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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 01/16/2025. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 20 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 20 recited the limitation “the partial depth isolation structure is further formed over a back-side surface of the substrate and covering the full depth isolation structure” is unclear. Only a liner formed over a back-side surface of the substrate and covering the full depth isolation structure.
Claim Rejections - 35 USC § 102
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.
Claim(s) 15-27 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Chiang et al. (US 2023/0317757).
As for claim 15, Chiang et al. disclose in Figs. 1-18 and the related text a method of forming an image sensor, the method comprising:
forming a photodetector 122 within a substrate 104, wherein the substrate has a back-side surface 104b that is opposite from a front-side surface 104f;
patterning the front-side surface 104f of the substrate to form a full depth isolation structure opening 602 through extending into the substrate (Fig. 6), wherein the full depth isolation structure opening surrounds a portion of the photodetector (Fig. 6);
forming a full depth isolation structure 702 within the full depth isolation structure opening (Fig. 7-8A);
performing a removal process on the back-side surface of the substrate to expose the full depth isolation structure (fig. 11-12);
patterning the back-side surface of the substrate to form a partial depth isolation structure opening 1302 surrounding a portion of the photodetector (Fig. 13), wherein the partial depth isolation structure opening 1302 has a bottom surface that is above the front-side surface of the substrate (Fig. 13), and wherein the partial depth isolation structure opening 1302 is formed between opposing edges of the full depth isolation structure (Fig. 13); and
forming a partial depth isolation structure 136 within the partial depth isolation structure opening.
As for claim 16, Chiang et al. disclose the method of claim 15, wherein the photodetector 122 comprises four sides, and the full depth isolation structure opening 602 is formed surrounding a portion of each of the four sides of the photodetector (Fig. 2B-2C).
As for claim 17, Chiang et al. disclose the method of claim 16, wherein the partial depth isolation structure opening 1302 is formed surrounding a portion of each of the four sides of the photodetector that is different than the portion of each of the four sides of the photodetector occupied by the full depth isolation structure (Fig. 2B-2C).
As for claim 18, Chiang et al. disclose the method of claim 15, wherein a liner 138 is formed within the partial depth isolation structure opening 1302 and separates the full depth isolation structure from the partial depth isolation structure opening (Fig. 16-17), and the partial depth isolation structure 136 is formed on the liner 138 (Figs. 15-17).
As for claim 19, Chiang et al. disclose the method of claim 15, wherein the back-side surface of the substrate is patterned with a dry etch to form the partial depth isolation structure opening [0068], and the method further includes: performing a wet etch on the partial depth isolation structure opening 1302 [0068], wherein the wet etch extends the partial depth isolation structure opening in depth and width (Fig. 14); and forming the partial depth isolation structure 136 within the partial depth isolation structure opening 1302 after performing the wet etch ([0068]-[0071]).
As for claim 20, Chiang et al. disclose the method of claim 15, wherein the partial depth isolation structure 136/138 is further formed over a back-side surface of the substrate and covering the full depth isolation structure (Fig. 15).
As for claim 21, Chiang et al. disclose in Figs. 1-18 and the related text a method of forming a semiconductor device, the method comprising:
forming a plurality of photodetectors 122 within a substrate 104 having a front-side surface 104f opposite a back-side surface 104b;
forming a floating diffusion node 126 within the substrate (Fig. 10), wherein the plurality of photodetectors 122 are disposed around the floating diffusion node 126 (Fig. 2A);
forming, from the front-side surface of the substrate 104, a first isolation structure 132 disposed between adjacent photodetectors 122 of the plurality of photodetectors and laterally offset from the floating diffusion node 126 (Fig. 1 and 15-17);
thinning the substrate from the back-side surface to expose the first isolation structure (Fig. 11-13), such that the first isolation structure 132 extends through a full thickness of the substrate (Fig. 12-13); and
forming, from the back-side surface of the substrate, a second isolation structure 134 extending toward and aligned overlying the floating diffusion node (Fig. 1 and 14-17), wherein the second isolation structure 134 has a depth less than a depth of the first isolation structure 132 (Fig. 1 and 17).
As for claim 22, Chiang et al. disclose the method of claim 21, further comprising forming a liner layer 138 between the first isolation structure and the second isolation structure (Fig. 1 and 17), wherein the liner layer 138 extends over the back-side surface of the substrate and covers a surface of the first isolation structure exposed by the thinning (Figs. 15-17, [0071]).
As for claim 23, Chiang et al. disclose the method of claim 21, wherein the depth of the first isolation structure 132 is approximately equal to the full thickness of the substrate (Fig. 1 and 16-17).
As for claim 24, Chiang et al. disclose the method of claim 21, wherein a photodetector of the plurality of photodetectors 122 has four sides, wherein the first isolation structure 132 is formed extending substantially parallel with a first side and a second side of the four sides of the photodetector, and wherein the second isolation structure 134 is formed extending substantially parallel with the first side and the second side (Fig. 2B-2C).
As for claim 25, Chiang et al. disclose the method of claim 21, wherein a surface of the second isolation structure 134 at the back-side surface 104b of the substrate 104 is formed with a first width and a surface of the first isolation structure 132 at the back-side surface 104b of the substrate is formed with a second width, wherein (a portion of) the second width is less than (an entire of) the first width.
As for claim 26, Chiang et al. disclose the method of claim 25, wherein a bottom surface of the second isolation structure 134 is formed with a third width and a bottom surface of the first isolation structure 132 has a fourth width, wherein (a portion of) the third width is less than (an entire of) the fourth width.
As for claim 27, Chiang et al. disclose the method of claim 21, wherein the floating diffusion node 126 is formed laterally surrounded by the first isolation structure 132 (Fig. 1-17).
Reason for Allowance
Claims 28-34 are allowed.
Claims 28-34 are allowed over the references of record because none of these references disclosed or can be combined to yield the claimed invention such as “performing an extension etch on the first partial depth isolation opening to form a second partial depth isolation opening laterally to a sidewall of the first isolation structure; and forming a second isolation structure within the second partial depth isolation opening, wherein the second isolation structure has a depth less than a depth of the first isolation structure”, as recited in claim 28. Claims 29-34 depend among allowable claim 28.
The following is an examiner's statement of reasons for allowance: Lee appears to be the closest prior art reference. However, this reference fails to teach said limitations. Prior art of record fails to teach or suggest to incorporate these limitations into Lee to arrive at the claimed device.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TRANG Q TRAN whose telephone number is (571)270-3259. The examiner can normally be reached Monday-Thursday (9am-4pm).
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/TRANG Q TRAN/Primary Examiner, Art Unit 2811
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