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 .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Response to Amendment
The amendment filed on 11 May, 2026 has been fully considered and entered.
Response to Arguments
Regarding the rejection under 35 U.S.C. 112(b): As indicated in the Examiner’s interview summary mailed on 29 April, 2026, the previously raised 112(b) rejection relating to the terms “substantially” and “about” were discussed in the interview, when Applicants pointing to paragraph 0010 as reason to withdraw the rejection. Upon further consideration in view of this paragraph, the terms “substantially” and “about” are not considered indefinite and the rejection is withdrawn.
Regarding the rejection of claim 15 under 35 U.S.C. 102(a)(1): Applicant's arguments filed 11 May, 2026 have been fully considered but they are not persuasive.
Applicant asserts that Poon et al. (US 2017/0254955; hereinafter Poon) fails to disclose “the third n-type region comprises p-type dopants having a substantially same concentration as p-type dopants in the p-type region” since the curved portion adjacent to a second edge 138 and opposite to a first edge 136 is predominantly undoped after a first implantation step.
Examiner disagrees. As taught in Poon paragraph 0068, the portion of the rib 125 that was shielded by the first mask 160 comprises a transition zone 199 that may include some amount of the first dopant species, decreasing from the edge of the shielding towards the second edge 138. The junction shown in Fig. 5F is located where the concentration of n-type dopants is equal to the concentration of the p-type dopants already present in the transition zone. On one side of said junction, close to the junction, the concentration of p-type dopants is a substantially same concentration as the p-type dopants on the other side of the junction, close to the junction. The term “substantially”, not being limited to a particular threshold value, is evaluated on the basis that the transition zone has a concentration of p-type dopants that decreases from the edge, so two points located near each other will have a similar, i.e. substantially same, concentration of p-type dopants. Therefore, the argument is unpersuasive. Examiner notes that even if “substantially” were limited to a particular threshold, as two points approach each other, the concentration would converge to a same concentration evaluated with respect to any threshold. For these reasons, the rejection is maintained.
Additionally, upon further consideration, Examiner considers that while the amendment to claim 9 adds new limitations and therefore overcame the rejection as written, a new interpretation of “exposing a range over a width of the optical waveguide” has been applied in the rejection of claim 9 below, also relying on Tu.
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.
Claims 15-17 and 19-20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Poon et al. (US 2017/0254955; hereinafter Poon).
Regarding claim 15: Poon disclosesA structure (see Fig. 5f), comprising: a ridge (Fig. 5f, rib 125) on a substrate (Fig. 5f, slab of Si from which rib 125 extends); a P-N junction (see Fig. 5f, U-shaped P-N junction; see paragraph 0065) in the ridge, wherein the P-N junction comprises: a first n-type region (see paragraphs 0024-0026 and 0071, and see Fig. 5f lower arm 143) in the substrate; a p-type region on the first n-type region (see paragraphs 0024-0026 and 0068, and see Fig. 5f, first dopant region 132); a second n-type region on the p-type region (see paragraphs 0024-0026 and 0073, and see Fig. 5f, upper arm 142); and a third n-type region connecting the first and second n-type regions (Fig. 5f, curved portion 144 and paragraph 0073), wherein the third n-type region comprises p-type dopants having a substantially same concentration as p-type dopants in the p-type region (see paragraph 0068; the transition zone is considered to have substantially the same concentration of p-type dopants as the p-type region, within some threshold, since the concentration varies from an identical concentration to a lower concentration across the transition zone; additionally, “substantially same” is not considered to be limited to a specific concentration range because “substantially” is not limited to a particular cutoff under the broadest reasonable interpretation, nor limited to a particular value by the disclosure, see paragraph 0010); an n-type contact region in the substrate and coupled to the third n-type region (Fig. 5f, contact 135); and a p-type contact region in the substrate and coupled to the p-type region (Fig. 5f, contact 133).
Regarding claim 16: Poon disclosesThe structure of claim 15 (as applied above), wherein the P-N junction has a C-shape (Fig. 5f shows the C-shaped P-N junction).
Regarding claim 17: Poon disclosesThe structure of claim 15 (as applied above), wherein: the p-type region comprises boron (see paragraphs 0079-0081); and the first and second n-type regions comprise phosphorus (see paragraphs 0079-0081).
Regarding claim 19: Poon disclosesThe structure of claim 15 (as applied above), wherein: the third n-type region comprises a first portion adjacent to the first n-type region and a second portion adjacent to the p-type region (Fig. 5f, first portion considered to be the intersection of lower arm 143 and curved portion 144, second portion considered to be the part of the curved portion in line with region 132); and a concentration of the n-type dopants in the first portion is greater than a concentration of n-type dopants in the second portion (since the curved section 144 is the result of the shallow implantation step and the deep implantation step intersecting with the transition region, there is inherently a greater concentration of n-type dopants in the first portion than the second portion).
