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 .
Response to Arguments
The applicant asserts on page 13 that “The ratio in Liu is therefore exactly 1:1 and cannot be otherwise. The reason this is structural rather than merely a matter of which embodiment Liu happened to illustrate is that, in Liu, the elevated region is not a body added to the grid - it is the grid. Liu says so expressly in para. [0043]: ‘the upper surfaces of the intersection points 302 are upper surfaces of the metal grid layer 112, respectively.’ The elevation arises from Liu's two-layer patterning sequence, in which a first metal layer is etched according to a masking layer together with previously defined elongated metal segments, so that additional metal height persists wherever the two segment sets cross. Further detailed in para. [0020] of Liu: ‘A second masking layer is formed over the plurality of elongated metal segments, such that the second masking layer comprises a plurality of elongated masking segments arranged in parallel with one another and extending in a second direction orthogonal to the first direction. A second etching process is then performed on the first metal layer according to the masking layer and the plurality of elongated metal segments, thereby defining a metal grid structure.’ Every crossing of the two segment sets produces the same result. Liu’s process cannot yield a grid in which some intersections are elevated and others are not, and Liu neither discloses nor suggests any reason to seek such a structure.”
The applicant’s assertion here is that because Liu discloses using a process that produces raised portions at the intersections, it must do so, and cannot be altered to do otherwise. This is manifestly not true. All that would need to be done would be to change the deposition patterns of the masks that define the etching processes. There is nothing that would prevent it, or even make it difficult.
The applicant asserts on page 14 that “The Examiner concedes on page 14 of the 05/05/26 Office Action that ‘Liu does not disclose the electrical state of the grid" and relies on Wen, asserting that Wen ‘discloses a grid 116/324 that improves quantum efficiency ([0027]) and that is connected to ground (FIG. 3, ground region 332 'configured to enable the discharge of built-up charges' [0042]),’ such that ‘[i]t would have been obvious to have had such a ground connection to prevent charges from building up in a conductive grid.’ Wen does not disclose a grounded grid. Wen's ground structure is a separate element, laterally removed from the pixel array and extending downward into the substrate. Referring to [0042] of Wen: "A ground region 332 is disposed at a location laterally offset from the pixel regions, 103a-103b. The ground region 332 comprises a ground structure 330 comprising a conductive layer extending through the absorption enhancement structure 212 to the substrate 102." Referring to para. [0056], Wen forms the two as distinct structures - "the conductive material (1102 of FIG. 11) is selectively etched to form a grid structure 324 and a ground structure 330 within a ground region 332." - and what Wen grounds is the substrate, not the grid.”
See Wen [0042]: “During fabrication of the CIS integrated chip 300, ions (e.g., from a dry etching process) striking the grid structure 324 may generate charges, which build up within the substrate 102. The ground region 332 is configured to enable the discharge of built-up charges, thereby improving performance of the CIS integrated chip 300.” The ground region is to discharge charges built up in the grid. The grid is connected to the ground region; see FIGS. 12 and 13.
The applicant asserts that “Wen’s charges do not accumulate in the grid, and do not arise in operation; they accumulate in the substrate during manufacture, with the grid acting as the object struck. Referring to para. [0042] of Wen: ‘During fabrication of the CIS integrated chip 300, ions (e.g., from a dry etching process) striking the grid structure 324 may generate charges, which build up within the substrate 102. The ground region 332 is configured to enable the discharge of built-up charges, thereby improving performance of the CIS integrated chip 300.’ A rationale of preventing charge build-up ‘in a conductive grid" is therefore not drawn from Wen.’” The rejection did not specify that the charges would be accumulated during operation, so this rejection is inapropos.
The applicant asserts on page 17 that “On page 12 of the 05.05.26 Office Action, the Examiner reasoned that ‘In Liu in view of Chen, the metal projections would extend through the passivation layer, as they are higher than the rest of the grid.’ Chen does not support that reasoning: its passivation layer covers only part of the grid's flank and does not encompass the grid at all. Referring of para. [0054] of Chen, ‘A passivation layer 27 may be further formed over the insulating layer 26. The passivation layer 27 may be a dielectric material including silicon-dioxide, nitride, oxynitride. The passivation layer 27 covering a portion of the lateral side of the metal grid pattern 28.’ Since Chen discloses no projections whatsoever, the conclusion that projections ‘would extend through the passivation layer" is drawn from Applicant's disclosure rather than from the references.”
