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 .
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Drawings
The drawings are objected to as failing to comply with 37 CFR 1.84(p)(5) because they do not include the following reference sign(s) mentioned in the description: Fig. 2 does not include “an additional low doped P—implant” described in pgs. 12-13 corresponding to this figure. Rather, Fig. 2 appears to be a duplicate of Fig. 1 instead of an illustration of the embodiment described on pgs. 12-13. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Objections
Claims 1, 3, and 7 are objected to because of the following informalities: See below. Appropriate correction is required. No actual change to the claim language has been applied during examination of the instant set of claims.
Claim 1 is objected to because of the following informalities:
“a second conductivity type” in lines 11-12 (i.e., the second instance of the term). For the sake of compact prosecution, claim 1 is interpreted in the instant Office action as follows: “a second conductivity type of a higher doping concentration” is found to be a typographical error and is believed to be equivalent to “the second conductivity type of a higher doping concentration” based on antecedence for this term earlier in claim 1, line 11.
“the second conductivity” in lines 12-13. For the sake of compact prosecution, claim 1 is interpreted in the instant Office action as follows: “the second conductivity” is found to be a typographical error and is believed to be equivalent to “the second conductivity type” based on antecedence for this term earlier in claim 1, line 11.
“laterally space islands” in line 13. For the sake of compact prosecution, claim 1 is interpreted in the instant Office action as follows: “laterally space islands” is found to be a typographical error and is believed to be equivalent to “laterally spaced islands” based on antecedence for this term earlier in claim 1, line 9.
“the doping concentration of the second conductivity of the at least two laterally space islands” in lines 12-13 (i.e., the first instance of the term). For the sake of compact prosecution, claim 1 is interpreted in the instant Office action as follows: “the doping concentration of the second conductivity of the at least two laterally space islands” is found to be a typographical error and is believed to be equivalent to “a doping concentration of the second conductivity of the at least two laterally space islands”.
Claim 3 is objected to because of the following informalities:
“a doping concentration of any of the at least two laterally spaced islands” in lines 4-5. For the sake of compact prosecution, claim 3 is interpreted in the instant Office action as follows: “a doping concentration of any of the at least two laterally spaced islands” is found to be a typographical error and is believed to be equivalent to “the doping concentration of any of the at least two laterally spaced islands” based on antecedence for this term in claim 1.
“a doping concentration of the surface layer” in line 5. For the sake of compact prosecution, claim 3 is interpreted in the instant Office action as follows: “a doping concentration of the surface layer” is found to be a typographical error and is believed to be equivalent to “the doping concentration of the surface layer” based on antecedence for this term in claim 1.
Claim 7 is objected to because of the following informalities:
“in lateral direction” in lines 2-3. For the sake of compact prosecution, claim 7 is interpreted in the instant Office action as follows: “in lateral direction” is found to be a typographical error and is believed to be equivalent to “in a lateral direction”.
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.
Claims 4 (and dependent claim 5 dependent therefrom), 5, and 12 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.
The claims are generally narrative and indefinite, failing to conform with current U.S. practice. They appear to be a literal translation into English from a foreign document and are replete with grammatical and idiomatic errors.
Claim 4 recites the limitation “the semiconductor material” in line 2. There is insufficient antecedent basis for this limitation in the claim. For the sake of compact prosecution, claim 4 is interpreted in the instant Office action as follows: “the semiconductor material” is equivalent to “the semiconductor body” based on this term in claim 1, line 10 describing similar dimensions. This interpretation is to be confirmed by applicant in the next office action.
Claim 5 recites the limitation “the semiconductor material” in line 2. There is insufficient antecedent basis for this limitation in the claim. For the sake of compact prosecution, claim 5 is interpreted in the instant Office action as follows: “the semiconductor material” is equivalent to “the semiconductor body” based on this term in claim 1, line 10 describing similar dimensions. This interpretation is to be confirmed by applicant in the next office action.
Claim 12 recites the limitation “the second surface layer” in line . There is insufficient antecedent basis for this limitation in the claim. For the sake of compact prosecution, claim 12 is interpreted in the instant Office action as follows: “the second surface layer” is referring to Figs. 1-3: surface layers N/P— at the first major surface. This interpretation is to be confirmed by applicant in the next office action.
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 1-10, 13-18 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kono (US 20200279940 A1).
