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.
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.
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.
Claim(s) 1-3, 5-15, & 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Huang et al. (US 2022/0115421) [Hereinafter Huang] & Takahashi et al (WO2020122032A1) [Hereinafter Takahashi].
Regarding claim 1, Huang teaches A photodetection device comprising:
a plurality of pixels [fig. 5B, pixel regions 402a/402b/402c, para 56] each having a photoelectric conversion region [fig. 5B, photodiode 406, para 56];
an on-chip microlens [fig. 5B, microlens 424, para 60] formed corresponding to each pixel (fig. 5B, 402a/402b/402c),
wherein the on-chip microlens (fig. 5b, 424) has a second refractive index [para 60; wherein the microlens comprises a transparent material, dielectric material, or another type of material] and
a gap [fig. 5B, gaps between microlenses 424] having a tapered cross-sectional shape is formed as a region separating on-chip microlenses [fig. 5B; wherein the gaps are tapered].
Huang fails to explicitly disclose wherein the on-chip microlens has a second refractive index that is a refractive index higher than a first refractive index.
However, Takahashi teaches wherein the on-chip microlens has a second refractive index [fig. 1, first microlens layer 20, wherein the first microlens layer is silicon nitride; “The first microlens layer has a thickness of 150 nm or more and 400 nm or less, a refractive index of 1.75 or more and 2.15 or less, and silicon nitride”] that is a refractive index higher than a first refractive index [fig. 1, second microlens layer 21; “the second microlens layer is made of . . .silicon oxide having a lower refractive index than the first microlens layer.”].
Therefore it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention for the microlens to comprise a higher refractive index layer closest to the pixel to improve light gathering efficiency and reduce optical crosstalk.
Regarding claim 2, Huang/Takahashi teaches The photodetection device according to claim 1,
wherein the gap has a tapered shape [Huang, fig. 5, wherein the gap between the microlenses 424 are tapered] that narrows toward a surface of a semiconductor substrate [Huang, fig. 5B, substrate 404, para 31] on which the photoelectric conversion region (Huang, fig. 5B, 406) is formed.
Regarding claim 3, Huang/Takahashi teaches The photodetection device according to claim 1,
wherein the first refractive index is 1.6 (Takahashi, “the refractive index of the second microlens layer 21 is preferably lower than that of the first microlens layer 20, for example, 1.4 or more and 1.75 or less.”], and
the second refractive index is a refractive index higher than 1.6 [Takahashi, fig. 1, first microlens layer 20, wherein the first microlens layer is silicon nitride; “The first microlens layer has a thickness of 150 nm or more and 400 nm or less, a refractive index of 1.75 or more and 2.15 or less, and silicon nitride”].
Regarding claim 5, Huang/Takahashi teaches The photodetection device according to The photodetection device according to claim 2,
wherein the gap [Huang, fig. 5B, gaps between microlenses 424] does not reach the surface of the semiconductor substrate (Huang, fig. 5B, 404) in a cross-sectional view.
Regarding claim 6, Huang/Takahashi teaches The photodetection device according to claim 1,
wherein the gap is filled with air or an embedded film [Huang, fig. 5C, dielectric film 426, para 60].
Regarding claim 7, Huang/Takahashi teaches The photodetection device according to claim 1, wherein an entire periphery of the on-chip microlens (Huang, fig. 5B, 424) is surrounded by the gap in a plan view [Huang, fig. 5B; wherein the gap surrounds both sides of the microlens 424].
Regarding claim 8, Huang/Takahashi teaches The photodetection device according to claim 1,
wherein the on-chip microlens has a part that does not become the gap in a diagonal direction in a plan view [Huang, fig. 5B; wherein the microlens 424 has portions that are not part of the gap],
and has the gap in four directions of upper, lower, left, and right directions [Huang, fig. 5B; wherein the gap extends in all four directions].
Regarding claim 9, Huang/Takahashi teaches The photodetection device according to claim 1,
wherein a first layer that suppresses reflection of incident light [Huang, fig. 5B, oxide layer 408, para56; wherein para 26 defines exemplary materials for oxide layers] is formed on a surface of a semiconductor substrate [Huang, fig. 5B, substrate 404, para 45] on which the photoelectric conversion region (Huang, fig. 5B, 406) is formed.
Regarding claim 10, Huang/Takahashi teaches The photodetection device according to claim 9,
wherein the first layer (Huang, fig. 5B, 408) has a moth-eye structure or a recess having a predetermined shape in a plan view [Huang, fig. 5B illustrates recess shape of layer 408].
Regarding claim 11, Huang/Takahashi teaches The photodetection device according to claim 10,
wherein the predetermined shape is a cross shape [Huang, fig. 5B; wherein layer 408 has a capital “T” cross shape].
Regarding claim 12, Huang/Takahashi teaches The photodetection device according to claim 1,
wherein a second layer [Huang, fig. 5B, antireflective coating 410, para 56] is formed between a semiconductor substrate (Huang, fig. 5B, 404) on which the photoelectric conversion region (Huang, fig. 5B, 406) is formed and the on-chip microlens (Huang, fig. 5B, 424).
Regarding claim 13, Huang/Takahashi teaches The photodetection device according to claim 12,
wherein the gap does not penetrate the second layer (Huang, fig. 5B, 410) in a cross- sectional view [Huang, fig. 5B].
Regarding claim 14, Huang/Takahashi teaches The photodetection device according to claim 1,
wherein a light-shielding film [Huang, fig. 5B, color filter layer 412, para 57] that shields adjacent on-chip microlenses (Huang, fig. 5B, 424) from incident light is formed.
