Prosecution Insights
Last updated: April 19, 2026
Application No. 18/230,666

GUARD RING STRUCTURE AND COMPONENT STRUCTURE

Final Rejection §103§112
Filed
Aug 07, 2023
Examiner
YECHURI, SITARAMARAO S
Art Unit
2893
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Live Optronics Company Limited
OA Round
2 (Final)
86%
Grant Probability
Favorable
3-4
OA Rounds
2y 1m
To Grant
77%
With Interview

Examiner Intelligence

Grants 86% — above average
86%
Career Allow Rate
744 granted / 867 resolved
+17.8% vs TC avg
Minimal -9% lift
Without
With
+-9.1%
Interview Lift
resolved cases with interview
Fast prosecutor
2y 1m
Avg Prosecution
46 currently pending
Career history
913
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
59.5%
+19.5% vs TC avg
§102
20.3%
-19.7% vs TC avg
§112
15.1%
-24.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 867 resolved cases

Office Action

§103 §112
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 . 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 3, 7, 8 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 3 defines first and second ring widths however they are already in parent claim 1. Claim 7 defines “the first attached guard ring” and “the second attached guard ring” however there is no antecedent basic and their position is defined in dependent claim 8. Claim 8 defines “a first attached guard ring” and “a second attached guard ring” however they are already in parent claim 7. 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. 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. Claim(s) 1, 2 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (CN 105070780 A) hereafter referred to as Chen in view of Ishimura (US 20060186501 A1) In regard to claim 1 Chen teaches a guard ring structure [see Fig. 1 “Referring to FIG. 1, the present invention provides a planar three-step junction avalanche photodiode” “a portion of the cap layer 6 is provided with a coaxial three-stage PN junction, the third ladder PN junction includes a radius gradually increasing width, and the third step PN depth gradually becomes shallow junction 8, PN junction 9 the second step and the first step PN junction 10, the first. second step of PN junction 10 and photodiode 9 for inhibiting junction edge electric field, reducing the area of the active region and improve the frequency characteristic of the device”], which is applicable to an active region [see PN junction, see “p-electrode 11” see plurality of diffusions “the P-type impurity diffused into the capping material in the the first diffusion window to form a predetermined junction depth of the first step a PN junction and the ladder formed PN junction is defined as a junction” “the P type impurity is diffused and formed in the second diffusion window” “the third diffusion window in the P type impurity is diffused”] that is formed by diffusion materials , the guard ring structure comprising: a first attached guard ring [see “PN junction 9 the second step”] disposed at a periphery of the active region; and a second attached guard ring [see “first step PN junction 10”] disposed at a periphery of the first attached guard ring; wherein the first attached guard ring and the second attached guard ring are each [see Fig. 1] an attached guard ring, and form a stepped [see Fig. 1] structure, wherein the first attached guard ring includes a first [see Fig. 1] ring width, the second attached guard ring includes a second [see Fig. 1] ring width, but does not state “including phosphorus and zinc” and “a sum of a width of the active region and the first ring width is less than a sum of the width of the active region and 5um, the second ring width is less than the first ring width”. However see these are standard dopants, see Ishimura paragraph 0044 “p-type impurities such as Zn (zinc) are introduced into the InP window layer 5 to form the shallow p-type diffusion layer region 7a inside the guard ring region 10, as shown in FIG. 5” “After that, p-type impurities such as Zn (zinc) are further introduced into the InP window layer 5 to form the deep p-type diffusion layer region 7b on the inner side of the shallow p-type diffusion layer region 7a, as shown in FIG. 6”. Thus, it 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 to modify Chen to include “including phosphorus and zinc”. The motivation is that standard dopants such as Zn (zinc) are known to give good results as dopant for semiconductor devices. Chen and Ishimura as combined does not state “a sum of a width of the active region and the first ring width is less than a sum of the width of the active region and 5um, the second ring width is less than the first ring width”. However, see Chen “As a specific embodiment, referring to FIG. 1, the radius of the second step PN junction 9 PN junction 5 than the third step to 15 micron radius of 8 width” and “As a specific embodiment, referring to FIG. 1, the radius ratio of the first step PN junction 10 second step PN junction 5 to 15 micron radius of 9 width” thus the range of the widths is the same for 9 and 10. See also that since field is proportional to voltage over distance, and see Poisson’s equation, thus the widths and step heights are result effective for “The implementation of the value range of the radius difference and junction depth difference, it can realize three times an edge electric field intensity of inhibition effect” “The implementation of the value range of the radius difference and junction depth difference can realize secondary edge electric field intensity of inhibition effect”. See Ishimura Fig. 1, Fig. 8 see paragraphs 0057, 0058 see other considerations including breakdown voltage and dark current. See that if active + first