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 .
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). The certified copies have been filed in Korean Patent Application No. 10-2023-0096675, filed on 7/25/2023, and Korean Patent Application No. 10-2024-0074097, filed on 6/6/2024
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statement (IDSs) submitted on 4/23/2025 and 10/28/2025 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
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 title of the invention has been suggested as, “AVALANCHE PHOTODETECTION ELEMENT, PHOTODETECTOR, AND ELECTRONIC DEVICE FOR TIME-OF-FLIGHT MEASUREMENT”.
Claim Objections
Claims 16-19 are objected to because of the following informalities:
The preambles of claim 16-19, which depend on claim 15, refer to a “photodetection element”, whereas the preamble of claim 15 refers to a “photodetector”. The preambles of dependent claims should match the preamble of the parent claim. Therefore, “photodetection element” in preambles of claims 16-19 should be changed to “photodetector”.
Appropriate correction is required.
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)(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, 15, and 18 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Teva (US 2016/0035929 A1).
Regarding claim 1, Teva teaches a photodetection element (single-photon avalanche diode, Figs. 3-4, [0043]-[0044]) comprising:
a substrate (comprising substrate 1 and epitaxial layer 2, Fig. 3, [0037]) having a first surface (top surface of the epitaxial layer 2, Fig. 3) and a second surface (bottom surface of the substrate 1, Fig. 3 (the bottom surface is not shown in Fig. 3)) opposite to each other;
a first node region (comprising layers in trench 3, Fig. 3, [0038]) within the substrate (comprising substrate 1 and epitaxial layer 2, Fig. 3) and having a first conductivity type (corresponds to second type of electrical conductivity in Teva; [0043]: “the trench 3 is completely filled with doped polysilicon of the second type of electric conductivity.”);
a second node region (comprising contact well 6, Fig. 3, [0040]) within the substrate (comprising substrate 1 and epitaxial layer 2, Fig. 3) spaced apart from the first node region (comprising layers in trench 3, Fig. 3) and having a second conductivity type (corresponds to first type of electrical conductivity in Teva [0054]: “first type of electric conductivity”) different from the first conductivity type (second type of electrical conductivity in Teva); and
an avalanche multiplication region (junction region 14, Fig. 3, [0039]: ”During an operation of the single-photon avalanche diode the junction region 14 is a region of high electric field strength.”, and therefore junction region 14 is the avalanche multiplication region) formed between the first node region (comprising layers in trench 3, Fig. 3) and the second node region (comprising contact well 6, Fig. 3),
wherein the first node region (comprising layers in trench 3, Fig. 3), the avalanche multiplication region (junction region 14, Fig. 3), and the second node region (comprising contact well 6, Fig. 3) are arranged along a first direction (horizontal direction in Fig. 3) parallel to the first surface (top surface of the epitaxial layer 2, Fig. 3).
Regarding claim 2, Teva teaches the photodetection element (single-photon avalanche diode, Figs. 3-4) of claim 1, wherein the second node region (comprising contact well 6, Fig. 4) is configured to surround the first node region (comprising layers in trench 3, Fig. 4 (see sidewalls 38 of the trench 3 in Figs. 3-4)).
Regarding claim 3, Teva teaches the photodetection element (single-photon avalanche diode, Figs. 3-4) of claim 1, the first node region (comprising layers in trench 3, Fig. 3) and the second node region (comprising contact well 6, Fig. 3) extend along a second direction (vertical direction, Fig. 3: both structures extend into the epitaxial layer 2 along the vertical direction) intersecting the first direction (horizontal direction, Fig. 3).
