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 § 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 14,30 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 14, it is not clear how the acceptor impurity is practically not contained in the extension portion while the main portion has the impurity.
Claim 30 imposes conditions and variable that are not clear, for example the condition: “if a region up to X nm upward from a lower surface of the third nitride semiconductor layer is a lower layer portion,” is not clear.
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.
Claim(s) 1,3-11,13,15-20,22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kanda et al., (Kanda) US 2007/0254419 in view of Ueda et al., (Ueda) US 2009/0121775.
Regarding claim 1, Kanda discloses and shows in FIG. 12A, a nitride semiconductor device comprising: a first nitride semiconductor layer (13)[0154] that constitutes an electron transit layer; a second nitride semiconductor layer (14)[0154] that is formed above the first nitride semiconductor layer (13), is greater in bandgap than the first nitride semiconductor layer (13)[0156], and constitutes an electron supply layer; a third nitride semiconductor layer (23)[0154] that is formed selectively above the second nitride semiconductor layer (14), includes a ridge portion of a ridge shape, and contains an acceptor type impurity; a gate electrode (15)[0154] that is formed above the ridge portion; wherein the third nitride semiconductor layer (23) has an extension portion that extends outward from a portion below a thickness intermediate position of at least one side surface of the ridge portion (extended portion of layer 23).
Kanda differs from the claimed invention because he does not explicitly disclose a device having a passivation film that is disposed on the second nitride semiconductor layer, the third nitride semiconductor layer, and the gate electrode and has a first opening portion and a second opening portion that are disposed across the ridge portion from each other; a source electrode that is in contact with the second nitride semiconductor layer via the first opening portion and with which a portion is formed above the passivation film; and a drain electrode that is in contact with the second nitride semiconductor layer via the second opening portion and with which a portion is formed above the passivation film such as to oppose the source electrode across the ridge portion.
Ueda discloses a device having a passivation film (107)[0055] that is disposed on the second nitride semiconductor layer (104)[0055], the third nitride semiconductor layer (105), and the gate electrode (110) and has a first opening portion and a second opening portion [0055] that are disposed across the ridge portion from each other; a source electrode (108)[0055] that is in contact with the second nitride semiconductor layer (104) via the first opening portion and with which a portion is formed above the passivation film; and a drain electrode (109) that is in contact with the second nitride semiconductor layer (104) via the second opening portion and with which a portion is formed above the passivation film (107) such as to oppose the source electrode (108) across the ridge portion.
Ueda is evidence that ordinary workers skilled in the art would find reasons, suggestions or motivations to modify the device of Kanda. Therefore, at the time the invention was made; It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the teaching of Ueda in the device of Kanda because it will suppress the occurrence of leakage current [0011].
Regarding claim 3, Kanda in view of Ueda discloses a nitride semiconductor device, wherein the extension portion (extension of 23) includes a first extension portion that extends toward the first opening portion (Kanda modified by Ueda) from a side surface of the ridge portion at the first opening portion side (opening shown in Ueda).
Ueda is evidence that ordinary workers skilled in the art would find reasons, suggestions or motivations to modify the device of Kanda. Therefore, at the time the invention was made; It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the teaching of Ueda in the device of Kanda because it will suppress the occurrence of leakage current [0011].
Regarding claim 4, Kanda in view of Ueda discloses a nitride semiconductor device, wherein the extension portion (extension of 23) (see Kanda) includes a second extension portion that extends toward the second opening portion (opening shown in Ueda) from a side surface of the ridge portion at the second opening portion side.
Ueda is evidence that ordinary workers skilled in the art would find reasons, suggestions or motivations to modify the device of Kanda. Therefore, at the time the invention was made; It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the teaching of Ueda in the device of Kanda because it will suppress the occurrence of leakage current [0011].
Regarding claim 5, Kanda in view of Ueda discloses a nitride semiconductor device, wherein the extension portion (23) includes a first extension (extended portion of 23) portion that extends toward the first opening portion from a side surface of the ridge portion at the first opening portion side (shown in Ueda) and a second extension portion (portion 23) that extends toward the second opening portion from a side surface of the ridge portion at the second opening portion side.
Ueda is evidence that ordinary workers skilled in the art would find reasons, suggestions or motivations to modify the device of Kanda. Therefore, at the time the invention was made; It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the teaching of Ueda in the device of Kanda because it will suppress the occurrence of leakage current [0011].
Regarding claim 6, Kanda in view of Ueda discloses a nitride semiconductor device, wherein the third nitride semiconductor layer (23) includes a pair of the ridge portions that are disposed opposite each other across the first opening portion (opening in Ueda) and a coupling portion that couples corresponding end portions of the pair of ridge portions (extended portion of 23) to each other and the extension portion includes, in a nonactive region, a nonactive extension portion that extends outward from a portion below a thickness intermediate position of a side surface of the pair of ridge portions (23) or the coupling portion.
Ueda is evidence that ordinary workers skilled in the art would find reasons, suggestions or motivations to modify the device of Kanda. Therefore, at the time the invention was made; It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the teaching of Ueda in the device of Kanda because it will suppress the occurrence of leakage current [0011].