Regarding claim 1, Kono discloses a vertically oriented semiconductor device (Fig. 7) comprising:
a semiconductor body (10; [0028]: “silicon carbide”);
a first major surface (P1);
a substrate (14);
a first region (22 combined with 24 and 38a/34/38b) provided on the substate and having a first conductivity type (n-type is shown), the first region having a first doping concentration (the doping of 22, 24, 34, and 38a/38b cited here respectively: portion 22 is [0031]: “equal to or greater than 1×1018 cm−3 and equal to or less than 1×1021 cm−3”; portion 24 is [0033]: “equal to or greater than 4×1014 cm−3 and equal to or less than 1×1017 cm−3”; portion 34 is [0053]: “equal to or greater than 5×1016 cm−3 and equal to or less than 2×1017 cm−3”; portions 38a/38b are [0064]: “5×1016 cm−3 and equal to or less than 2×1017 cm−3”. Note: the collection of ranges cited here is summarized as 4×1014 cm−3 to 2×1017 cm−3 and 1×1018 cm−3 to 1×1021 cm−3);
a metal layer (12a; [0077]: “nickel silicide or titanium silicide”) provided on top of the first region (See annotated figure for direction designation), so that a Schottky junction ([0055]: “a Schottky junction”) is provided between the first region and the metal layer (sandwiched vertically between, the junction being the interface of 12/36);
at least two laterally spaced islands (26a/26b) extending from the first major surface downward (See annotated figure for direction designation) into the semiconductor body, the at least two laterally spaced islands having a second conductivity type (p-type is shown) and further comprising an implant (the implant of inner islands 32a/32b) of a second conductivity type (p-type is shown) of a higher doping concentration ([0047]: “impurity concentration…higher than”) than the doping concentration of the second conductivity of the at least two laterally space islands;
and wherein the first region has a surface layer (36 with 40a/40b) that comprises dopants of the second conductivity type (p-type is shown) at a concentration in a range of 5% - 20% of the first doping concentration (the concentration of portion 36 is [0056]: “equal to or greater than 1×1017 cm−3 and equal to or less than 2×1018 cm−3”. Note: this doping concentration range fully encompasses the claimed numerical relation of concentrations, because this range includes all numbers within 5-20% of the first concentration of layer 22 of layers 22/24/34/38a/38b.).
Illustrated below is a marked and annotated figure of Fig. 7 of Kono.
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Regarding claim 7, Kono discloses the vertically oriented semiconductor device in accordance with claim 1 (Fig. 7), wherein the surface layer has a doping concentration that is non-uniform in lateral direction (the surface layer includes portions 40a/40b which are p- concentration, and middle portion 36 which is p concentration, thus, “non-uniform”).
Regarding claim 8, Kono discloses the vertically oriented semiconductor device in accordance with claim 7 (Fig. 7), wherein the surface layer has a doping concentration that is the highest in a lateral middle part of the surface layer (portion 36 is the middle part, with concentration [0056]: “equal to or greater than 1×1017 cm−3 and equal to or less than 2×1018 cm−3”), and wherein the doping concentration decreases laterally (portions 40a/40b have lower concentration than 36; [0119]: “equal to or greater than 5×1016 cm−3 and equal to or less than 1×1018 cm−3”) in a direction towards the at least two laterally spaced islands.
Regarding claim 9, Kono discloses the vertically oriented semiconductor device in accordance with claim 1 (Fig. 7), wherein the surface layer has a second doping concentration in a range of 7,5% - 12,5% of the first doping concentration (the concentration of portion 36, [0056]: “equal to or greater than 1×1017 cm−3 and equal to or less than 2×1018 cm−3”. Note: this doping concentration range for layer 36 fully encompasses the claimed numerical relation of concentrations, because this range includes all numbers within 7.5-12% of the first concentration of layer 22 of layers 22/24/34/38a/38b.).
Regarding claim 10, Kono discloses the vertically oriented semiconductor device in accordance with claim 1 (Fig. 7), wherein the surface layer has a depth (d, See Fig. 1 for measurement annotation) into the semiconductor device from the first major surface of between 50nm – 200nm ([0108]: “equal to or greater than 50 nm and equal to or less than 200 nm”).
Regarding claim 13, Kono discloses the vertically oriented semiconductor device in accordance with claim 1 (Fig. 7), wherein any of the at least two laterally spaced islands comprises (each comprises…): an inner island (32a/32b) of the second conductivity type (p-type is shown), the inner island being encompassed by the corresponding island (fully encompassed), and wherein the inner island has a doping concentration that is higher than ([0047]: “impurity concentration…higher than”) a doping concentration of the corresponding island.
Regarding claim 14, Kono discloses the vertically oriented semiconductor device in accordance with claim 1 (Fig. 7), wherein the semiconductor device is a diode selected from the group consisting of: a Merged PIN Schottky diode, and a Schottky diode (a Schottky diode is shown at 12/36/34).
Regarding claim 15, Kono discloses the vertically oriented semiconductor device in accordance with claim 1 (Fig. 7), wherein the semiconductor device is a power semiconductor device (a Schottky diode is shown at 12/36/34, which is capable of flowing current in at least one direction, thus “a power semiconductor device”).