Regarding claim 15, Teva teaches a photodetector (single-photon avalanche diode, Figs. 3-4) comprising a photodetection element (comprising the layers in the substrate 1 and epi-layer 2, Figs. 3, [0037]) , a connection layer (embedded metal layers 10 within the dielectric 9, Fig. 3, [0041]) and an optical element layer (antireflection coating 12 and/or at least one filter layer 13, Fig. 3, [0041]) that transmits incident light (incidence of radiation 15, Fig. 3) to the photodetection element (comprising the layers in the substrate 1 and epi-layer 2, Figs. 3),
wherein the photodetection element (comprising the layers in the substrate 1 and epi-layer 2, Figs. 3) includes, a substrate (comprising substrate 1 and epitaxial layer 2, Fig. 3) having a first surface (top surface of the epitaxial layer 2, Fig. 3) and a second surface (bottom surface of the substrate 1, Fig. 3 (the bottom surface is not shown in Fig. 3)) on opposite sides of each other, a first node region (comprising layers in trench 3, Fig. 3) provided in the substrate (comprising substrate 1 and epitaxial layer 2, Fig. 3) and having a first conductivity type (corresponds to second type of electrical conductivity in Teva; [0043]: “the trench 3 is completely filled with doped polysilicon of the second type of electric conductivity.”), a second node region (comprising contact well 6, Fig. 3, [0040]) spaced apart from the first node region (comprising layers in trench 3, Fig. 3) in the substrate (comprising substrate 1 and epitaxial layer 2, Fig. 3) and having a second conductivity type (corresponds to first type of electrical conductivity in Teva [0054]: “first type of electric conductivity”) different from the first conductivity type (second type of electrical conductivity in Teva), and an avalanche multiplication region (junction region 14, Fig. 3, [0039]: ”During an operation of the single-photon avalanche diode the junction region 14 is a region of high electric field strength.”, and therefore junction region 14 is the avalanche multiplication region) formed between the first node region (comprising layers in trench 3, Fig. 3) and the second node region (comprising contact well 6, Fig. 3),
wherein the first node region (comprising layers in trench 3, Fig. 3), the avalanche multiplication region (junction region 14, Fig. 3), and the second node region (comprising contact well 6, Fig. 3) are arranged along a first direction (horizontal direction, Fig. 3) parallel to the first surface,
wherein the connection layer (embedded metal layers 10 within the dielectric 9, fig. 3) includes conductive lines (metal lines of the metal layers 10, Fig. 3) electrically connected (through vertical connections 11, Fig. 3, [0041]) to at least one of the first node region (comprising layers in trench 3, Fig. 3) and the second node region (comprising contact well 6, Fig. 3).
Regarding claim 18, Teva teaches the photodetection element (Figs. 3-4) of claim 15, wherein the connection layer (embedded metal layers 10 within the dielectric 9, Fig. 3) and the optical element layer (antireflection coating 12 and/or at least one filter layer 13, Fig. 3) are sequentially disposed on the first surface (top surface of the epitaxial layer 2, Fig. 3).
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.
Claims 4-6 are rejected under 35 U.S.C. 103 as being unpatentable over by Teva (US 2016/0035929 A1) as applied to claims 1-3 above, and further in view of Webster (US 2013/0193546 A1).
Regarding claim 4, Teva teaches the photodetection element of claim 1,
wherein the first node region (comprising layers in trench 3, Fig. 3) includes:
a first contact region (contact region 5, Fig. 3, [0040]); and
a first well (semiconductor layer 4, Fig. 3, [0040]) provided between the first contact region (contact region 5, Fig. 3) and the second surface (bottom surface of the substrate 1, Fig. 3).
Teva, however, does not explicitly disclose that
the first well having a doping concentration lower than that of the first contact region.
Webster, on the other hand teaches a photodetection element (single-photon avalanche diode (SPAD), Fig. 7, [0113]), wherein
the first well (n-well, Fig. 7, [0114]) having a doping concentration lower (N-well vs N+-implant) than that of the first contact region (heavily doped n+ implant, Fig. 7, [0114]).
A person of ordinary skill in the art before the effective filing date of the claimed invention would already know that it is common in semiconductor devices to dope the contact region at a higher doping level than the adjacent regions, as taught by Webster ([0114]), to form a low resistivity contact interface to the semiconductor device. Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention would be motivated to have the contact region at a high doping level such that the first well has a doping concentration lower than that of the first contact region, so that a low resistivity contact can be made to the first well region.
Regarding claim 5, Teva in view of Webster teaches the photodetection element of claim 4, wherein,
Teva further teaches that in the first node region (comprising layers in trench 3, Fig. 3) extending along a second direction (vertical direction, Fig. 3) intersecting the first direction (horizontal direction, Fig. 3), a central portion of the first contact region (contact region 5, Fig. 3) and a central portion of the first well (semiconductor layer 4, Fig. 3) are arranged to overlap (see also Fig. 4).