Regarding claim 20: Poon disclosesThe structure of claim 19 (as applied above), wherein a concentration of the p-type dopants in the second portion is less than the concentration of the n-type dopants in the second portion (see paragraph 0073).
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 9-10, 12, and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Tu et al. (US Patent No. 11,686,991; hereinafter Tu).
Regarding claim 9: Tu disclosesA method, comprising: forming an optical waveguide on a substrate (Fig. 6, steps 2 and 3); and forming an optical modulator in the optical waveguide (Fig. 6 step 4; also col. 10, lines 44-50), comprising: forming a first n-type region under a side surface of the optical waveguide (Fig. 5a, N- section; see col. 8, lines 45-55 and Fig. 5E, sections 110, 111, and 112; see col. 10, lines 20-25); forming a mask on the substrate and exposing a range over a width of the optical waveguide (see Fig. 5B, photoresist exposes a range over a width of the optical waveguide, the range over a width of the optical waveguide extending from the left to the right edge of sections 101, 102, and 103).
Tu further discloses performing an implantation operation based on the mask, wherein said implantation operation forms a second n-type region in the optical waveguide (see col. 9, lines 1-37, particularly possibility 2, lines 26-27; the second n-type region being the dopant of the bottom region 103) and performing an additional implantation operation based on the mask, wherein said additional implantation operation forms a third n-type region in the optical waveguide and on the second n-type region (see col. 9, lines 1-37, particularly possibility 2, lines 26-27; the third n-type region being the dopant of the top region 101); and performing another implantation operation based on the mask, wherein this implantation operation forms a p-type region on the second n-type region and under the third n-type region (see col. 9, lines 1-37, particularly possibility 2, lines 26-27; the p-type dopant being the dopant of the middle region 102). Tu fails to teach that these implantation operations occur in order of first, second, and third, as claimed. However, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to try performing the steps in any order, due to the limited number of possible orders, including in order of the second n-type region, followed by the third n-type region, and finally the p-type region, to obtain the expected result of a product having the same final layered structure disclosed by Tu. See KSR v. Teleflex, 127 S.Ct. 1727 (2007).
Regarding claim 10: Modified Tu teaches the method of claim 9, as applied above. Tu fails to disclose that performing the first implantation operation comprises implanting n-type dopants having an energy greater than energies of dopants implanted during the second and third implantation operations. However, Tu does teach doping different sections of the ridge with different implantation energies (see col. 7, lines 44-47) and that a lower implantation energy results in a doped region at a shallower depth of a columnized section (see col. 12, lines 60-65). Since Tu suggests varying the implantation energies to create the different doped regions and teaches that a lower implantation energy results in a doped region at a shallower depth, it would have been obvious to one of ordinary skill in the art to use the highest implantation energy to form the deepest region, which is the region of the first implantation, and the lowest implantation energy to form the shallower regions, which are the second and third implantations. Therefore, based on Tu’s teachings, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to dope the ridge in such a way that performing the first implantation operation comprises implanting n-type dopants having an energy greater than energies of dopants implanted during the second and third implantation operations, in order to obtain the disclosed layer structure of 101 and 103 being n-type regions and 102 being p-type region.
Regarding claim 12: Modified Tu teaches the method of claim 9, as applied above. While Tu fails to explicitly disclose that performing the first, second, and third implantation operations comprise implanting dopants at a direction substantially perpendicular to the substrate, Fig. 5B strongly suggests that doping the ridge comprises implanting the first n-type dopant (Fig. 5B, section 101), the second n-type dopant (Fig. 5B, section 102), and the p-type dopant (Fig. 5B, section 103) at a direction substantially perpendicular to the substrate. This is suggested by the fact that the mask opening is on top of the ridge and would cast a shadow in any non-perpendicular ion beam. As the sections 101, 102, and 103 are shown to have edges in vertical alignment with the edge of the mask opening, it suggests that the ion beam is substantially perpendicular to the substrate. Additionally, examiner notes that “substantially perpendicular” is not considered to be limited to a specific angle range because “substantially” is not limited to a particular cutoff under the broadest reasonable interpretation, nor limited to a particular value by the disclosure (see paragraph 0010). Therefore, based on the arrangement showed in Tu Fig. 5B, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the method such that performing the first, second, and third implantation operations comprise implanting dopants at a direction substantially perpendicular to the substrate, in order to make these regions share a vertical boundary, as suggested by Tu.