Regarding claims 7-10, Kanda in view of Ueda disclose [0154] a device wherein a length of the first extension portion is not less than 0.3 times and not more than 0.9 times a width of the ridge portion; wherein a length of the second extension portion is not less than 0.7 times and not more than 2.0 times a width of the ridge portion; wherein a length of the second extension portion is not less than 0.7 times and not more than 1.5 times a width of the ridge portion; wherein a length of the first extension portion is not less than 0.3 times and not more than 0.9 times a width of the ridge portion and a length of the second extension portion is not less than 0.7 times and not more than 2.0 times the width of the ridge portion.
Applicant did not show criticality of the particular value of the extension portion, the length of the extended portion. To establish unexpected results over a claimed range or optimum value, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960).
Regarding claim 11, Kanda in view of Ueda discloses a nitride semiconductor device wherein lengths, in a width direction of a cross section of the ridge portion (23), of the first extension portion and the second extension portion differ from each other (the design fabrication of 23 will not be uniform for the ridge).
Regarding claim 13, Kanda in view of Ueda discloses a semiconductor device, wherein an average concentration of the acceptor type impurity in the extension portion (23) is lower than an average concentration of the acceptor type impurity in the ridge portion.
Regarding claims 15-19, Kanda in view of Ueda discloses a nitride semiconductor device wherein a film thickness of the extension portion is not more than 25 nm; wherein a film thickness of the extension portion is not more than 15 nm; wherein a film thickness of the extension portion is not less than 3 nm; wherein a film thickness of the extension portion is not more than ⅕ of a film thickness of the ridge portion; wherein a film thickness of the extension portion is not more than 1/7 of a film thickness of the ridge portion [0154].
Applicant did not show criticality of the particular value of the film thickness. To establish unexpected results over a claimed range or optimum value, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960).
Regarding claim 20, Kanda in view of Ueda discloses a nitride semiconductor device, wherein the first extension portion (of 23) [0154] or the second extension portion has a first tapered portion at a junction portion with the ridge portion and a taper angle of the first tapered portion with respect to a front surface of the second nitride semiconductor layer is not more than 45 degrees (see 23).
Regarding claim 22, Kanda in view of Ueda disclose a nitride semiconductor device, wherein the first extension portion or the second extension portion (extension of 23) has a thick film portion that extends outward from a region below a thickness intermediate portion of a side surface of the ridge portion and a thin film portion that extends outward from a region below a thickness intermediate portion of a side surface of the thick film portion (see 23)[0154].
Claim(s) 2,29 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kanda in view of Ueda as applied to claims 1,3-11,13,15-20,22, and further in view of Otake et al., (Otake) US 2020/0176595
Regarding claims 2,29, Kanda in view of Ueda discloses a nitride semiconductor device wherein the first nitride semiconductor layer (13) is constituted of a GaN layer, the second nitride semiconductor layer (14) is constituted of an Al.sub.xGa.sub.(1-x)N (0.1>x>0.3) layer [0154].
Kanda in view of Ueda differs from the claimed invention because he does not explicitly disclose a device wherein the source electrode is formed above the passivation film such as to cover a portion of the gate electrode, the second opening portion side end of the source electrode is positioned between the ridge portion and the second opening portion in plan view, and the third nitride semiconductor layer has, between the ridge portion side end of the first opening portion and the second opening portion end of the source electrode, the extension portion that extends outward from the portion below the thickness intermediate position of at least one side surface of the ridge portion; the third nitride semiconductor layer is constituted of a p type GaN layer, and the acceptor type impurity is constituted of Mg or Zn.
Otake a device wherein the source electrode (9)[0049] is formed above the passivation film (6)[0049] such as to cover a portion of the gate electrode (23), the second opening (in 6) portion side end of the source electrode (9) is positioned between the ridge portion and the second opening portion in plan view, and the third nitride (21)[0059] semiconductor layer has, between the ridge portion side end of the first opening portion and the second opening portion end of the source electrode (9), the extension portion that extends outward from the portion below the thickness intermediate position of at least one side surface of the ridge portion; the third nitride (21) semiconductor layer is constituted of a p type GaN layer (21)[0057], and the acceptor type impurity is constituted of Mg or Zn [0057].
Otake is evidence that ordinary workers skilled in the art would find reasons, suggestions or motivations to modify the device of Kanda in view of Ueda. Therefore, at the time the invention was made; It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the teaching of Otake in the device of Kanda in view of Ueda because a nitride semiconductor device capable of reducing a gate leakage current [0009].
Allowable Subject Matter
Claims 12,21,23-28,31-35 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.
Claims 36-39 allowed.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MARC-ANTHONY ARMAND whose telephone number is (571)272-5178. The examiner can normally be reached 8am-5pm.
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MARC - ANTHONY ARMAND
Examiner
Art Unit 2813
/MARC-ANTHONY ARMAND/ Examiner, Art Unit 2813
/SUE A PURVIS/Supervisory Patent Examiner, Art Unit 2893