Regarding claim 16, Kono discloses the vertically oriented semiconductor device in accordance with claim 1 (Fig. 7), wherein the first doping concentration of the first region is non-uniform in a lateral direction (the periodic lateral spacing of portions 38a/34/38b include “n” doping, while the portions only including 22/24 only include “n-“ doping. Thus, the combination of these portions of the first region is “non-uniform” in the lateral direction).
Regarding claim 17, Kono discloses the vertically oriented semiconductor device in accordance with claim 1 (Fig. 7), wherein the semiconductor body comprises Silicon Carbide (SiC) ([0028]: “silicon carbide”).
Regarding claim 18, Kono discloses a vertically oriented semiconductor body in accordance with claim 1 (Fig. 7), wherein the first conductivity is N-type conductivity (n-type is shown and has been cited in the claim 1 rejection), and wherein the second conductivity is P-type conductivity (p-type conductivity is shown and has been cited in the claim 1 rejection).
Note that claim 1 was previously addressed above, however, it’s being addressed differently here based on the reading of the reference, particularly to the assignment of the surface layer in order to address the dependent claim 3.
Regarding claim 1, Kono discloses a vertically oriented semiconductor device (Fig. 9) comprising:
a semiconductor body (10; [0028]: “silicon carbide”);
a first major surface (P1);
a substrate (14);
a first region (22 combined with 24 and 38a/34/38b) provided on the substate and having a first conductivity type (n-type is shown), the first region having a first doping concentration (the doping of 22, 24, 34, and 38a/38b cited here respectively: portion 22 is [0031]: “equal to or greater than 1×1018 cm−3 and equal to or less than 1×1021 cm−3”; portion 24 is [0033]: “equal to or greater than 4×1014 cm−3 and equal to or less than 1×1017 cm−3”; portion 34 is [0053]: “equal to or greater than 5×1016 cm−3 and equal to or less than 2×1017 cm−3”; portions 38a/38b are [0064]: “5×1016 cm−3 and equal to or less than 2×1017 cm−3”. Note: the collection of ranges cited here is summarized as 4×1014 cm−3 to 2×1017 cm−3 and 1×1018 cm−3 to 1×1021 cm−3);
a metal layer (12a; [0077]: “nickel silicide or titanium silicide”) provided on top of the first region (See annotated figure for direction designation), so that a Schottky junction ([0055]: “a Schottky junction”) is provided between the first region and the metal layer (sandwiched vertically between, the junction being the interface of 12/36);
at least two laterally spaced islands (26a/26b) extending from the first major surface downward (See annotated figure for direction designation) into the semiconductor body, the at least two laterally spaced islands having a second conductivity type (p-type is shown) and further comprising an implant (the implant of inner islands 32a/32b) of a second conductivity type (p-type is shown) of a higher doping concentration ([0047]: “impurity concentration…higher than”) than the doping concentration of the second conductivity of the at least two laterally space islands;
and wherein the first region has a surface layer (36) that comprises dopants of the second conductivity type (p-type is shown) at a concentration in a range of 5% - 20% of the first doping concentration (the concentration of portion 36 is [0056]: “equal to or greater than 1×1017 cm−3 and equal to or less than 2×1018 cm−3”. Note: this doping concentration range fully encompasses the claimed numerical relation of concentrations, because this range includes all numbers within 5-20% of the first concentration of layer 22 of layers 22/24/34/38a/38b.).
Illustrated below is a marked and annotated figure of Fig. 9 of Kono.
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Regarding claim 2, Kono discloses the vertically oriented semiconductor device in accordance with claim 1 (Fig. 9), wherein the surface layer does not extend up to any of the at least two laterally spaced islands (Surface layer 36 is separated from islands 26a/26b by second surface layer 44a/44b, thus 36 “does not extend up to” 26a/26b.).
Regarding claim 3, Kono discloses the vertically oriented semiconductor device in accordance with claim 2 (Fig. 9), further comprising a second surface layer (44a/44b) that is provided in between (laterally between) the surface layer and any of the at least two laterally spaced islands, and wherein the second surface layer has a dopant concentration ([0153]: “equal to or greater than 1×1017 cm−3 and equal to or less than 4×1017 cm−3”) that is lower than a doping concentration of any of the at least two laterally spaced islands (The concentration ranges of 2nd surface layer 44a/44b and islands 26a/26b overlap. Thus, there are a plurality of concentrations capable of satisfying the claimed concentration configuration.) and higher than a doping concentration of the surface layer (The concentration ranges of 2nd surface layer 44a/44b and surface layer 36 overlap. Thus, there are a plurality of concentrations capable of satisfying the claimed concentration configuration.).
Regarding claim 4 as noted in the 112(b) rejection, Kono discloses the vertically oriented semiconductor device in accordance with claim 3 (Fig. 9), wherein the second surface layer extends deeper into the semiconductor body than the surface layer (44a/44b are deeper within 10 than 36).