ring width < active + 5 um that means that first ring width < 5 um and see above, the dimensions of Chen are very close to this, similarly given that the the range of the widths is the same for 9 and 10, then Chen is actually saying that in some embodiments, second ring width is less than the first ring width. It 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 to use “a sum of a width of the active region and the first ring width is less than a sum of the width of the active region and 5um, the second ring width is less than the first ring width” , since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 105 USPQ 233 In regard to claim 2 Chen and Ishimura as combined teaches wherein a height difference between the first attached guard ring and the active region is a first ring height, a height difference between the second attached guard ring and the first attached guard ring is a second ring height [see “As a specific embodiment, referring to FIG. 1, the radius of the second step PN junction 9 PN junction 5 than the third step to 15 micron radius of 8 width, and the second step junction depth of PN junction 9 junction depth of 8 to 1 micron 0.2 than the third step PN” “As a specific embodiment, referring to FIG. 1, the radius ratio of the first step PN junction 10 second step PN junction 5 to 15 micron radius of 9 width, and the first step junction depth of PN junction 10 junction depth of 9 to 1 micron 0.2 PN than the second step” “the first step junction depth of PN junction than the second step PN junction depth of 0.2 to 1 microns” “said second step junction depth of PN junction than the third step PN junction depth of 0.2 to 1 microns”], and the first ring height and the second ring height range between 0.2 um and 0.4 um. In regard to claim 3 Chen and Ishimura as combined does not state wherein the first attached guard ring has a first ring width, and the second attached guard ring has a second ring width; wherein a ratio of a width value of the second ring width to a sum of a width value of the first ring width and the width value of the second ring width is greater than or equal to 0.25 and less than or equal to 0.5. See that it appears that claim ratio of 0.5 i.e W2/(W1+W2) = 0.5 means that the ring widths are the same. See “As a specific embodiment, referring to FIG. 1, the radius of the second step PN junction 9 PN junction 5 than the third step to 15 micron radius of 8 width” and “As a specific embodiment, referring to FIG. 1, the radius ratio of the first step PN junction 10 second step PN junction 5 to 15 micron radius of 9 width” thus the range of the widths is the same for 9 and 10. See also that since field is proportional to voltage over distance, and see Poisson’s equation, thus the widths and step heights are result effective for “The implementation of the value range of the radius difference and junction depth difference, it can realize three times an edge electric field intensity of inhibition effect” “The implementation of the value range of the radius difference and junction depth difference can realize secondary edge electric field intensity of inhibition effect”. It 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 to use “wherein the first attached guard ring has a first ring width, and the second attached guard ring has a second ring width; wherein a ratio of a width value of the second ring width to a sum of a width value of the first ring width and the width value of the second ring width is greater than or equal to 0.25 and less than or equal to 0.5 ”, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 105 USPQ 233 In regard to claim 4 Chen and Ishimura as combined teaches further comprising a third attached guard ring [see “those skilled in the art should appreciate that the plane type three-step junction avalanche photodiode provided in the present invention, the stepped PN junction knot number is not limited to three-step, on the basis of the embodiments, also can be applied to the two step, fourth step, fifth step, until it can use minimum active area, inhibiting the edge electric field, to reach high frequency characteristics and high gain characteristics”] disposed at a periphery of the second attached guard ring. In regard to claim 5 Chen and Ishimura as combined does not state wherein a height difference between the third attached guard ring and the second attached guard ring is a third ring height, and the third ring height ranges between 0.2 um and 0.4 um. However see “those skilled in the art should appreciate that the plane type three-step junction avalanche photodiode provided in the present invention, the stepped PN junction knot number is not limited to three-step, on the basis of the embodiments, also can be applied to the two step, fourth step, fifth step, until it can use minimum active area, inhibiting the edge electric field, to reach high frequency characteristics and high gain characteristics”, and see the step height that Chen teaches see “As a specific embodiment, referring to FIG. 1, the radius of the second step PN junction 9 PN junction 5 than the third step to 15 micron radius of 8 width, and the second step junction depth of PN junction 9 junction depth of 8 to 1 micron 0.2 than the third step PN” “As a specific embodiment, referring to FIG. 1, the radius ratio of the first step PN junction 10 second step PN junction 5 to 15 micron radius of 9 width, and the first step junction depth of PN junction 10 junction depth of 9 to 1 micron 0.2 PN than the second step” “the first step junction depth of PN junction than the second step PN junction depth of 0.2 to 1 microns” “said second step junction depth of PN junction than the third step PN junction