DETAILED ACTION
Election/Restrictions
Applicant’s election without traverse of claims 8-14 & 21-33 in the reply filed on 09/29/25 is acknowledged.
Election was made without traverse in the reply filed on 09/29/25.
Allowable Subject Matter
Claim 33 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.
In simplest terms, the content of claim 33 requires DTI trenches to have 3 different depths. Together with other claims, on which claim 33 depends (claims 29, 30 and 31), this requires a very specific combined structure (see Applicant’s FIG. 15C, for example), which prior art does not teach. Hence, indication of allowable subject matter.
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 of this title, 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 8-11 are rejected under 35 U.S.C. 103 as being unpatentable over (US-2019/0067355) by Li et al (“Li”).
Regarding claim 8, Li discloses in FIGs. 1-5 and related text, e.g., a method, comprising:
forming a plurality of photodiodes (FIG. 5, 506) in a substrate (502) of a pixel sensor array (FIG. 5);
performing a plurality of etch-deposition-etch cycles to form a plurality of trenches (FIG. 4C, 413) around the plurality of photodiodes in the substrate (see FIG. 5), wherein the plurality of trenches are formed from a top surface of the substrate (the trenches are formed from the same surface, as Applicant; marked as 502b here);
filling the plurality of trenches with one or more dielectric layers (such an embodiment is taught in FIG. 1; 124 are “one or more dielectric materials” (par. 19)) to form a deep trench isolation (DTI) structure (see FIG. 5) that surrounds the plurality of photodiodes (see FIG. 5), wherein two or more DTI portions of the DTI structure extend, from the top surface of the substrate, to different depths in the substrate (the trench 413 has two portions: first of all, there is a top widening portion, that goes to one depth; then, there is another narrowing portion that goes deep into substrate);
forming a grid structure (520) above the substrate and over the DTI structure;
forming a color filter region (522a-c) in between the grid structure and above the plurality of photodiodes; and
forming a micro lens (524) over the color filter region.
Li does not explicitly state “performing a plurality of etch-deposition-etch cycles to form a plurality of trenches”.
Examiner would argue that Li does inherently teach the above teachings, but just not stating them explicitly; detailed information below.
It would have been obvious to one of ordinary skill in the art at the time of the invention to modify the method of making of Li with “performing a plurality of etch-deposition-etch cycles to form a plurality of trenches”, in order to simplify the processing steps of making the device by making the trench in a notoriously well-known way, by using notoriously well-known methods.
First of all, as far as limitations of “plurality of etch-deposition-etch”, see US-5,618,751 by Golden et al, dated 1997 (included as reference material of how one would form a device of Li); Golden makes it clear that at the time of his filing (see col. 2, lines 7-35), the method of forming a trench by use of “plurality of costly etch, deposition and etch back sequences” was already well-known; it is part of his Admitted Prior Art; it is important to note, as is well-known even to general public, semiconductor industry produces a new generation of ever-shrinking chips every 12-18 months (colloquially known as “Moore’s Law”); therefore, a reference dated 1997 is dealing with information that is at least 18 generations old; thus, everything is notoriously well-known and notoriously well-understood.
Second of all, as far as how that results in a shape that both Applicant and Li have (a trench that first gets wider, then narrower), see US-5,871,659 by Sarano et al, dated 1999 (included as reference material of how one would form a device of Li); Sarano uses the same etch-deposit-etch cycle and shows the characteristic shape as a result (see FIG. 6 and related text); please note that Sarano reference is also from the past century, thus also notoriously well-known and notoriously well-understood.
As a conclusion, the reason why the heading above has a single reference (to Li) and not all three references (including Golden and Sarano), is because everything is notoriously well-known and notoriously well-understood; Examiner considers all the material to be reference material as to how one would form a trench of Li (with its characteristic shape) and not separate teaching; in other words, Examiner argues that these teachings (of Golden and Sarano) are simply how one would form trench of Li, and are not separate teachings.