The applicant’s assertion that the “passivation layer covers only part of the grid's flank and does not encompass the grid” is not relevant, as the claim language does not require the passivation layer to encompass the grid. The projections extend through the passivation layer regardless. It is true that Chen does not disclose projections; this is a 103 rejection – the projections come from Liu. Passivation layers were very common, especially over conductive structures, and it would not have been surprising at all for a passivation layer to be present in Liu.
The applicant argues on page 18 that “The fact that a certain result or characteristic may occur or be present in the prior art is not sufficient to establish the inherency of that result or characteristic. Referring to MPEP 2112, the burden lies with the Examiner to articulate why the feature must be present: "In relying upon the theory of inherency, the examiner must provide a basis in fact and/or technical reasoning to reasonably support the determination that the allegedly inherent characteristic necessarily flows from the teachings of the applied prior art." Where inherency is invoked to supply a missing limitation within an obviousness combination, the standard is stricter still: "the use of inherency, a doctrine originally rooted in anticipation, must be carefully circumscribed in the context of obviousness," and "in order to rely on inherency to establish the existence of a claim limitation in the prior art in an obviousness analysis - the limitation at issue necessarily must be present, or the natural result of the combination of elements explicitly disclosed by the prior art.’”
All of the present rejections are under 35 USC 103. As set forth in In re Best, “Where, as here, the claimed and prior art products are identical or substantially identical, or are produced by identical or substantially identical processes, the PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of his claimed product. See In re Ludtke, supra. Whether the rejection is based on ‘inherency’ under 35 USC 102, on ‘prima facie obviousness’ under 35 USC 103, jointly or alternatively, the burden of proof is the same, and its fairness is evidenced by the PTO's inability to manufacture products or to obtain and compare prior art products.” In re Best, 562 F.2d 1252, 1254, 195 USPQ 430, 433-434 (CCPA 1977). These rejections do not need to rely on inherency. They can rely on the obviousness that the stated features will be present due to the similar structure.
More generally with respect to the applicant’s arguments regarding In re Best, the combination of references is very similar to the claimed structure, and would be expected to have the same function.
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the ratio of the set of metal projections to the intersections of the metal grid is less than 1:1 must be shown or the feature(s) canceled from the claim(s). No new matter should be entered.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Interpretation
Claims 5, 12, and 20 recite “is comprised in” or “are comprised in”, which the examiner understands to mean “makes up part of”.
The terms “rectangle based cone” and triangle based cone” are understood to refer to a shape with side surfaces connecting a rectangle or triangle at the bottom and a point at the top (or vice versa).
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 1, 2, 3, 5, 6, 15, 17, 19, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Liu, US 2022/0285412 A1, in view of Wen, US 2018/0151615 A1, and Chen, US 2019/0371845 A1.
Claim 1: Liu discloses
an array of photodiodes (102);
a metal grid (114) coupled to the array of photodiodes;
and a set of metal projections (302) extending away from the metal grid.
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Liu does not disclose the electrical state of the grid. However, Liu discloses that “The metal grid structure is configured to increase sensitivity (e.g., quantum efficiency (QE)) and reduce cross-talk between adjacent photodetectors.” [0018]. Wen discloses a grid 116/324 that improves quantum efficiency ([0027]) and that is connected to ground (FIG. 3, ground region 332 “configured to enable the discharge of built-up charges” in the grid [0042]). It would have been obvious to have had such a ground connection to prevent charges from building up in a conductive grid that could interfere with the functioning of the device, during manufacturing or otherwise.
Claim 1 also recites that the set of metal projections is configured to direct charge from one of electrostatic discharge or static charge into the metal grid. This is a function or intended use of the device. As the structure is the same in relevant respects, including the grounding of the grid, the same functioning will attain, or the structure would suggest to those in the art the same functionality. “Where, as here, the claimed and prior art products are identical or substantially identical, or are produced by identical or substantially identical processes, the PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of his claimed product. See In re Ludtke, supra. Whether the rejection is based on ‘inherency’ under 35 USC 102, on ‘prima facie obviousness’ under 35 USC 103, jointly or alternatively, the burden of proof is the same, and its fairness is evidenced by the PTO's inability to manufacture products or to obtain and compare prior art products.” In re Best, 562 F.2d 1252, 1254, 195 USPQ 430, 433-434 (CCPA 1977). Thus this feature can be considered as either inherent under 35 USC 102 or prima facie obviousness under 35 USC 103.
Liu does not specifically disclose that the set of metal projections extend through a layer of passivation material coupled to the metal grid. However, this was known in the art. See Chen, FIG. 2, metal grid 28 extending through a passivation layer 27. It would have been obvious to have such a passivation layer in Liu in order to passivate the metal grid, that is, to prevent undesired interactions (electrical, chemical, etc.) with the environment. In Liu in view of Chen, the metal projections would extend through the passivation layer, as they are higher than the rest of the grid.