Regarding claim 6, Teva in view of Webster teaches the photodetection element of claim 4, wherein,
Teva further teaches that in the first node region (comprising layers in trench 3, Fig. 3) extending along a second direction (vertical direction, Fig. 3) intersecting the first direction (horizontal direction, Fig. 3), the first well (semiconductor layer 4, Fig. 3) surrounds the first contact region (contact region 5, Fig. 3) and extends along the second direction (vertical direction, Fig. 3).
Claims 7-9 are rejected under 35 U.S.C. 103 as being unpatentable over by Teva (US 2016/0035929 A1) in view of Webster (US 2013/0193546 A1) as applied to claims 4-6 above, and further in view of Keshavarzian (Keshavarzian et al., "Low-noise high-dynamic-range single-photon avalanche diodes with integrated PQAR circuit in a standard 55nm BCD process", Proc. SPIE 12089, Advanced Photon Counting Techniques XVI, 120890B (30 May 2022); https://doi.org/10.1117/12.2618349).
Regarding claim 7, while Teva in view of Webster teaches the photodetection element of claim 4, wherein
Teva and Webster do not teach that the first node region further includes a first deep well provided between the first well and the second surface and having a doping concentration lower than that of the first contact region.
Keshavarzian, on the other hand, teaches the first node region (comprising P+ region, PW region and DPW region, Fig. 1(b); page 2, para. 1) further includes a first deep well (DPW, Fig. 1(b)) provided between the first well (PW region, Fig. 1 (b)) and the second surface (bottom surface of the p-Sub in Fig. 1 (b)) and having a doping concentration lower than that of the first contact region (heavily doped N+ implant region, Fig. 7: N+ vs N).
Keshavarzian teaches that DPW/BNW junction are used in order to form the deep SPAD (Fig. 1(b); page 2, para. 1), by determining the location of avalanche multiplication region. Notably, Teva also discloses that the location of the semiconductor layer 4 and the junction region 14 may be arranged in such a manner that the space charge region 31 is at a distance from the sidewall 38 of the trench 3 ([0043]), and the breakdown voltage of the structure is determined by the doping levels of the semiconductor layer 4 and the sidewall implant 34 ([0053]). Accordingly, a person of ordinary skill in the art before the effective filing date of the claimed invention would be motivated to include a first deep well between the first well and the second surface and having a doping concentration lower than that of the first contact region in the photodetection element of Teva in view of Webster, as taught by Keshavarzian, to be able to precisely determine the location of the space-charge region and avalanche region in the photodetection element all around the first well.
Regarding claim 8, Teva in views of Webster and Keshavarzian teaches the photodetection element of claim 7, wherein,
the combination of Teva, Webster, and Keshavarzian also teaches that in the first node region (comprising layers in trench 3 of Teva including the first deep well introduced by Keshavarzian (see claim 7 rejection above), Teva’s Fig. 3) extending along a second direction (vertical direction, Fig. 3) intersecting the first direction (horizontal direction in Fig. 3), a central portion of the first contact region (contact region 5, Fig. 3) and a central portion of the first deep well (DPW region of Keshavarzian (Fig. 1(b)) introduced in Fig. 3 of Teva, surrounding the semiconductor layer 4 (corresponds to PW region of Keshavarzian)) are arranged to overlap.
Regarding claim 9, Teva in views of Webster and Keshavarzian teaches the photodetection element of claim 7, wherein,
Teva in views of Webster and Keshavarzian in the first node region (comprising layers in trench 3 of Teva including the first deep well introduced by Keshavarzian (see claim 7 rejection above), Teva’s Fig. 3) extending along a second direction (vertical direction, Fig. 3) intersecting the first direction (horizontal direction, Fig. 3), the first deep well (DPW region of Keshavarzian (Fig. 1(b)) introduced in Fig. 3 of Teva, surrounding the semiconductor layer 4 (corresponds to PW region of Keshavarzian)) surrounds the first contact region (contact region 5, Fig. 3) and extends along the second direction (vertical direction, Fig. 3).
Claims 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over by Teva (US 2016/0035929 A1) in view of Webster (US 2013/0193546 A1) as applied to claims 4-6 above, and further in views of Ha (Ha et al., "Noise optimization of single-photon avalanche diodes fabricated in 110 nm CMOS image sensor technology," Opt. Express 30, 14958-14965 (2022)) and Gramuglia (US 2024/0347664 A1).
