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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Election/Restrictions
Applicant’s election without traverse of claims 1-7, 13-15, 18, and 21-22 in the reply filed on July 23, 2026 is acknowledged.
Claim Objections
Claims 1-7 and 13-15 are objected to because of the following informalities:
Claim 1, line 2: Change the period after “conductivity” to a comma.
Claims 2-7 and 13-15 are objected to for depending from objected-to claim 1.
Claim 7, line 4: Please provide antecedent basis for “said power electronic device”.
Claim 13, line 3: Change “a” before “semiconductor body” top “the”. The semiconductor body is defined in claim 1.
Claim 15, line 1: Please provide antecedent basis for “said power electronic device”.
Appropriate correction is required.
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 7, 13, 15, 21, and 22 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.
Regarding claim 7, which depends from claim 6, which depends from claim 1: Claim 7 refers to “said power electronic device”. However, the power electronic device has not been defined in claim 1, claim 6, or claim 7. Because the term is not defined, claim 7 is rejected as indefinite.
Regarding claim 13, which depends from claim 1: Claim 13, line 3, defines “a semiconductor body”. However, claim 1, from which claim 13 depends, defines “a semiconductor body” in line 2. Because a semiconductor body has already been defined in claim 1, another definition of “a semiconductor body” in claim 13 raises a question as to whether the claim 13 semiconductor body is the same as the claim 1 semiconductor body, or different. Because the language is unclear, claim 13 is rejected as indefinite.
Regarding claim 15, which depends from claim 1: Claim 15 refers to “said power electronic device”. However, the power electronic device has not been defined in claim 1 or claim 15. Because the term is not defined, claim 15 is rejected as indefinite.
Regarding claim 21: This claim requires in the last line the following: “forming source regions within the body regions.” This raises a question as to whether one source region is formed in each body region, or multiple source regions are formed in each body region. Because the language is unclear, claim 21 is rejected as indefinite.
Claim 22 is rejected for depending from rejected base claim 21.
Claim Rejections - 35 USC § 102
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.
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.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1-3 and 13 are rejected under 35 U.S.C. 102(a)(1)/(a)(2) as being anticipated by Zhang, U.S. Pat. No. 9,929,284, Figures 3A, 3B, 5A-5F, and 6.
PNG
media_image1.png
733
391
media_image1.png
Greyscale
PNG
media_image2.png
908
447
media_image2.png
Greyscale
PNG
media_image3.png
244
425
media_image3.png
Greyscale
Regarding claim 1: Zhang Figures 3A, 3B, 5A-5F, and 6 disclose a method, comprising: forming a semiconductor body (130) of silicon carbide having a first electrical conductivity (n), a first doping value, and defining a front surface; forming a current spreading layer (160) at a surface portion of the semiconductor body (130) facing the front surface, the current spreading layer (160) having the first electrical conductivity (n) and a second doping value that is greater than the first doping value; and forming elementary cells in an active area of the semiconductor body (130) at the front surface, and wherein forming the current spreading layer (160) includes performing a channeled ion implantation, in a channeling condition, for implanting doping ions having the first electrical conductivity (n) within the semiconductor body (130). Zhang specification, col. 7, l. 40 – col. 10, l. 61; col. 12, l. 14 – col. 15, l. 10.
Regarding claim 2, which depends from claim 1: Zhang discloses wherein the doping ions are phosphorus atoms. See id. col. 8, ll. 6-9, 52-63.
Regarding claim 3, which depends from claim 1: Zhang discloses wherein said channeled ion implantation is performed along an implantation direction tilted by a non-zero tilt angle with respect to said front surface. Id. col. 12, ll. 14-53.
Regarding claim 13, which depends from claim 1: Zhang discloses providing a wafer comprising a substrate (120); and wherein forming a semiconductor body (130) comprises performing an epitaxial growth above said substrate (120) to form said semiconductor body (130). Id. col. 7, ll. 54-63; col. 8, ll. 4-19.
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 4 is rejected under 35 U.S.C. 103 as being unpatentable over Zhang, and further in view of Okumura, U.S. Pat. Pub. No. 2018/0350976, Figures 1A-19.
Regarding claim 4, which depends from claim 3: Zhang is silent as to the tilt angle for the channeled ion implantation.
