0232-233]) in a substrate (209; Figs 5,29; ¶ [0135-137]);
a first plurality of diffusion structures (the projections of insulating film 207 into recesses in 212/209 substrate, which together constitute diffraction/scattering element 219; Fig 29; ¶ [0233]; see the annotated figure below;) extending into a portion of the substrate above the photodiode,
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a deep trench isolation (DTI) structure (trench of Fig 28B, in place of 213 {Fig 5; ¶ [0138]}; ¶ [0225,0227]) extending into the substrate and laterally surrounding the first plurality of diffusion structures and at least a portion of the photodiode;
a second plurality of diffusion structures (pillars 203, which constitute 2001; Fig 5; ¶ [0136,0155-156]) above the first plurality of diffusion structures,
wherein the second plurality of diffusion structures extend into a dielectric layer (filler material 201, which may be comprised of a fluorine-containing siloxane-based resin or other dielectric; Fig 5; ¶ [0136,0161,0174,0215]) above the substrate.
Nuodo does not disclose in the same embodiment, a grid structure above the DTI structure and laterally surrounding the second plurality of diffusion structures; however, Nuodo discloses in Fig 6 {¶ [0159-160]} a grid structure above a DTI structure (openings in 2003 in trench shapes between pixels 100 which penetrate filler material 201-1]) and laterally surrounding a second plurality of diffusion structures (2003). Accordingly, it would have been obvious to a person having ordinary skill in the art to have combined the grid structure of Fig 6 with the diffusion structures of Fig 5. One may have been motivated do to this in order to combine the ability to guide light near the pixel boundary (Fig 6; ¶ [0160]) with an avoidance of pattern collapse (Fig 5; ¶ [0157]) at the same time. One would have had a reasonable expectation of success because of the similarity in the structures, and because Nuodo has disclosed this combination in claim 24 (light guiding sections).
Regarding claim 13, Noudo discloses the pixel sensor array of claim 8, further comprising:
a third plurality of diffusion structures (2002; Fig 5; ¶ [0155-156]) above the second plurality of diffusion structures,
wherein the third plurality of diffusion structures extend into another dielectric layer (2151; Fig 5; ¶ [0155-156, 0215]) above the dielectric layer.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Noudo; Shinichiro et al. (US 2025/0120206; hereinafter Noudo) in view Takeuchi; Koichi et al. (US 2026/0059899; hereinafter Takeuchi).
Regarding claim 9, Noudo discloses the pixel sensor array of claim 8, wherein the first plurality of diffusion structures (219; Fig 29) have an approximately V-shaped cross-sectional profile (shown in Figs 5,29) but does not disclose wherein the second plurality of diffusion structures (2001; Fig 1) have an approximately U-shaped cross-sectional profile.
In the same field of endeavor, Takeuchi discloses a similar pixel sensor array, wherein a first plurality of diffusion structures have an approximately V-shaped cross-sectional profile (Figs 105A-B; ¶ [0491-492]); and wherein a second plurality of diffusion structures (62; Figs 55-56; ¶ [0395-397]) have an approximately U-shaped cross-sectional profile. Accordingly, it would have been obvious to a person having ordinary skill in the art to have substituted the plurality of diffusion structures having an approximately U-shaped cross-section profile and associated dielectric layer (53; Fig 55; ¶ [0296,0396]) of Takeuchi for the second plurality of diffusion structures and associated fill layer of Nuodo. One may have been motivated to do this in order to suppress light reflection from the diffusion structures for different incident angles of light (¶ [0383-384]). One would have had a reasonable expectation of success because of the similar endeavors, structures, and materials of Nuodo and Takeuchi, and because of the various alternate diffusion structure configurations disclosed by Takeuchi throughout the document for a similar purpose.
Allowable Subject Matter
Claims 16-20 allowed.
The following is a statement of reasons for the indication of allowable subject matter:
Regarding claims 16-20, the prior art of record, either singularly or in combination, does not disclose or suggest the combination of limitations including “forming a first plurality of recesses in the substrate above the photodiode; forming a first dielectric layer above the substrate such that first dielectric regions of the first dielectric layer fill in the first plurality of recesses to form a first plurality of diffusion structures in the first plurality of recesses; forming a second plurality of recesses in the first dielectric layer above the first plurality of diffusion structures; and forming a second dielectric layer above the first dielectric layer such that second dielectric regions of the second dielectric layer fill in the second plurality of recesses to form a second plurality of diffusion structures in the second plurality of recesses”.
The prior art Noudo and the prior art Takeuchi each disclose a method of forming a first plurality of diffusion structures in recesses in a substrate and a second plurality of diffusion structures above the first plurality of diffusion structures. However, none of Nuodo, Takeuchi, and other prior art reviewed by the Examiner disclose forming a second plurality in recesses in the same dielectric layer which fills a first plurality of recesses which constitute a first plurality of diffusion structures, and filling the second plurality of recesses with another dielectric layer to form a second plurality of diffusion structures.
Claims 10-12, and 14-15 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 a statement of reasons for the indication of allowable subject matter:
Regarding claims 10-12, the prior art of record, either singularly or in combination, does not disclose or suggest the combination of limitations including “wherein a refractive index of the dielectric layer is different at a bottom of the dielectric layer than at a top of the dielectric layer”. The prior art Takeuchi discloses a reflection suppressing layer on one end of a pillar, the reflection suppressing layer and pillar together constituting a diffusion structure which extends into a dielectric layer, wherein a refractive index of the reflection suppressing layer is different from that of the pillar and therefore a refractive index of the diffusion structure is different at a bottom that at a top. Takeuchi further discloses the reflection suppressing layer may have a gradient from one end to the other. However, Takeuchi nor any prior art found by the Examiner disclose a dielectric layer into which a diffusion structure extends has a refractive index which is different at a bottom than at a top, in combination with the additional limitations of the base claim.
Regarding claims 14-15, the prior art of record, either singularly or in combination, does not disclose or suggest the combination of limitations including “wherein a first quantity of diffusion structures in the second plurality of diffusion structures is greater than a second quantity of diffusion structures in the third plurality of diffusion structures”, in combination with the base and intervening claims.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Nuodo; Shinichiro et al. (US 2025/0120205; the prior art discloses a pixel sensor array with light diffusion structures and methods of manufacturing);
Arbabi; Amir et al. (US 2019/0191144; the prior art discloses an image sensor with multilayer light diffusion structures);
Tsao; Tsun-Kai et al. (US 2021/0272996; prior art discloses an image sensor having an absorption enhancement structure with curved sidewalls, and methods of forming).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRAD KNUDSON whose telephone number is (703)756-4582. The examiner can normally be reached Telework 9:30 -18:30 ET; M-F.
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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.
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/B.A.K./Examiner, Art Unit 2817
/ELISEO RAMOS FELICIANO/Supervisory Patent Examiner, Art Unit 2817
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