Regarding claim 14: Modified Tu teachesThe method of claim 9 (as applied above), further comprising: forming a first contact region in the substrate and coupled to the first, second, and third n-type regions (see col. 7, lines 29-37 and col. 8, lines 47-56); and forming a second contact region in the substrate and coupled to the p-type region (see col. 7, lines 29-37 and col. 8, lines 47-56).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Tu et al. (US Patent No. 11,686,991; hereinafter Tu) in view of Poon et al. (US 2017/0254955; hereinafter Poon).
Modified Tu teaches the method of claim 9, as applied above. Tu fails to teach that performing the first implantation operation comprises implanting phosphorus at a first dose between about 5x10^13 cm^-2 and about 5x10^14 cm^-2; performing the second implantation operation comprises implanting phosphorus at a second dose between about 5x10^13 cm^-2 and about 5x10^14 cm^-2; and performing the third implantation operation comprises implanting boron at a third dose between about 5x10^13 cm^-2 and about 5x10^14 cm^-2. However, Poon, also related to silicon modulators having irregularly shaped PN junctions (see paragraph 0004), teaches using boron as an p-type dopant and phosphorus as a n-type dopant (see paragraph 0079-0081), including with dosages falling within the claimed ranges of about 5x10^13 cm^-2 and about 5x10^14 cm^-2 for each of the respective dopants (see Table 1). Additionally, examiner notes that “about” zero degrees to “about” 45 degrees is not considered to be limited to a specific angle range because “about” is not limited to a particular cutoff under the broadest reasonable interpretation, nor limited to a particular value by the disclosure (see paragraph 0010). Based on the teachings of Poon, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the method disclosed by Tu such that performing the first implantation operation comprises implanting phosphorus at a first dose between about 5x10^13 cm^-2 and about 5x10^14 cm^-2; performing the second implantation operation comprises implanting phosphorus at a second dose between about 5x10^13 cm^-2 and about 5x10^14 cm^-2; and performing the third implantation operation comprises implanting boron at a third dose between about 5x10^13 cm^-2 and about 5x10^14 cm^-2 in order to use known suitable materials in known suitable ranges for forming pn-junctions to manufacture efficient modulators (see Poon paragraph 0083).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Poon et al. (US 2017/0254955; hereinafter Poon) in view of Zhou et al. (US 2021/0373363; hereinafter Zhou).
Poon discloses the structure of claim 15, as applied above. Poon further discloses that the third n-type region comprises phosphorus (see paragraphs 0079-0081 and 0073). Additionally, in the Poon device, the concentration of the p-type dopants is substantially uniform along a horizontal direction crossing the third n-type region and the p-type region (Fig. 5a shows that the majority of the rib is exposed to a same dosage of p-type dopant; while the concentration is decreasing along the horizontal direction under the shielded portion 160, the rest of the waveguide has a uniform concentration, so it is considered that the concentration of the p-type dopant is substantially uniform along the horizontal direction in Fig. 5a for a portion of the waveguide rib, the horizontal direction being the direction crossing the third n-type region and the p-type region). Poon fails to teach that the third n-type region further comprises arsenic. However, Zhou, also related to modulators having irregularly shaped PN-junctions (see abstract and Fig. 11), teaches that phosphorus and/or arsenic can be used as dopants to form n-doped regions in silicon (see paragraph 0064). It has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the Poon device by including phosphorus and arsenic in the third n-type region, on the basis of their suitability as n-dopants.
Allowable Subject Matter
Claims 1-8 are allowed.
Claim 13 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:
Regarding claim 1: The closest found prior art, Tu and Poon, fail to teach or suggest a method “wherein the mask exposes a top surface, the first side surface, and a second side surface of the ridge”, in combination with the other method steps required by claim 1. Rather, Tu teaches patterning portions of the rib with different masks including openings with a width narrower than the ridge, never teaching a mask which exposes both side surfaces and the top surface of the ridge. Poon does not remedy this deficiency. Therefore, claim 1 is allowed.
Due to the allowable features of claim 1, dependent claims 2-8 are also allowed.
Regarding claim 13: The closest found prior art, Tu and Poon, fail to teach or suggest a method wherein “the opening exposes the side surface and another side surface of the optical waveguide”, in combination with the other method steps required by claim 13. . Rather, Tu teaches patterning portions of the rib with different masks including openings with a width narrower than the ridge, never teaching a mask which exposes both side surfaces. Poon does not remedy this deficiency. Therefore, would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Conclusion
THIS ACTION IS MADE FINAL. 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 Kirsten D Endresen whose telephone number is (703)756-1533. The examiner can normally be reached Monday to Thursday.
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/KIRSTEN D. ENDRESEN/Examiner, Art Unit 2874
/THOMAS A HOLLWEG/Supervisory Patent Examiner, Art Unit 2874
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