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Claim 2: the set of metal projections are located on a side (the top, FIG. 4) of the metal grid opposite the array of photodiodes.
Claim 3: the set of metal projections are each located at a set of intersections of the metal grid (FIG. 4).
Claim 5: the array of photodiodes is comprised in a backside illumination sensor. “A process for forming the metal grid structure includes depositing a first metal layer over a surface of a substrate (e.g., a back-side surface of the semiconductor substrate) and depositing a second metal layer over the first metal layer.” [0020]. As the photodetectors 102 are closer the back side (104b, top side in the figures), those in the art would recognize the illustrated device as a backside illumination sensor.
Claim 6 recites that the set of metal projections comprise one of a cylinder or a triangular prism. The specification does not disclose a reason why one would choose one shape rather than another. Changes in shape are not typically a source of patentable distinction absent unexpected results. MPEP 2144.04(IV).
Claim 15: Liu discloses
providing an array of photodiodes (12) with a first side to which a metal grid (114) is coupled and a set of metal projections (302) coupled to the metal grid on a side of the metal grid opposite the first side of the array of photodiodes and extending away from the metal grid;
Liu does not disclose the electrical state of the grid. However, Liu discloses that “The metal grid structure is configured to increase sensitivity (e.g., quantum efficiency (QE)) and reduce cross-talk between adjacent photodetectors.” [0018]. Wen discloses a grid 116/324 that improves quantum efficiency ([0027]) and that is connected to ground (FIG. 3, ground region 332 “configured to enable the discharge of built-up charges” [0042]). It would have been obvious to have had such a ground connection to prevent charges from building up in a conductive grid.
Liu does not disclose the electrical state of the grid. However, Liu discloses that “The metal grid structure is configured to increase sensitivity (e.g., quantum efficiency (QE)) and reduce cross-talk between adjacent photodetectors.” [0018]. Wen discloses a grid 116/324 that improves quantum efficiency ([0027]) and that is connected to ground (FIG. 3, ground region 332 “configured to enable the discharge of built-up charges” in the grid [0042]). It would have been obvious to have had such a ground connection to prevent charges from building up in a conductive grid that could interfere with the functioning of the device, during manufacturing or otherwise.
Claim 15 also recites receiving electric charge into the set of metal projections; and directing the electric charge into the metal grid. As the structure is the same in relevant respects, the same functioning will attain. “Where, as here, the claimed and prior art products are identical or substantially identical, or are produced by identical or substantially identical processes, the PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of his claimed product. See In re Ludtke, supra. Whether the rejection is based on ‘inherency’ under 35 USC 102, on ‘prima facie obviousness’ under 35 USC 103, jointly or alternatively, the burden of proof is the same, and its fairness is evidenced by the PTO's inability to manufacture products or to obtain and compare prior art products.” In re Best, 562 F.2d 1252, 1254, 195 USPQ 430, 433-434 (CCPA 1977).
Claim 15 also recites that the set of metal projections extend through a passivation layer. Liu perhaps does not specifically disclose this. However, this was known in the art. See Chen, FIG. 2, metal grid 28 extending through a passivation layer 27. It would have been obvious to have such a passivation layer in Liu in order to passivate the metal grid, that is, to prevent undesired interactions (electrical, chemical, etc.) with the environment. In Liu in view of Chen, the metal projections would extend through the passivation layer, as they are higher than the rest of the grid.
Claim 15 also recites that the set of metal projections comprise one of a cone, a cylinder or a triangular prism. The specification does not disclose a reason why one would choose one shape rather than another. Changes in shape are not typically a source of patentable distinction absent unexpected results. MPEP 2144.04(IV).
Claim 17: Liu and the present invention both have the claimed grid surrounded by insulating material. Thus, they will both similarly receive electric charge from a passivation layer. “Where, as here, the claimed and prior art products are identical or substantially identical, or are produced by identical or substantially identical processes, the PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of his claimed product. See In re Ludtke, supra. Whether the rejection is based on ‘inherency’ under 35 USC 102, on ‘prima facie obviousness’ under 35 USC 103, jointly or alternatively, the burden of proof is the same, and its fairness is evidenced by the PTO's inability to manufacture products or to obtain and compare prior art products.” In re Best, 562 F.2d 1252, 1254, 195 USPQ 430, 433-434 (CCPA 1977).