If Applicant disagrees that Li inherently includes the above teachings of Golden and Sarano (as Examiner argues), then consider it a 3 reference rejection, with the same motivation to combine as cited above (“in order to simplify the processing steps of making the device by making the trench in a notoriously well-known way, by using notoriously well-known methods”).
Regarding claim 9, Li discloses in FIGs. 1-5 and related text, e.g., discloses substantially the entirety of claimed subject matter, but does not explicitly state “wherein a bias voltage frequency, that is used in the plurality of etch-deposition-etch cycles, is selected to achieve a particular profile for the DTI structure”.
Examiner would argue that Li does inherently teach the above teachings, but just not stating them explicitly; detailed information below.
It would have been obvious to one of ordinary skill in the art at the time of the invention to further modify the method of making of Li with “wherein a bias voltage frequency, that is used in the plurality of etch-deposition-etch cycles, is selected to achieve a particular profile for the DTI structure”, in order to simplify the processing steps of making the device by making the trench in a notoriously well-known way, by using notoriously well-known methods.
First of all, see US-2002/0144974 by Laermer et al, dated 2002 (included as reference material of how one would form a device of Li). Specifically, in par. 3 (second half of paragraph; especially the last 6 lines), Laermer makes it clear that use of “bias voltage” of specific type of “frequency” was needed to guarantee a desired “wall profile”. Therefore, control of “bias voltage”, specifically its “frequency”, in order to achieve the desired “profile” was Admitted Prior Art by Laermer, back in 2002, which is at least 14 generation old. Hence, this is why Examiner says that this is notoriously well-known and is part of Li’s inherent teachings.
If Applicant disagrees that Li inherently includes the above teachings of Laermer (as Examiner argues), then consider it a 4 reference rejection, with the same motivation to combine as cited above (“in order to simplify the processing steps of making the device by making the trench in a notoriously well-known way, by using notoriously well-known methods”).
Regarding claim 10, Li discloses in FIGs. 1-5 and related text, e.g., wherein performing a first etch-deposition-etch cycle, of the plurality of etch-deposition- etch cycles, comprises:
performing a first etch operation to form the plurality of trenches to a first depth in the substrate (first depth is where Li’s trench gets most wide; compare to Sarano’s FIG. 6, same widening part of trench, and related text on how exactly one makes it);
performing a deposition operation to deposit a sidewall protection layer (Sarano, in FIG. 6, actually calls it by the identical name; see FIG. 6) in the plurality of trenches; and
performing a second etch operation to remove a portion of the sidewall protection layer from bottom surfaces of the plurality of trenches (see the resultant bottom portion of trench in FIG. 6 of Sarano; again, Examiner would argue that all of the above is inherent to Li),
wherein the sidewall protection layer protects sidewalls of the plurality of trenches during a second etch-deposition-etch cycle to increase the depth of the plurality of trenches from the first depth to a second depth (see second half of trench as shown by FIG. 6 of Sarano; one would simply repeat Sarano’s method (as it is further expounded on by Laermer), to make a trench as deep as one needs it).
Regarding claim 11, Li discloses in FIGs. 1-5 and related text, e.g., wherein the first etch operation comprises an isotropic etch operation (as is well-known “isotropic” means that etching process removes matter uniformly in all directions; “isotropic” etching is known to cause undercut; now see FIG. 4C of Li, top part of 413; it is widening [Wingdings font/0xE0] thus forming an undercut [Wingdings font/0xE0] thus the etching process that weas used is an “isotropic” etch operation, by definition; Sarano, in FIG. 6 and related text expounds on all the notoriously well-known technical details); and
wherein the second etch operation comprises an anisotropic etch operation as a result of the sidewall protection layer (as is well-known “anisotropic” means that etching process etches at different rates in different directions [Wingdings font/0xE0] in other words, the etching process is directed; see the bottom portion of 413 of Li, and second portion of trench in FIG. 6 of Sarano; Sarano also explicitly refers to “anisotropy” as key part of the process involved (col. 1, lines 52-57); hence, Examiner would argue, this is all part of inherent teachings of Li, just by looking at the shape of the trench).
