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 .
Election/Restrictions
Applicant’s election without traverse of Group I in the reply filed on 10/24/2025 is acknowledged.
Claims 9-19 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 10/24/2025.
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 4-5 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.
Re claim 4, the phase “the electron concentration of the n-GaN region” lacks antecedent basis.
Re claim 4, the phrase “the electron concentration of the n−-GaN drift layer” lacks antecedent basis.
Re claim 5, the phase “the electron concentration of the n-GaN region” lacks antecedent basis.
Re claim 5, the phrase “the electron concentration of the n−-GaN drift layer” lacks antecedent basis.
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.
(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 are rejected under 35 U.S.C. 102(a)(1) as being anticiapted by Shimizu et al., US Pat. No. 11,296,220 B2.
Re claim 1. Shimizu et al. disclose a GaN trench MOSFET fabricated on an n-GaN substrate 20 (e.g., fig. 1) comprising (a) a drift layer of n--GaN 22 (e.g., fig. 1) sharing an interface with the n-GaN substrate 20, (b) a p-type Mg-doped GaN layer 26a, 26b, 28a and/or 28b (e.g., fig. 1) sharing an interface with the drift layer 22; (c) a trench 32 (e.g., fig. 1) having an angled surface of p-type Mg-doped GaN, (d) an n-GaN region 24 (e.g., fig. 1) below a bottom of the trench 32, (e) an n-GaN source 30a/b (e.g., fig. 1) above the Mg-doped GaN layer 26a, 26b, 28a and/or 28b (e.g., fig. 1) and outside of the trench 32, wherein the n-GaN region 24 contains both Mg and a donor impurity (e.g., fig. 1 & fig. 4, col. 8, line 61 to col. 9, line 7; n-GaN region 24 is formed by implantation of a donor impurity, Si, in the Mg-doped GaN layer 26a, 26b, 28a and/or 28b). See figs. 1-12 and cols. 1-24 for more details.
Re claim 2. The GaN trench MOSFET of claim 1, wherein the n-GaN region 24 extends from the bottom of the trench 32 to the drift layer 22 (e.g., fig. 1).
Re claim 3. The GaN trench MOSFET of claim 1, wherein the n-GaN region 24 extends laterally beneath the trench 32 and from the trench bottom so that the interface between the drift layer 22 and the p-type Mg-doped GaN layer 26a/b is closer to the substrate 20 than an interface between the n-GaN region 24 and the p-type Mg-doped GaN layer 28b (e.g., fig. 1).
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 4-8 are rejected under 35 U.S.C. 103 as being unpatentable over Shimizu et al., US Pat. No. 11,296,220 B2.
Shimizu et al. teach above; although the exact recitations “the electron concentration of the n-GaN region is within +/−50% difference of the electron concentration of the n−-GaN drift layer” of instant claims 4-5 and “crystallographic plane selected from (101), (201), or (102) plane” of instant claim 6 and “crystallographic plane individually selected from (101), (201), or (102) plane” of instant claim 7 are not explicitly stated by Shimizu et al. in the related text, it appears that the instant recited concentration range and selected crystallographic plane is within the cited prior art’s concentration range (e.g., col. 5, lines 4-9, concentration of 24 is higher than 22; i.e., within 50%) and the angle surface crystallographic plane (e.g., having the similar trench’s surface structure/orientation); therefore, claims 4-5 and 6-7 appear to be Prima Facie obvious Shimizu et al.
The concentration range of claims 4-5 and the specific crystallographic plane of instant claims 6-7 are considered to involve routine optimization while has been held to be within the level of ordinary skill in the art. As noted in In re Aller, the selection of reaction parameters such as temperature and concentration etc. would have been obvious:
“Normally, it is to be expected that a change in temperature, or in concentration, or in both, would be an unpatentable modification. Under some circumstances, however, changes such as these may impart patentability to a process if the particular ranges claimed produce a new and unexpected result which is different in kind and not merely degree from the results of the prior art...such ranges are termed Acritical ranges and the applicant has the burden of proving such criticality.... More particularly, where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.”
In re Aller 105 USPQ233, 255 (CCPA 1955). See also In re Waite 77 USPQ 586 (CCPA 1948); In re Scherl 70 USPQ 204 (CCPA 1946); In re Irmscher 66 USPQ 314 (CCPA 1945); In re Norman 66 USPQ 308 (CCPA 1945); In re Swenson 56 USPQ 372 (CCPA 1942); In re Sola 25 USPQ 433 (CCPA 1935); In re Dreyfus 24 USPQ 52 (CCPA 1934).
Therefore, one of ordinary skill in the requisite art before the invention was made would have used any concentration range and crystallographic plane suitable to the device of Shimizu et al. in order to optimize the performance of the device.
Re claim 8, Shimizu et al. teaches a GaN trench MOSFET having the similar trench structure/shape (e.g., fig. 1) as fig. 3 of the instant application. In addition, using the hexagonally shaped trench has been well-known in the semiconductor art. The selection of a known shape based on its suitability for its intended use supported a prima facie obviousness determination in In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966) (The court held that the configuration of the claimed container was a matter of choice which a person of ordinary skill in the art would have found obvious absent persuasive evidence that the particular configuration of the claimed container was significant.)
Furthermore, the specification contains no disclosure of either the critical nature of the claimed arrangement (i.e. - the electron concentration of the n-GaN region is within +/−50% difference of the electron concentration of the n−-GaN drift layer and/or crystallographic plane selected from (101), (201), or (102) plane or the trench is hexagonally shaped) or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen limitations or upon another variable recited in a claim, the Applicant must show that the chosen limitations are critical. In re Woodruff, 919 F.2d 1575, 1578 (Fed. Cir. 1990).
Conclusion
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/JACK S CHEN/Primary Examiner, Art Unit 2893