Regarding claim 10, Teva in view of Webster teaches the photodetection element of claim 4, wherein
Teva further teaches that the second node region (comprising contact well 6, Fig. 3) includes:
a second contact region (contact well 6, Fig. 3).
Teva and Webster, however, do not teach that
a second well provided between the second contact region and the second surface and having a doping concentration lower than that of the second contact region.
Ha, on the other hand, teaches a photodetection element (single-photon avalanche diode, Fig. 1(d)), wherein the second node region (comprising N+ region, NW region, and DNW region) includes:
a second well (NW region, Fig. 1(d)) provided between the second contact region (N+ region, Fig. 1(d)) and the second surface (bottom surface, Fig. 1(d)) and having a doping concentration lower than that of the second contact region (N+ region, Fig. 1(d): N+ vs N).
Ha further discloses that the structures around the first and second node interact with the first and second node structures to determine the electric fields between the first node and second node (Fig. 4). Furthermore, Gramuglia teaches that making the first node and second node the same depth, the electric fields between the first node and second node can be made uniform (Figs. 1A-B, [0019]) which would make the responses at different depths similar ([0019]) and a deep cathode (second node) provides a low-resistivity path for the cathode (second node) ([0022]). Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention would be motivated to include a second well between the second contact region and the second surface in the photodetection element of Teva in view of Webster, as taught by Ha, to further adjust the electric fields between the first node and second node to obtain a uniform distribution of electric fields which would lower the resistance between the first and second nodes. Furthermore, a person of ordinary skill in the art before the effective filing date of the claimed invention would also keep the second contact region at a high doping level to facilitate a low resistance contact to the second node.
Regarding claim 11, while Teva in view of Webster and Ha teaches the photodetection element of claim 10,
Teva and Webster do not teach that the second node region further includes a second deep well provided between the second well and the second surface and having a doping concentration lower than that of the second contact region.
Ha, on the other hand, teaches a photodetection element (single-photon avalanche diode, Fig. 1(d)), wherein the second node region (comprising N+ region, NW region, and DNW region, Fig. 1(d)) further includes a second deep well (DNW region, Fig. 1(d)) provided between the second well (NW region) and the second surface (bottom surface of the P-epi layer, Gig. 1(d)) and having a doping concentration lower than that of the second contact region (N+ region, Fig. 1(d); N+ vs N).
Ha further discloses including deep well region in the first and second nodes generates another avalanche multiplication region deeper in the device, and the deep avalanche multiplication region improves the photon detection probability at near infrared regime (page 2, last paragraph). Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention would be motivated to include a second deep well at the bottom of the first node region and the second node region in the photodetection element of Teva in view of Ha, as disclosed by Ha, to obtain an additional avalanche multiplication region, which would improve the photon detection at near infrared wavelengths.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over by Teva (US 2016/0035929 A1) as applied to claims 1-3, 15, and 18 above, and further in view of Ha (Ha et al., "Noise optimization of single-photon avalanche diodes fabricated in 110 nm CMOS image sensor technology," Opt. Express 30, 14958-14965 (2022)).
Regarding claim 12, while Teva teaches the photodetection element of claim 1,
Teva does not teach that the photodetection element further comprises:
a buried well provided between the first node region and the second surface and between the second node region and the second surface, extending along the first direction, and having the second conductivity type; and
an additional avalanche multiplication region formed between the first node region and the buried well.
Ha, on the other hand, teaches a photodetection element (single-photon avalanche diode, Fig. 1(d)) comprising:
a buried well (deep n-well (DNW) DNW, Figs. 1(d) and 2(b)) provided between the first node region (comprising P+ region and PW region, Figs. 1(d) and 2(b)) and the second surface (bottom surfaces of the devices in Figs. 1(d) and 2(b)) and between the second node region (comprising N+ region and NW region, Figs. 1(d) and 2(b)) and the second surface (bottom surfaces of the devices in Figs. 1(d) and 2(b)), extending along the first direction (horizontal directions in Figs. 1(d) and 2(b)), and having the second conductivity type (opposite of the first node which has first conductivity type); and
an additional avalanche multiplication region (high electric field region shown in the right panel of Fig. 4) formed between the first node region (comprising P+ region and PW region, Figs. 1(d) and 2(b)) and the buried well (DNW, right panel of Fig. 4).