Regarding claim 5 as noted in the 112(b) rejection, Kono discloses the vertically oriented semiconductor device in accordance with claim 4 (Fig. 9), wherein the second surface layer extends deeper into the semiconductor body by 5% - 50% than the surface layer (extension starts at depth d of layer 36, annotated in Fig. 1, which is 50-200 nm, [0058]; and extension ends at the same deepest depth of 26a, which is 0.5-1.0 µm. This shallowest and deepest depth overlaps the claimed extension depth and therefore at least a portion of “the second surface layer extends deeper” in the claimed range).
Regarding claim 6, Kono discloses the vertically oriented semiconductor device in accordance with claim 2 (Fig. 9), further comprising a second surface layer (44a/44b) that is provided in between (laterally between) the surface layer and any of the at least two laterally spaced islands, and wherein the second surface layer has the first conductivity type (n-type is shown).
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.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Kono as applied to claim 1 above, and further in view of Suvorov (US 20180069083 A1).
Regarding claim 11, Kono discloses the vertically oriented semiconductor device in accordance with claim 1 (Fig. 7), wherein the first region comprises: an epitaxial layer (24 is cited here as a generic layer) provided on the substrate, and an NCS layer (38a/34/38b) provided on top of the epitaxial layer, wherein the NCS layer has the first doping concentration (this concentration is cited in the claim 1 rejection; [0053]), and wherein the epitaxial layer has a doping concentration that is lower than the first doping concentration ([0033]: “equal to or greater than 4×1014 cm−3 and equal to or less than 1×1017 cm−3”. Note: this cited range for layer 24 includes an endpoint capable of satisfying the claimed “lower” concentration configuration.).
Kono fails to teach the cited layer (Fig. 7: layer 24) being formed by epitaxy because Kono is silent regarding the method of forming this layer. Thus, Kono fails to teach:
“wherein the first region comprises: an epitaxial layer provided on the substrate, and an NCS layer provided on top of the epitaxial layer, wherein the NCS layer has the first doping concentration, and wherein the epitaxial layer has a doping concentration that is lower than the first doping concentration”.
Suvorov discloses wherein the first region (Fig. 1) comprises: an epitaxial layer (22; [0078]: “epitaxial layer”) provided on the substrate (28), and an NCS layer (a collection, See annotated figure) provided on top of the epitaxial layer.
Modifying the cited layer of Kono (24, a generic layer) by forming it using the technique disclosed by Suvorov (i.e., using epitaxy) would arrive at the claimed “epitaxial layer” configuration. A person of ordinary skill in the art would have had a reasonable expectation of success doing so because in each situation the layer is an n-type drift layer (Kono: [0027]: “drift region”; Suvorov: Fig. 1: “N-TYPE DRIFT LAYER”). Suvorov provides a teaching to motivate one of ordinary skill in the art before the effective filing date to have the layer be “an epitaxial layer” in that it would enable an improved doping technique ([0100]: “It is therefore not desirable to amorphize the silicon carbide lattice, as it is difficult for the lattice to be reconstructed”). Therefore, it would have been obvious to have the claimed “epitaxial layer” configuration because it would enable an improved doping technique. MPEP 2143 (I)(G).
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Kono.
Regarding claim12 as noted in the 112(b) rejection, Kono discloses the vertically oriented semiconductor device in accordance with claim 1 (Fig. 7), wherein the second surface layer (40a/40b) has a width (See annotated figure for width markings) that is between 5% - 20% of a lateral spacing (See annotated figure for spacing markings) between the at least two laterally spaced islands.
Kono fails to teach specific width dimensions for the second surface layer, and thus fails to teach “wherein the second surface layer has a width that is between 5% - 20% of a lateral spacing between the at least two laterally spaced islands.” However, the width disclosed by Kono is reasonably close to the claimed width because it is related in the same way to the spacing (i.e., it is less than the spacing. The width is at least greater than 0% and at most less than 100% of the “lateral spacing”. See annotated figure for width and spacing measurement markings). A person of ordinary skill in the art before the effective filing date would have had a reasonable expectation of success including the claimed “width” configuration because: 1) the only difference between Kono and the claims is a recitation of relative dimensions of the claimed device (a width in relation to a spacing), and 2) a device having the claimed relative dimensions would not perform differently than the prior art device (because in each situation the same structures exist in the same arrangement). Therefore, the claimed “second surface layer” configuration is not patentably distinct from the prior art device. MPEP 2144.04 (IV)(A).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to WILLIAM H ANDERSON whose telephone number is (571)272-2534. The examiner can normally be reached Monday-Friday, 8:00-5:00.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Kretelia Graham can be reached at (571) 272-5055. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/WILLIAM H ANDERSON/ Examiner, Art Unit 2817
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