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 .
Status of Claims
Claims 1-7, 10-11, 13-14, 17, 19-21, and 23-27 are under consideration in this Office Action.
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the support shiel must be shown or the feature canceled from the claims 4, 13, 24, and 27. No new matter should be entered.
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. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. 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 Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 3-7, 11, 13-14, 17, and 19-21 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention. Drawing as filed do not show the support shield.
Claim Rejections - 35 USC § 103
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 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.
Claims 1-2, 10, 23-26 are rejected under 35 U.S.C. 103 as being unpatentable over Challa et al., US 2008/0138953 (corresponding to US 8,143,124).
In re Claim 1, Challa discloses a semiconductor device 200 (Figs. 2), comprising: a semiconductor layer structure SL (Fig. A) that includes a drift layer 206 having a first n conductivity type; a gate trench 202 that extends to a first depth 1D into the semiconductor layer structure SL ; a gate electrode 210 in the gate trench 202; a support shield trench SST that extends to a second depth 2D into the semiconductor layer structure SL, where the second depth 2D is less than the first depth 1D; and a source metallization layer SML on the semiconductor layer structure SL and extending into the support shield trench SST. (Figs. 1-2 and A; [0109- 0239]).
Challa does not specifically indicate that the semiconductor layer structure SL is a silicon carbide based semiconductor layer structure.
Due to high level of knowledge and skills of personal capable to operate very sophisticated and expensive equipment in semiconductor technology, it would have been an obvious matter of design choice of one of ordinary skill in the semiconductor art to use the silicon carbide based semiconductor layer structure, since 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 (See MPEP2144.07).
PNG
media_image1.png
200
400
media_image1.png
Greyscale
Fig. A. Challa’s Fig. 2A annotated to show the details cited
In re Claim 2, Challa discloses the semiconductor device of Claim 1, wherein the semiconductor layer structure SL further comprises a well contact region 204 having a second p conductivity type underneath the support shield trench SST. (Fig. A).
In re Claim 10, Challa discloses the semiconductor device of Claim 1, wherein the semiconductor layer structure SL further comprises a source region 112, and the source metallization layer directly contacts both an upper surface and a side surface of the source region SML. (Fig. A)
In re Claim 23, Challa discloses a semiconductor device 200 that includes a plurality of unit cell transistors (T1, T2) (Fig. A), comprising: a semiconductor layer structure SL that comprises; a drift layer 206 having a first n conductivity type; a well region 204 having a second p conductivity type on the drift layer 206; a source region 212 having the first n conductivity type on the well region 204; and a well contact region 218 having the second p conductivity type in the well region 204, the well contact region 218 being a portion of the well region 204 that has a higher dopant concentration p+, where an upper surface of the well contact region 218 is recessed below an upper surface of the source region 212; a gate trench 202 that extends to a first depth 1D into an upper surface of the semiconductor layer structure SL; a source metallization layer SML that extends in between source regions 212 of adjacent ones of the unit cell transistors (T1, T2) to directly contact the well contact region 218 (Figs. 1-2 and A; [0109- 0239]).
Challa does not specifically indicate that the semiconductor layer structure SL is a silicon carbide based semiconductor layer structure.
Due to high level of knowledge and skills of personal capable to operate very sophisticated and expensive equipment in semiconductor technology, it would have been an obvious matter of design choice of one of ordinary skill in the semiconductor art to use the silicon carbide based semiconductor layer structure, since 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 (See MPEP2144.07).
In re Claim 24, Challa discloses the semiconductor device of Claim 23, wherein the semiconductor layer structure SL further comprises a support shield (a portion of 204 marked as SSh in Fig. A) having the second p conductivity type underneath the well contact region 218.
In re Claim 25, Challa discloses the semiconductor device of Claim 24, wherein the source metallization layer SML directly contacts the well contact region 218 and the well contact region 218 directly contacts the support shield SSh. (Fig. A)
In re Claim 26, Challa discloses the semiconductor device of Claim 24, wherein the source metallization layer SML directly contacts a side surface of the source region 212 (Fig. A).
Allowable Subject Matter
Claim 27 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.
Reason for indicating allowable subject matter
In re Claim 27: The prior art of record cited by the current office action, alone or in combination, fail to anticipate or render obvious such limitation of claim 27 as: “the well contact region has a first doping concentration of second conductivity type dopants that exceeds a second doping concentration of second p conductivity type dopants of the well region and that also exceeds a third doping concentration of second conductivity type dopants of the support shield”, in combination with limitations of Claims 23 and 24 and 3 on which it depends.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NIKOLAY K YUSHIN whose telephone number is (571)270-7885. The examiner can normally be reached Monday-Friday (7-7 PST).
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, Yara B. Green can be reached at 5712703075. 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.
/NIKOLAY K YUSHIN/Primary Examiner, Art Unit 2893