Ha further discloses that deep avalanche multiplication region improves the photon detection probability at near infrared regime (page 2, last paragraph). Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention would be motivated to include a buried well between the first node region and the second surface and between the second node region and the second surface, extending along the first direction, in the photodetection element of Teva, as disclosed by Ha, to obtain an additional avalanche multiplication region formed between the first node region and the buried well, which would improve the photon detection at near infrared wavelengths.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over by Teva (US 2016/0035929 A1) in view of Ha (Ha et al., "Noise optimization of single-photon avalanche diodes fabricated in 110 nm CMOS image sensor technology," Opt. Express 30, 14958-14965 (2022)) as applied to claim 12 above, and further in view of Gramuglia (US 2024/0347664 A1).
Regarding claim 13, while Teva in view of Ha teaches the photodetection element of claim 12,
Teva does not teach that the second node region and the buried well are in contact with each other.
Ha, on the other hand, teaches a photodetection element (single-photon avalanche diode, Fig. 1(d)), wherein the second node region (comprising N+ region and NW region, Fig. 1(d)) is extended in the second direction (vertical direction in Fig. 1(d)) such that the second node region (comprising N+ region and NW region, Fig. 1(d)) and the buried well (deep n-well (DNW) DNW, Figs. 1(d)) are in contact with each other.
Ha further discloses that the structures around the first and second node interact with the first node (P+ region and PW region, Fig. 1(d)) and second node (comprising N+ region and NW region, Fig. 1(d)) to determine the electric fields between the first node and second node (Fig. 4). Furthermore, Gramuglia teaches that making the first node and second node the same depth, the electric fields between the first node and second node can be made uniform (Figs. 1A-B, [0019]) which would make the responses at different depths similar ([0019]) and a deep cathode (second node) provides a low-resistivity path for the cathode (second node) ([0022]). Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention would be motivated to extend the second node in the photodetection element of Teva in view of Ha along the second direction until the second node contacts the buried well, as taught by Ha, to further adjust the electric fields between the first node and second node to obtain a uniform distribution of electric fields which would lower the resistance between the first and second nodes.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over by Teva (US 2016/0035929 A1) as applied to claims 1-3, 15, and 18 above, and further in view Rae (US 2019/0097075 A1).
Regarding claim 14, while Teva teaches the photodetection element of claim 1,
Teva does not teach that the photodetection element further comprises:
a buried insulating layer provided between the first node region and the second surface and between the second node region and the second surface, extending along the first direction, and including an electrical insulating material.
Rae, on the other hand, teaches a photodetection element (single photon avalanche diode (SPAD) 300, Fig. 3, [0013]) comprising:
a buried insulating layer (buried oxide (BOX) layer 306, Fig. 3, [0013]) provided between the first node region (comprising deep well 330 and heavily doped electrode 336, Fig. 3, [0015]) and the second surface (bottom surface of the substrate 302, Fig. 3, [0013]) and between the second node region (heavily doped electrode 346, Fig. 3, [0015]) and the second surface (bottom surface of the substrate 302, Fig. 3, [0013]), extending along the first direction (horizontal direction, Fig. 3), and including an electrical insulating material ([0014]: buried oxide (BOX) layer 306 electrically isolates different regions).
Rae further discloses that “deep trench isolation structures 318 delimit a SPAD region 320 of the layers 308 and 312 which support the SPAD 300 and, with the assistance of the BOX layer 306, electrically insulate (isolate) that region 320 from other regions 322 of the layers 308 and 312”. Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention who is aiming to include other electronic devices on the substrate where the photodetection element of Teva, would be motivated to include a buried oxide layer and deep trench isolation structures around the single-photon avalanche detection region to be able to electrically isolate different devices from each other.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over by Teva (US 2016/0035929 A1) as applied to claims 1-3, 15, and 18 above, and further in view Yorikado (US 2018/0211990 A1).
Regarding claim 16, while Teva teaches the photodetection element of claim 15,
Teva does not teach that the optical element layer includes a plurality of lenses,
optical axes of the plurality of lenses are located within the avalanche multiplication region.