Claim 19: Liu and the present invention both have the claimed grid surrounded by insulating material. Thus, they will both similarly receive electrostatic discharge events or static electricity. “Where, as here, the claimed and prior art products are identical or substantially identical, or are produced by identical or substantially identical processes, the PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of his claimed product. See In re Ludtke, supra. Whether the rejection is based on ‘inherency’ under 35 USC 102, on ‘prima facie obviousness’ under 35 USC 103, jointly or alternatively, the burden of proof is the same, and its fairness is evidenced by the PTO's inability to manufacture products or to obtain and compare prior art products.” In re Best, 562 F.2d 1252, 1254, 195 USPQ 430, 433-434 (CCPA 1977).
Claim 20: the array of photodiodes is comprised in a backside illumination sensor. “A process for forming the metal grid structure includes depositing a first metal layer over a surface of a substrate (e.g., a back-side surface of the semiconductor substrate) and depositing a second metal layer over the first metal layer.” [0020]. As the photodetectors 102 are closer the back side (104b, top side in the figures), those in the art would recognize the illustrated device as a backside illumination sensor.
Claims 8-10, 12, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Liu in view of Wen.
Claim 8: Liu discloses
an array of photodiodes (102);
a metal grid coupled (114) on a first side of the array of photodiodes;
and a set of metal projections (3o2, FIG. 4) coupled on a side (top) of the metal grid opposite the first side of the array of photodiodes and extending away from the metal grid.
wherein the set of metal projections are each located at a set of intersections of the metal grid (Liu FIG. 4).
Liu does not disclose that a ratio of the set of metal projections to the intersections of the metal grid is less than 1:1. This would encompass intersection not having a projection. With a typical imaging sensor with millions of pixels, all that this would require is that a single intersection have an etching error producing something other than a projection. This would have been a quite probable outcome of the manufacturing process, and such a one-off error would not be a source of patentable distinction.
Liu does not disclose the electrical state of the grid. However, Liu discloses that “The metal grid structure is configured to increase sensitivity (e.g., quantum efficiency (QE)) and reduce cross-talk between adjacent photodetectors.” [0018]. Wen discloses a grid 116/324 that improves quantum efficiency ([0027]) and that is connected to ground (FIG. 3, ground region 332 “configured to enable the discharge of built-up charges” [0042]). It would have been obvious to have had such a ground connection to prevent charges from building up in a conductive grid.
Claim 9: the set of metal projections are each located at a set of intersections of the metal grid (FIG. 4).
Claim 12: the array of photodiodes are comprised in a backside illumination sensor. “A process for forming the metal grid structure includes depositing a first metal layer over a surface of a substrate (e.g., a back-side surface of the semiconductor substrate) and depositing a second metal layer over the first metal layer.” [0020]. As the photodetectors 102 are closer the back side (104b, top side in the figures), those in the art would recognize the illustrated device as a backside illumination sensor.
Claim 13 recites that the set of metal projections comprise one a cylinder or a triangular prism. The specification does not disclose a reason why one would choose one shape rather than another. Changes in shape are not typically a source of patentable distinction absent unexpected results. MPEP 2144.04(IV).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Liu in view of Wen, Chen, Hsieh, US 2016/0141321 A1, or Wang, 2014/0339615 A1. Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Liu in view of Wen and further in view of Hsieh or Wang. Liu does not disclose that the set of metal projections comprise one of a square based cone, a triangle based cone, a cone, or a conical frustum. However, a shape of a (rectangular based) conical frustrum was known in the art. See Wang FIG. 1A, with grid 112 having a cross section of a conical frustrum,
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and Hsieh, FIG. 4B, with the grid 40 having an upper portion having the cross section with a (rectangular based) conical frustrum.
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It would have been obvious to have had this shape from etching, as most or all etching processes do not produce vertical sidewalls, but sidewalls with some slant. Note that the projections 302 of Liu, having four slanted sides, with have the three-dimensional shape of a (rectangular based) conical frustrum.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Liu in view of Wen and Chen. Liu does not specifically disclose that the set of metal projections are in a layer of passivation material coupled to the side of the metal grid opposite the first side of the array of photodiodes. However, this was known in the art. See Chen, FIG. 2, metal grid 28 extending through a passivation layer 27. It would have been obvious to have such a passivation layer in Liu in order to passivate the metal grid, that is, to prevent undesired interactions (electrical, chemical, etc.) with the environment. In Liu in view of Chen, the metal projections would extend through the passivation layer, as they are higher than the rest of the grid.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to PETER BRADFORD whose telephone number is (571)270-1596. The examiner can normally be reached 10:30-6:30.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jacob Choi can be reached at 469.295.9060. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/PETER BRADFORD/Primary Examiner, Art Unit 2897
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