Claims 12 & 14 are rejected under 35 U.S.C. 103 as being unpatentable over (US-2019/0067355) by Li et al (“Li”) in view of (US-2021/0118924) by Tamaki et al (“Tamaki”).
Regarding claim 12, Li discloses in FIGs. 1-5 and related text, e.g., wherein performing the plurality of etch-deposition-etch cycles to form the plurality of trenches around the plurality of photodiodes in the substrate comprises:
forming a first trench, of the plurality of trenches, such that the first trench extends to a first shallow trench isolation (STI) region at a bottom surface of the substrate (see FIG. 5, 128; DTI reaches toward 128).
Li does not disclose “forming a second trench, of the plurality of trenches, such that the second trench does not extend to any STI region at the bottom surface of the substrate”.
Tamaki discloses in FIGs. 8-11 and related text, e.g., forming a variety of trenches (312a), of the plurality of trenches, such that the trenches can sometimes extend to STI (FIG. 10, 110, for example) and sometimes do not extend to STI (FIG. 9; 312a and 110 are not aligned).
It would have been obvious to one of ordinary skill in the art at the time of the invention to modify the method of making of Li with “forming a second trench, of the plurality of trenches, such that the second trench does not extend to any STI region at the bottom surface of the substrate” as taught by Tamaki, in order to achieve the desired light alignment (51a/b), and since Tamaki explicitly states that his embodiments can be combined piecemeal (par. 104).
Regarding claim 14, Li discloses in FIGs. 1-5 and related text, e.g., wherein forming the micro lens over the color filter region comprises: forming the micro lens such that the micro lens is at least partially offset relative to the color filter region (first of all, it is vertically offset; second of all, the left and right edges of micro lens are not over color filter at all, and are thus offset from color filter region that way also; thus meeting limitations).
Claims 13 & 21-32 are rejected under 35 U.S.C. 103 as being unpatentable over (US-2019/0067355) by Li et al (“Li”) in view of (US-2021/0118924) by Tamaki et al (“Tamaki”) as applied to claims above, and further in view of (US-11,425,323) by Kim et al (“Kim”).
Regarding claim 13, the combined method of Li and Tamaki disclose in cited figures and related text, e.g., substantially the entire claimed subject matter, but do not disclose “wherein performing the plurality of etch-deposition-etch cycles to form the plurality of trenches around the plurality of photodiodes in the substrate comprises: forming a third trench, of the plurality of trenches, such that the third trench does not extend to any STI region at the bottom surface of the substrate, wherein the third trench extends to a greater depth in the substrate, from the top surface of the substrate, relative to the second trench”.
Kim discloses in FIG. 4B and related text, e.g., “wherein the third trench (right SEP1) extends to a greater depth in the substrate, from the top surface of the substrate, relative to the second trench (central SEP2).
It would have been obvious to one of ordinary skill in the art at the time of the invention to further modify the method of making of Li and Tamaki with “wherein the third trench extends to a greater depth in the substrate, from the top surface of the substrate, relative to the second trench” as taught by Kim, in order to accommodate two photodiodes under a single micro lens (see FIG. 4B).