Regarding claim 15, Huang/Takahashi teaches The photodetection device according to claim 14,
wherein the gap does not penetrate the light-shielding film (Huang, fig. 5B, 412) in a cross-sectional view.
Regarding claim 18, Huang teaches The photodetection device according to claim 1.
Huang fails to explicitly disclose wherein the on-chip microlens uses amorphous silicon (a-Si), silicon nitride (SiN), a high refractive index resin, tantalum (Ta), titanium (Ti), aluminum oxide (AlO), or a high refractive index metal oxide film as a material.
However, Takahashi teaches wherein the on-chip microlens uses amorphous silicon (a-Si), silicon nitride (SiN), a high refractive index resin, tantalum (Ta), titanium (Ti), aluminum oxide (AlO), or a high refractive index metal oxide film as a material [fig. 1, microlens 200, “silicon nitride is used as a material for the microlens 200”].
Therefore it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention for the microlens to comprise silicon nitride to bend the light more aggressively to enable tighter focusing into smaller pixels.
Regarding claim 19, Huang/Takahashi teaches The photodetection device according to claim 1,
wherein the photodetection device is configured as an image sensor that supports near-infrared rays [Huang, para 29, “the color filter layer may be omitted from a near infrared (NIR) pixel region to permit near infrared light to pass into the associated photodiode”].
Regarding claim 20, Huang/Takahashi teaches An electronic device on which a photodetection device is mounted, the photodetection device comprising:
a plurality of pixels [Huang, fig. 5B, pixel regions 402a/402b/402c, para 56] each having a photoelectric conversion region[Huang, fig. 5B, photodiode 406, para 56]; and
an on-chip microlens [Huang, fig. 5B, microlens 424, para 60] formed corresponding to each pixel (Huang, fig. 5B, 402a/402b/402c),
wherein the on-chip microlens (Huang, fig. 5b, 424) has a second refractive index [para 60; wherein the microlens comprises a transparent material, dielectric material, or another type of material] and
a gap having a tapered cross-sectional shape [Huang, fig. 5B, gaps between microlenses 424] is formed as a region separating on-chip microlenses [Huang, fig. 5B, microlens 424, para 60].
Huang fails to explicitly disclose wherein the on-chip microlens has a second refractive index that is a refractive index higher than a first refractive index.
However, Takahashi teaches wherein the on-chip microlens has a second refractive index [fig. 1, first microlens layer 20, wherein the first microlens layer is silicon nitride; “The first microlens layer has a thickness of 150 nm or more and 400 nm or less, a refractive index of 1.75 or more and 2.15 or less, and silicon nitride”] that is a refractive index higher than a first refractive index [fig. 1, second microlens layer 21; “the second microlens layer is made of . . .silicon oxide having a lower refractive index than the first microlens layer.”].
Therefore it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention for the microlens to comprise a higher refractive index layer closest to the pixel to improve light gathering efficiency and reduce optical crosstalk.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Huang & Takahashi as applied to claims 1-3, 5-15, & 18-20 and further in view of Nasukawa et al. (JPH08328002A).
Regarding claim 4, Huang/Takahashi teaches The photodetection device according to claim 2.
Huang/Takahashi fails to explicitly disclose wherein the gap penetrates to the surface of the semiconductor substrate in a cross-sectional view.
However, Nasukawa teaches wherein the gap penetrates to the surface of the semiconductor substrate in a cross-sectional view [para 39; wherein the gap between the microlens penetrates the microlens array substrate 202].
Therefore it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention for the gap to penetrate the substrate to reduce optical cross talk by preventing stray light from bleeding into adjacent pixels.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Huang & Takahashi as applied to claims 1-3, 5-15, & 18-20 and further in view of Yun (CN101221964A).
Regarding claim 16, Huang/Takahashi teaches The photodetection device according to claim 2.
Huang/Takahashi fails to explicitly disclose wherein, when a width of a lower portion of the gap is 100 nm, a width of an upper portion of the gap is larger than 100 nm.
However Yun teaches wherein, when a width of a lower portion of the gap is 100 nm, a width of an upper portion of the gap is larger than 100 nm [“the groove 154 is formed to have the same width or a slightly wider width w than the gap 252 . . . The width w of the trench 154 may be about 100 nm to 400 nm or less”].
Therefore it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention for the gap to have widths of 100nm to 400nm or less to prevent optical cross-talk enhancing performance of the device.
Allowable Subject Matter
Claim 17 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 a statement of reasons for the indication of allowable subject matter:
Regarding claim 17, Huang/Takahashi teaches The photodetection device according to claim 2,
wherein the second refractive index is 1.9 [Takahashi, fig. 1, first microlens layer 20, wherein the first microlens layer is silicon nitride; “The first microlens layer has a thickness of 150 nm or more and 400 nm or less, a refractive index of 1.75 or more and 2.15 or less, and silicon nitride”].
The prior art of record fails to explicitly disclose the gap has a side wall having an angle at which incident light is totally reflected at an incident angle of 32º.
Thereby claim 17 contains allowable subject matter and would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to FELIX B ANDREWS whose telephone number is (703)756-1074. The examiner can normally be reached Monday - Friday 8:00 am - 5:00 pm ET.
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/FELIX B ANDREWS/Examiner, Art Unit 2812
/William B Partridge/Supervisory Patent Examiner, Art Unit 2812
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