depth of 0.2 to 1 microns”, see also that since field is proportional to voltage over distance, and see Poisson’s equation, thus the widths and step heights are result effective for “The implementation of the value range of the radius difference and junction depth difference, it can realize three times an edge electric field intensity of inhibition effect” “The implementation of the value range of the radius difference and junction depth difference can realize secondary edge electric field intensity of inhibition effect”. It 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 to use “wherein a height difference between the third attached guard ring and the second attached guard ring is a third ring height, and the third ring height ranges between 0.2 um and 0.4 um ”, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 105 USPQ 233 In regard to claim 6 Chen and Ishimura as combined teaches wherein the first ring width is greater than or equal to 4 um [see range is 5 to 15 microns, see “As a specific embodiment, referring to FIG. 1, the radius of the second step PN junction 9 PN junction 5 than the third step to 15 micron radius of 8 width” and “As a specific embodiment, referring to FIG. 1, the radius ratio of the first step PN junction 10 second step PN junction 5 to 15 micron radius of 9 width”] but does not state wherein the third attached guard ring has a third ring width, and a ratio of a width value of the third ring width to a sum of the width value of the second ring width and the width value of the third ring width is greater than or equal to 0.25 and less than or equal to 0.5 . See that it appears that claim ratio of 0.5 i.e W3/(W2+W3) = 0.5 means that the ring widths are the same. See “As a specific embodiment, referring to FIG. 1, the radius of the second step PN junction 9 PN junction 5 than the third step to 15 micron radius of 8 width” and “As a specific embodiment, referring to FIG. 1, the radius ratio of the first step PN junction 10 second step PN junction 5 to 15 micron radius of 9 width” thus the range of the widths is the same for 9 and 10. See also that since field is proportional to voltage over distance, and see Poisson’s equation, thus the widths and step heights are result effective for “The implementation of the value range of the radius difference and junction depth difference, it can realize three times an edge electric field intensity of inhibition effect” “The implementation of the value range of the radius difference and junction depth difference can realize secondary edge electric field intensity of inhibition effect”. It 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 to use “wherein the third attached guard ring has a third ring width, and a ratio of a width value of the third ring width to a sum of the width value of the second ring width and the width value of the third ring width is greater than or equal to 0.25 and less than or equal to 0.5”, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 105 USPQ 233 Claim(s) 7-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (CN 105070780 A) hereafter referred to as Chen in view of Ishimura (US 20060186501 A1) In regard to claim 7 [see 112 rejection] Chen teaches a [see Fig. 1 “Referring to FIG. 1, the present invention provides a planar three-step junction avalanche photodiode” “a portion of the cap layer 6 is provided with a coaxial three-stage PN junction, the third ladder PN junction includes a radius gradually increasing width, and the third step PN depth gradually becomes shallow junction 8, PN junction 9 the second step and the first step PN junction 10, the first. second step of PN junction 10 and photodiode 9 for inhibiting junction edge electric field, reducing the area of the active region and improve the frequency characteristic of the device”] component structure, comprising: an active region [see PN junction, see “p-electrode 11”] that is formed by diffusion materials; and a guard ring structure [“a portion of the cap layer 6 is provided with a coaxial three-stage PN junction, the third ladder PN junction includes a radius gradually increasing width, and the third step PN depth gradually becomes shallow junction 8, PN junction 9 the second step and the first step PN junction 10, the first. second step of PN junction 10 and photodiode 9 for inhibiting junction edge electric field, reducing the area of the active region and improve the frequency characteristic of the device”] disposed at a periphery of the active region, wherein the guard ring structure includes a plurality [see “PN junction 9 the second step”, “first step PN junction 10”] of attached guard rings, and the attached guard rings jointly form a stepped [see Fig. 1] structure, wherein the first attached guard ring [see 112 rejection their position is defined in dependent claim 8] includes a first [see Fig. 1] ring width, the second attached guard ring includes a second [see Fig. 1] ring width, but does not state “including phosphorus and zinc” and “a sum of a width of the active region and the first ring width is less than a sum of the width of the active region and 5 um, the second ring width is less than the first ring width”. However see these are standard dopants, see Ishimura paragraph 0044 “p-type impurities such as Zn (zinc) are introduced into the InP window layer 5 to form the shallow p-type diffusion layer region 7a inside the guard ring region 10, as shown in FIG. 5” “After that, p-type impurities such as Zn (zinc) are further introduced into the InP window layer 5 to form the deep p-type diffusion layer region 7b on the inner side of the shallow p-type diffusion layer region 7a, as shown in FIG. 6”. Thus, it 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 