Regarding claim 21, the combined method of Li, Tamaki and Kim disclose in cited figures and related text, e.g., a method, comprising:
forming a plurality of pixel sensors arranged in a grid, wherein the plurality of pixel sensors correspond to a quadratic photo detection (QPD) region of the pixel sensor array (the arrangement of Kim, in FIG. 4B, with two photodiodes under a single micro lens; thus making the pixel sensor “QPD ready”; Kim has structure that is capable of function; actually using QPD is not a method of making limitation), and wherein a pixel sensor, of the plurality of pixel sensors, comprises:
a first photodiode (PD1 of Kim, FIG. 4B) in a substrate of the pixel sensor array;
a second photodiode (PD2) horizontally adjacent with the first photodiode in the substrate of the pixel sensor array; and
a color filter region (CF) over the first photodiode and the second photodiode;
forming a deep trench isolation (DTI) structure, comprising:
a first DTI portion (left SEP1) that extends from a top surface of the substrate and into the substrate along an outer side of the first photodiode;
a second DTI portion (right SEP1) that extends from the top surface of the substrate and into the substrate along an outer side of the second photodiode; and
a third DTI portion (SEP2) that extends from the top surface of the substrate into the substrate and between the first photodiode and the second photodiode, wherein a depth of the third DTI portion, relative to the top surface of the substrate, is less than a depth of the first DTI portion relative to the top surface of the substrate (see FIG. 4B of Kim), and wherein the depth of the third DTI portion is less than a depth of the second DTI portion relative to the top surface of the substrate (see FIG. 4B).
Regarding claim 22, the combined method of Li, Tamaki and Kim disclose in cited figures and related text, e.g., wherein the depth of the first DTI portion and the depth of the second DTI portion are approximately a same depth (see FIG. 4B).
Regarding claim 23, the combined method of Li, Tamaki and Kim disclose in cited figures and related text, e.g., wherein at least one of the first DTI portion, the second DTI portion, or the third DTI portion comprises:
a flared section; and a tapered section below the flared section (use of “flared” and “tapered” sections was discussed in detail regarding claims 8 & 10-12).
Regarding claim 24, the combined method of Li, Tamaki and Kim disclose in cited figures and related text, e.g., wherein at least one of the first DTI portion, the second DTI portion, or the third DTI portion comprises: a tapered profile that continuously changes in width from the top surface of the substrate toward a bottom surface of the substrate (FIG. 4C of Li, 413).
Regarding claim 25, the combined method of Li, Tamaki and Kim disclose in cited figures and related text, e.g., disclose substantially the entirety of claimed subject matter, but do not explicitly state “wherein at least one of the first DTI portion, the second DTI portion, or the third DTI portion comprises: a plurality of stepped sections that change in width from the top surface of the substrate toward a bottom surface of the substrate”.
It would have been obvious to one of ordinary skill in the art at the time of the invention to further modify the method of making of Li, Tamaki and Kim with “wherein at least one of the first DTI portion, the second DTI portion, or the third DTI portion comprises: a plurality of stepped sections that change in width from the top surface of the substrate toward a bottom surface of the substrate”, since it has been held that change in shape is a matter of choice, which would have been within a scope of POSITA’s abilities (MPEP 2144.04; also, see US-2014/0030840, FIG. 2F, 6a/b, which demonstrate such “stepped section” profile; thus, providing evidence for Examiner’s assertion based on MPEP 2144.04, that such a change in shape would be withing a scope of POSITA’s abilities).
Regarding claim 26, the combined method of Li, Tamaki and Kim disclose in cited figures and related text, e.g., wherein the first DTI portion continuously extends from the top surface of the substrate to a first shallow trench isolation (STI) region at a bottom surface of the substrate (STI’s are shown by Li; just look at STI 128 and corresponding DTI portion);
wherein the second DTI portion continuously extends from the top surface of the substrate to a second STI region at the bottom surface of the substrate (another STI 128 and another corresponding DTI portion); and
wherein the third DTI portion is spaced apart, by the substrate, from a third STI region at the bottom surface of the substrate (yet another STI 128 and this time a DTI that does NOT correspond to it; such combination of elements read on limitations).
Regarding claim 27, the combined method of Li, Tamaki and Kim disclose in cited figures and related text, e.g., wherein the pixel sensor comprises a first pixel sensor of the plurality of pixel sensors (pixel sensor of Kim, FIG. 4B);
wherein the plurality of pixel sensors comprises a second pixel sensor adjacent to the first pixel sensor in the grid; and wherein the second DTI portion extends along an outer side of a third photodiode of the second pixel sensor (FIG. 4B is part of grid of pixels; hence, SEP1 is adjacent to yet another photodiode to the right of it).
