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 .
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.
Claim(s) 1-7 are rejected under 35 U.S.C. 103 as being unpatentable over Wada et al. (2019/0019868) in view of the following comments.
Re claims 1 and 3-6, Wada et al. disclose a silicon carbide substrate (10); and a silicon carbide epitaxial layer (20) on the silicon carbide substrate, wherein the silicon carbide epitaxial layer has a main surface located opposite to an interface between the silicon carbide substrate and the silicon carbide epitaxial layer (Fig. 2 ~ [0070]).
Wada et al. does not specifically disclose an area density of a pit in the main surface is 1/cm2 or less, an area density of a bump in the main surface is less than 0.7/cm2,an area of the pit is 100 µm2 or less and an area of the bump is 100 µm2 or less when viewed in a direction perpendicular to the main surface, and a depth of the pit is 0.01 µm to 0.1 µm and a height of the bump is 0.01 µm to 0.1 µm in the direction perpendicular to the main surface.
Wada et al. disclose the layer thickness ([0070] ~ 15 µm), therefore it can be inferred that the defect densities are reduced to the values claimed in the present invention.
Furthermore, One of ordinary skill in the art would have been led to the recited area density, area, depth and height through routine experimentation to achieve a desired layer associated characteristics and layer imperfection level.
In addition, the selection of area density, area, depth and height, it's obvious because it is a matter of determining optimum process conditions by routine experimentation with a limited number of species of result effective variables. These claims are prima facie obvious without showing that the claimed ranges achieve unexpected results relative to the prior art range. In re Woodruff, 16 USPQ2d 1935, 1937 (Fed. Cir. 1990). See also In re Huang, 40 USPQ2d 1685, 1688 (Fed. Cir. 1996)(claimed ranges or a result effective variable, which do not overlap the prior art ranges, are unpatentable unless they produce a new and unexpected result which is different in kind and not merely in degree from the results of the prior art). See also In re Boesch, 205 USPQ 215 (CCPA) (discovery of optimum value of result effective variable in known process is ordinarily within skill or art) and In re Aller, 105 USPQ 233 (CCPA 1995) (selection of optimum ranges within prior art general conditions is obvious).
Note that the specification contains no disclosure of either the critical nature of the claimed area density, area, depth and height or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen area density, area, depth and height or upon another variable recited in a claim, the Applicant must show that the chosen area density, area, depth and height are critical. In re Woodruf, 919 F.2d 1575, 1578, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990).
Re claim 2, Wada et al. disclose wherein the silicon carbide epitaxial layer (20) has a thickness of 15 µm or more ([0070]).
Re claim 7, Wada et al. disclose preparing the silicon carbide epitaxial substrate (10) according to claim 1; and processing the silicon carbide epitaxial substrate ([0069-0070]).
Citation of Pertinent Prior Art
The following prior art made of record and not relied upon is considered pertinent to applicant's disclosure: US 2018/0096854 A1, US 2016/0197155 A1, 2019/0371894 A1, 9,728,628 B2 and 2014/0054609 A1 disclose a similar configuration for a silicon carbide epitaxial substrate.
Conclusion
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/MICHELLE MANDALA/Primary Examiner, Art Unit 2893 January 20, 2026