Yorikado, on the other hand, teaches a photodetection element (single-photon avalanche diode (SPAD) 112 in pixel 110, Fig. 3, [0046]-[0048]), wherein the optical element layer (layer with microlenses 121, Fig. 3, [0047]) includes a plurality of lenses (microlenses 121, Fig. 3),
optical axes (center of lenses) of the plurality of lenses (microlenses 121, Fig. 3) are located within the avalanche multiplication region (SPAS 112, Fig. 3).
Yorikado further discloses that microlenses form the light collecting section of the photodetection element ([0009]) and the light collecting section causes light from a subject to be collected in the light receiving surface other than a region where the electrode is placed (Abstract, see also Fig. 3). Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention would be motivated to include a plurality of microlenses in the optical element layer of Teva with optical axes located within the avalanche multiplication region (light receiving surface), as taught by Yorikado, so that the incident light is effectively delivered to the avalanche multiplication region for optimal amplification.
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over by Teva (US 2016/0035929 A1) as applied to claims 1-3, 15, and 18 above, and further in view Uenoyama (US 2023/0358606 A1).
Regarding claim 17, while Teva teaches the photodetection element of claim 15,
Teva does not teach that the optical element layer includes a plurality of optical patterns,
wherein the plurality of the optical patterns diffract or scatter incident light and transmit the incident light to the avalanche multiplication region.
Uenoyama, on the other hand teaches a photodetection element (light detector 1, Figs. 1 and 7, [0040]), wherein the optical element layer (lens layer 3, Figs. 1 and 7, [0040]) includes a plurality of optical patterns (meta-lens 30 comprising unit structures 31, Figs. 7 and 10),
wherein the plurality of the optical patterns (meta-lens 30 comprising unit structures 31, Figs. 7 and 10) diffract or scatter incident light and transmit the incident light ([0008]: “According to the light detector, it is possible to simultaneously generate diffraction by a meta-lens (a plurality of unit structures) and diffraction by an opening region (opening diffraction). By simultaneously generating two types of diffraction in this manner, it is possible to form a light-condensing point at a position closer to the light incident surface than a focus point in a case where only diffraction by the meta-lens occurs (that is, a focus point set by a plurality of unit structures constituting the meta-lens).”) to the avalanche multiplication region (light receiving region LA of the APD, Fig. 7, [0041]).
Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention would be motivated to include a plurality of optical patterns in the optical element layer of Teva, as taught by Uenoyama, to be able to direct the light to the collecting section (avalanche multiplication region) of the photodetection element, while keeping the device thickness because of shallow focal depth generated by a thinner optical layer of Uenoyama.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over by Teva (US 2016/0035929 A1) as applied to claims 1-3, 15, and 18 above, and further in view Webster (US 2013/0193546 A1).
Regarding claim 19, Teva teaches the photodetection element of claim 15, wherein the connection layer (embedded metal layers 10 within the dielectric 9, Fig. 3, [0041]) is provided on the first surface (top surface of the epitaxial layer 2, Fig. 3).
Teva, however, does not teach that
the optical element layer is provided on the second surface.
Webster, on the other hand teaches a photodetection element (back-side illumination (BSI) variant of single-photon avalanche diode (SPAD), Fig. 25, [0180]), wherein the connection layer (the layer containing anode and cathode, Fig. 25) is provided on the first surface (the bottom surface in Fig. 25),
wherein the optical element layer (antireflection coating, Fig. 25) is provided on the second surface (top surface (corresponding to bottom surface of the substrate) in Fig. 25).
Webster further discloses that “Back Side Illumination is a feature that can be used with CMOS image sensors and CCDs to enhance the light sensitivity of scientific imagers and micron-pitch commercial CMOS image sensors. The major advantage of back-side illumination in these applications is improved fill factor and light sensitivity. Back-side illumination can improve the fill factor and blue spectral response of the present device”. Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention would be motivated to modify the photodetection element of Teva so that that the optical element layer is provided on the second surface, which would provide the benefit of improving the fill factor and blue spectral response of the device in specific applications.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over by Bohli (US 2023/0266446 A1) in view of Teva (US 2016/0035929 A1).