Regarding claim 28, the combined method of Li, Tamaki and Kim disclose in cited figures and related text, e.g., a method of forming an image sensor device, comprising:
forming a sensor die, comprising:
a plurality of quadratic photo detection (QPD) regions (see claim 21 for discussion of QPD; as far as “a plurality” this is a matter of how one operates the device, and not a matter of “method of making” limitations; as was discussed in claim 21, Kim’s pixel is capable of performing a function of QPD since it has the necessary arrangement of parts; whether one actually uses it as QPD, is a matter of operating of the device); and
a deep trench isolation (DTI) structure surrounding photodiodes of a QPD region of the plurality of QPD regions such that the photodiodes are configured to generate a unified photocurrent (part of QPD discussion; the fact that SEP2 does not go all the way down, allows for “unified photocurrent”); and
forming an integrated circuitry die (see FIG. 4 of Tamaki, for example; it shows an “integrated circuitry die” 2), bonded with the sensor die (1), configured to receive the unified photocurrent (as was discussed above, Kim’s pixel is capable of producing “unified photocurrent”; Tamaki shows that results of operations of die 1are then sent to die 2 (see electrical connections in FIG. 4 and related text); thus it is capable of performing the function); and
perform phase detection autofocus (PDAF) for the image sensor device based on the unified photocurrent (this is a matter of operating device, and is not a matter of “method of making”; in other words, this is a matter of programming, which does not carry patentable weight in a claim drawn to method of making).
Regarding claim 29, the combined method of Li, Tamaki and Kim disclose in cited figures and related text, e.g., wherein the photodiodes are included in pixel sensors of the QPD region (as was discussed above, Kim’s pixel is “QPD capable”); and wherein the pixel sensors are arranged in a 2x2 grid on the sensor die (pixels are notoriously well-known to be arranged in huge arrays (such as, 100x100, for example), of which, 2x2 is a subgroup thereof; thus meeting limitations; also, see FIG. 13a of Kim, which shows 2x2 subgroup under a single micro lens, if this is what Applicant is attempting to claim).
Regarding claim 30, the combined method of Li, Tamaki and Kim disclose in cited figures and related text, e.g., wherein the DTI structure comprises: a first DTI portion that surrounds an outer perimeter of the 2x2 grid (this is what FIG. 4B of Kim shows; SEP1 goes all the way around the outer edge of four micro lenses in FIG. 13A); and a second DTI portion in between the pixel sensors in the 2x2 grid (another SEP1, this one goes in-between the four micro-lenses, in vertical cross shape, in FIG. 13A).
Regarding claim 31, the combined method of Li, Tamaki and Kim disclose in cited figures and related text, e.g., wherein the DTI structure comprises: a third DTI portion in between the photodiodes of the pixel sensors (this is what SEP2 does; it is under a singular micro lens going in cross shape in FIG. 13A).
Regarding claim 32, the combined method of Li, Tamaki and Kim disclose in cited figures and related text, e.g., wherein a depth of the first DTI portion and a depth of the second DTI portion are approximately a same depth (they are both SEP1; just in different part of device); and
wherein a depth of the third DTI portion is less than the depth of the first DTI portion and the depth of the second DTI portion (SEP2 is smaller depth, as shown in FIG. 4B).
Conclusion
Additional references (if any) are cited on the PTO-892 as disclosing similar features to those of the instant invention.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Alexander Belousov whose telephone number is (571)-272-3167. The examiner can normally be reached on 10 am-4 pm. If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, Jeff Natalini can be reached on 571-272-2266. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Alexander Belousov/Patent Examiner, Art Unit 2894
12/27/25
/Mounir S Amer/Primary Examiner, Art Unit 2818