to modify Chen to include “including phosphorus and zinc”. The motivation is that standard dopants such as Zn (zinc) are known to give good results as dopant for semiconductor devices. Chen and Ishimura as combined does not state “a sum of a width of the active region and the first ring width is less than a sum of the width of the active region and 5 um, the second ring width is less than the first ring width”. However, see Chen “As a specific embodiment, referring to FIG. 1, the radius of the second step PN junction 9 PN junction 5 than the third step to 15 micron radius of 8 width” and “As a specific embodiment, referring to FIG. 1, the radius ratio of the first step PN junction 10 second step PN junction 5 to 15 micron radius of 9 width” thus the range of the widths is the same for 9 and 10. See also that since field is proportional to voltage over distance, and see Poisson’s equation, thus the widths and step heights are result effective for “The implementation of the value range of the radius difference and junction depth difference, it can realize three times an edge electric field intensity of inhibition effect” “The implementation of the value range of the radius difference and junction depth difference can realize secondary edge electric field intensity of inhibition effect”. See Ishimura Fig. 1, Fig. 8 see paragraphs 0057, 0058 see other considerations including breakdown voltage and dark current. See that if active + first ring width < active + 5 um that means that first ring width < 5 um and see above, the dimensions of Chen are very close to this, similarly given that the range of the widths is the same for 9 and 10, then Chen is actually saying that in some embodiments, second ring width is less than the first ring width. It 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 to use “a sum of a width of the active region and the first ring width is less than a sum of the width of the active region and 5 um, the second ring width is less than the first ring width” , since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 105 USPQ 233 In regard to claim 8 Chen teaches wherein the guard ring structure includes a first attached guard ring [see “PN junction 9 the second step”] and a second attached guard ring [see “first step PN junction 10”], the first attached guard ring is disposed at the periphery [see Fig. 1] of the active region, and the second attached guard ring is disposed at a periphery [see Fig. 1] of the first attached guard ring. In regard to claim 9 Chen teaches wherein the guard ring structure further includes [“those skilled in the art should appreciate that the plane type three-step junction avalanche photodiode provided in the present invention, the stepped PN junction knot number is not limited to three-step, on the basis of the embodiments, also can be applied to the two step, fourth step, fifth step, until it can use minimum active area, inhibiting the edge electric field, to reach high frequency characteristics and high gain characteristics”] a third attached guard ring disposed at a periphery of the second attached guard ring. Response to Arguments Applicant's arguments filed 12/23/2025 have been fully considered but they are not persuasive. On page 1-3 the Applicant argues “Applicant has amended independent claim 1 (and 7) to recite "which is applicable to an active region that is formed by diffusion materials including phosphorus and zinc," and "wherein the first attached guard ring includes a first ring width, the second attached guard ring includes a second ring width, a sum of a width of the active region and the first ring width is less than a sum of the width of the active region and 5um, the second ring width is less than the first ring width." ” “Chen (see, Chen, [0036]) discloses that:"[f]urther, the radius of the radius ratio second ladder PN junction of described first ladder PN junction is wide 5 ~ 15 um," which does not overlap with the feature "the first ring width is greater than or equal to 4um, and the first ring width is less than 5um" recited in the amended claim 1”. The Examiner responds that the dimensions of Chen are very close to that claimed, see the rejection, the widths are result effective variables, discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 105 USPQ 233 On page 2 the Applicant argues “To one skilled in the art, the "p type impurity" means that "A p-type impurity is a trivalent (Group 3) element like Boron, Aluminum, or Gallium, added to a pure semiconductor (like Silicon) to create extra "holes" (missing electrons) in its crystal structure, making the material "p- type" (positive-type) where holes are the majority charge carriers, enhancing electrical conductivity for electronics". Furthermore, the first However, the first attached ring and the second attached ring and the active region are formed on the diffusion layer that is formed by diffusion materials including phosphorus and zinc”. The Examiner responds that Zinc doping is common in the art, see the secondary reference provided. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to SITARAMARAO S YECHURI whose telephone number is (571)272-8764. The examiner can normally be reached M-F 8:00-4:30 PM. 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, Britt D Hanley can be reached at 571-270-3042. 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. /SITARAMARAO S YECHURI/ Primary Examiner, Art Unit 2893
Read full office action

Prosecution Timeline

Aug 07, 2023
Application Filed
Sep 22, 2025
Non-Final Rejection — §103, §112
Dec 23, 2025
Response Filed
Mar 03, 2026
Final Rejection — §103, §112 (current)

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