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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on June 24, 2026 has been entered.
Status of the Claims
Amendment filed June 24, 2026 is acknowledged. Claim 1 has been amended. Non-elected Species, claims 13-14 have been withdrawn from consideration. Claims 1-20 are pending.
Examination on merits of the elected Species, claims 1-12 and 15-20 follows.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-2, 4-12, 15-18 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over OKAWA (WO2021/256086) in view of CHOI et al. (US. Pub. No. 2018/0219040) both of record.
With respect to claim 1, OKAWA teaches an image sensor substantially as claimed including:
a plurality of sensor unit (3b);
a sensing portion (23, includes photoelectric conversion element APD, not shown) disposed within each of the sensor unit (3b); and
an isolation structure corresponding to the sensing portion, comprising:
a first deep trench isolation (DTI) structure (28) surrounding the sensor unit (3b) from top view; and
a second deep trench isolation structure (29) laterally enclosed by the first deep trench isolation structure (28),
wherein the second deep trench isolation structure (29) is located close to a corner of the sensor unit (3b) defined by the first deep trench isolation structure (28), wherein only one second deep trench structure (29) corresponding to each sensing portion, and the corner is located far away from a light spot (37), and
wherein the light spot (37) is converged above the first deep trench structure (28) at a center of a group (PU) of sensor units (3b), the second deep trench isolation structure (29) is asymmetrical with respect to a horizontal middle line or a vertical middle line within the sensor unit (3b),
wherein the first deep trench isolation structure (29) laterally separates each sensing portion (photoelectric conversion element APD, not shown). (See FIGs. 3b, 6).
Note that, OKAWA, ¶ [0068], discloses: “Furthermore, not illustrated in detail, each photoelectric conversion section 23 of the plurality of photoelectric conversion sections 23 includes, for example, an avalanche photo diode (APD) element as a photoelectric conversion element, …”.
Thus, OKAWA is shown to teach all the features of the claim with the exception of explicitly disclosing the first deep trench isolation structure laterally separates each sensing portion (photoelectric conversion element).
However, CHOI teaches an image sensor including:
a plurality of sensor unit (S);
a sensing portion (110, photoelectric device) disposed within each of the sensor unit (S); and
an isolation structure corresponding to the sensing portion (110), comprising:
a first deep trench isolation (DTI) structure (130) surrounding the sensor unit (S) from top view, wherein the first deep trench isolation structure (130) laterally separates each sensing portion (110). (See FIGs. 11,12).
Therefore, it would have been obvious to one having ordinary skill in the art at the time of invention was made to form the image sensor of OKAWA having the first deep trench isolation structure laterally separates each sensing portion as taught by CHOI for the same intended purpose of isolating each sensor unit from one another, thus cross talk is prevented.
With respect to claim 2, the first deep trench isolation structure (28) of OKAWA defines an area of the sensor unit (3b), and a diagonal line across the area of the sensor unit (3b) intersects with the second deep trench isolation structure (29).
With respect to claim 4, two or more of the sensor units (3b) of OKAWA constitute a group (PU) of sensor units.
With respect to claim 5, the group (PU) of sensor units (3b) of OKAWA has a center point (28a) from top view, and two or more of the second deep trench isolation structures (29) of the group of sensor units (3b) are symmetrical with respect to the center point (28a).
With respect to claim 6, the image sensor of OKAWA further comprises a micro-lens (35) disposed correspondingly on the group (PU) of sensor units.
With respect to claim 7, in view of CHOI, the image sensor further includes the top film (230) disposed conformally on the micro-lens (220).
With respect to claim 8, in view of CHOI, a refractive index of the top film (230) is lower than a refractive index of the micro-lens (220).
With respect to claim 9, in view of CHOI, the refractive index of the top film (230) is higher than a refractive index of air.
With respect to claim 10, the group of sensor units of OKAWA further comprises a color filter layer (33) disposed on two or more of the sensing portions. (See FIG. 4A).
With respect to claim 11, the image sensor of OKAWA further comprises a partition grid structure (32) laterally surrounding the color filter layer (33) of the group of sensor units.
With respect to claim 12, the image sensor of OKAWA further comprising a light shield structure (31) embedded within the partition grid structure (32).
With respect to claim 15, the second deep trench isolation structure (29) of OKAWA is a rectangular shape, a square shape, an arc shape, or an L-shape from top view.
With respect to claim 16, the second deep trench isolation structure (29) of OKAWA extends from the corner toward at least one of adjacent corners or a diagonal corner of the sensor unit.
With respect to claim 17, the sensing portion and the isolation structure of OKAWA are embedded within a substrate (20).
With respect to claim 18, the first deep trench isolation structure (28) of OKAWA has a first depth extending into the substrate (20), and the second deep trench isolation structure (29) has a second depth extending into the substrate, wherein the first depth is larger than the second depth.
With respect to claim 20, a refractive index of the second deep trench structure (29) of OKAWA is between 1.3 and 2.5.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over OKAWA ‘086 and CHOI ‘040, as applied to claim 2 above and further in view of CHOU et al. (US. Pub. No. 2021/0183922) of record.
OKAWA, in view of CHOI, teaches the image sensor as described in claim 2 above including: an area of the second deep trench isolation structure (29) from top view is less than 35% of the area of the sensor unit (3b), and a critical dimension of a width of the second deep trench isolation structure (29) from top view.
Thus, OKAWA and CHOI are shown to teach all the features of the claim with the exception of explicitly disclosing the critical dimension of the width of the second deep trench isolation structure being less than 180 nm.
The claimed an area of the second deep trench being less than 35% of the area of the sensor unit, and of a width of the second deep trench isolation structure being less than 180 nm do not appear to be critical.
Note that the specification contains no disclosure of either the critical nature of the claimed width of less than 180 nm of any unexpected results arising therefrom. Where patentability is aid to based upon particular chosen dimension or upon another variable recited in a claim, the Applicant must show that the chosen dimension are critical. In re Woodruff, 919 F.2d 1575, 1578, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990).
However, CHOU teaches an image sensor including:
an area of second deep trench isolation structure (142) from top view is less than 35% of the area of the sensor unit (104), and a critical dimension of a width of the second deep trench isolation structure (142) from top view being 0.1 µm to 1.5 µm, hence includes the claimed of less than 180 nm. (See FIGs. 3, 5A, 7B).
Therefore, it would have been obvious to one having ordinary skill in the art at the time of invention was made to form the second deep trench isolation of OKAWA, in view of CHOI, having the critical dimension of the width as taught by CHOU for the same intended purpose of scattering the light without departing from the scope of either.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over OKAWA ‘086 and CHOI ‘040, as applied to claim 18 above, and further in view of CHIANG et al. (US. Pub. No. 2021/0265414) of record.
OKAWA, in view of CHOI, teaches the image sensor as described in claim 18 above including the second deep trench isolation structure (29) has a second depth extending into the substrate, less than the first depth.
Thus, OKAWA and CHOI are shown to teach all the features of the claim with the exception of explicitly disclosing the second depth.
However, CHIANG teaches an image sensor including a second deep trench isolation structure (230) has a second depth (h1) extending into substrate (212), wherein the second depth (h1) is less than 1 µm. (See FIG. 6).
Therefore, it would have been obvious to one having ordinary skill in the art at the time of invention was made to form the second deep trench isolation structure of OKAWA, in view of CHOI, having the second depth as taught by CHIANG for the same intended purpose of providing the longer light traveling distance.
Response to Arguments
Applicant’s arguments with respect to amended claim has been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
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/ANH D MAI/Primary Examiner, Art Unit 2893
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