Okumura, directed to similar subject matter, discloses a channeled ion implantation wherein said tilt angle is comprised between 3.5° and 4.5°, such that said channeled ion implantation is directed along a main axis of the silicon carbide crystallographic lattice of said semiconductor body and the doping ions penetrate within said semiconductor body. Okumura specification ¶¶ 44-78. One having ordinary skill in the art at a time before the effective filing date would be motivated to modify Zhang to include the Okumura technique because the Okumura technique is suitable for implanting ions using channeled ion implantation in SiC semiconductor bodies.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Zhang.
Regarding claim 5, which depends from claim 1: Zhang does not specifically disclose that said channeled ion implantation has a substantially flat implant profile along a vertical axis orthogonal to said front surface in a depth direction of said current spreading layer (160). However, given that the same technique is used as that claimed, said channeled ion implantation would be expected to have a substantially flat implant profile along a vertical axis orthogonal to said front surface in a depth direction of said current spreading layer.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Zhang, and further in view of Okumura, and Rupp, U.S. Pat. Pub. No. 2019/0296141.
Regarding claim 14, which depends from claim 1: Zhang discloses that the semiconductor body is SiC, but is silent as to further details.
Okumura, directed to similar subject matter, discloses said semiconductor body (2) is of 4H-SiC with an off-cut angle of 4°. Okumura specification ¶ 65. One having ordinary skill in the art at a time before the effective filing date would be motivated to modify Zhang to include the Okumura material because the modification would have involved a selection of a known material based on its suitability for its intended use.
Rupp, directed to similar subject matter, discloses the semiconductor body is a 4H-SiC polytype. Rupp specification ¶ 120. One having ordinary skill in the art at a time before the effective filing date would be motivated to modify Zhang to use the polytype because the modification would have involved a selection of a known material based on its suitability for its intended use.
Allowable Subject Matter
Claim 18 is allowed, with claims 19 and 20 being allowable once rejoined.
Claims 21 and 22 would be allowable if rewritten or amended to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action.
Claims 6, 7, and 15 are 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, and in the case of claims 7 and 15, if the informalities and Section 112(b) rejections were addressed.
The following is a statement of reasons for the indication of allowable subject matter:
With regard to claim 6: The claim has been found allowable because the prior art of record does not disclose “wherein said current spreading layer is continuous and seamless in said active area”, in combination with the remaining limitations of the claim.
With regard to claim 7: The claim has been found allowable due to its dependency from claim 6 above.
With regard to claim 15: The claim has been found allowable because the prior art of record does not disclose “said power electronic device is a MOSFET transistor”, in combination with the remaining limitations of the claim.
With regard to claim 18: The claim has been found allowable because the prior art of record does not disclose “forming a first body region and a second body region in the semiconductor body, the first and second body regions having a second depth in the direction less than the first depth, and the first body region is spaced apart from the second body region; forming a first source region within the first body region; forming a second source region within the second body region; forming a body contact region extending through the second source region to the second body region; forming a gate insulating region on the current spreading layer and on the first and second body regions; forming a gate conductive region on the gate insulating region; forming a passivation region covering the gate conductive region; and forming a metallization region covering the passivation region, and wherein forming the current spreading layer includes performing a channeled ion implantation, in a channeling condition, for implanting doping ions having the first electrical conductivity within the semiconductor body”, in combination with the remaining limitations of the claim.
With regard to claims 19 and 20: The claims have been found allowable due to their dependency from claim 18 above.
With regard to claim 21: The claim has been found allowable because the prior art of record does not disclose “the current spreading layer being continuous and seamless in the active area; forming body regions within the current spreading layer at the front surface, the body regions having a depth less than a depth of the current spreading layer, the body regions being separated from each other in a direction parallel to the front surface by intercell regions; and forming [a] source region[] within [each of] the body regions”, in combination with the remaining limitations of the claim.
With regard to claim 22: The claim has been found allowable due to its dependency from claim 21 above.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VICTORIA KATHLEEN HALL whose telephone number is (571)270-7567. The examiner can normally be reached Monday-Friday, 8 a.m.-5 p.m.
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, Fernando Toledo can be reached at 571-272-1867. 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.
/Victoria K. Hall/Primary Examiner, Art Unit 2897
Prosecution Insights