Regarding claim 20, Bohli teaches an electronic device (optoelectronic sensor 10, Fig. 1, [0024]) comprising a light emitting device (light source 16, Fig. 1, [0024]) and a photodetection element (light receiver 36, Fig. 1, [0026]: “light receiver 36 is preferably … SPAD (Single-Photon Avalanche Diode), ...”) that detects incident light (light pulse 28, Fig. 1, [0025]) reflected from a subject (object 24, Fig. 1, [0025]: “The at least one light pulse 28 reflected or remitted at an object 24 in the monitoring area 26 is guided as a received light beam 30 via an (optional) optical filter 32 for suppressing interfering light and a receiving optical system 34 to a light receiver 36”) and returned after being emitted (Fig. 1: one light pulse 20, [0024]) from the light emitting device (light source 16, Fig. 1) , and configured (via the object distance estimation unit 54, Fig. 1, [0028]) to measure a distance to the subject using time difference information between a transmission signal of the light emitting device and a detection signal of the photodetection element ([0028]:” The light travel time is transmitted to the object distance estimation unit 54, which determines a distance of the object 24 to the sensor based on the time-of-flight of the light”).
Bohli, however, is silent on the structure of the photodetection element, and therefore does not teach that the photodetection element includes:
a substrate having a first surface and a second surface provided on opposite sides of each other, a first node region provided within the substrate and having a first conductivity type, a second node region spaced apart from the first node region within the substrate and having a second conductivity type different from the first conductivity type, and an avalanche multiplication region formed between the first node region and the second node region,
wherein the first node region, the avalanche multiplication region, and the second node region are arranged along a first direction parallel to the first surface.
Teva, on the other hand, teaches a photodetection element (lateral single-photon avalanche diode, Figs. 3-4, [0043]-[0044]), wherein the photodetection element includes:
a substrate (comprising substrate 1 and epitaxial layer 2, Fig. 3, [0037]) having a first surface (top surface of the epitaxial layer 2, Fig. 3) and a second surface (bottom surface of the substrate 1, Fig. 3 (the bottom surface is not shown in Fig. 3)) provided on opposite sides of each other, a first node region (comprising layers in trench 3, Fig. 3, [0038]) provided within the substrate (comprising substrate 1 and epitaxial layer 2, Fig. 3) and having a first conductivity type (corresponds to second type of electrical conductivity in Teva; [0043]: “the trench 3 is completely filled with doped polysilicon of the second type of electric conductivity.”), a second node region (comprising contact well 6, Fig. 3, [0040]) spaced apart from the first node region (comprising layers in trench 3, Fig. 3) within the substrate (comprising substrate 1 and epitaxial layer 2, Fig. 3) and having a second conductivity type (corresponds to first type of electrical conductivity in Teva [0054]: “first type of electric conductivity”) different from the first conductivity type (second type of electrical conductivity in Teva), and an avalanche multiplication region (junction region 14, Fig. 3, [0039]: ”During an operation of the single-photon avalanche diode the junction region 14 is a region of high electric field strength.”, and therefore junction region 14 is the avalanche multiplication region) formed between the first node region (comprising layers in trench 3, Fig. 3) and the second node region (comprising contact well 6, Fig. 3),
wherein the first node region (comprising layers in trench 3, Fig. 3), the avalanche multiplication region (junction region 14, Fig. 3), and the second node region (comprising contact well 6, Fig. 3) are arranged along a first direction (horizontal direction. Fig. 3) parallel to the first surface (top surface of the epitaxial layer 2, Fig. 3).
Teva, further discloses that the lateral single-photon avalanche diode of Teva has several advantages: the absorption of infrared wavelengths is increased without increasing the breakdown voltage of the diode, and the electric field is constant at the central region of the trench, ensuring that the avalanche is triggered independently of the depth where the electron-hole pair is generated. Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention would be motivated to use the photodetection element of Teva in the electronic device of Bohli to obtain a device with increased absorption in the infrared wavelength, which are commonly used in time-of-flight measurement devices such as the electronic device of Bohli.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Lim (US 2022/0115552 A1) teaches a single-photon avalanche diode (SPAD), which is relevant to all claims.
Natsuaki (US 2019/0280145 A1) teaches a single-photon avalanche diode (SPAD), which is relevant to all claims.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ILKER OZDEN whose telephone number is (703)756-5775. The examiner can normally be reached Monday - Friday 8:30am-5:30pm.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, William B Partridge can be reached at 571-270-1402. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/ILKER NMN OZDEN/Examiner, Art Unit 2812
/William B Partridge/Supervisory Patent Examiner, Art Unit 2812
Prosecution Insights