Ex Parte MASUDA et al

Patent Trials and Appeals BoardJan 9, 2019

13676931 - (D) (P.T.A.B. Jan. 9, 2019)

UNITED STA TES p A TENT AND TRADEMARK OFFICE APPLICATION NO. FILING DATE FIRST NAMED INVENTOR 13/676,931 11/14/2012 Takeyoshi MASUDA 26694 7590 01/11/2019 VENABLELLP P.O. BOX 34385 WASHINGTON, DC 20043-9998 UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www .uspto.gov ATTORNEY DOCKET NO. CONFIRMATION NO. 92396-340455 1087 EXAMINER HSIEH, HSIN YI ART UNIT PAPER NUMBER 2816 NOTIFICATION DATE DELIVERY MODE 01/11/2019 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): PTOMail@Venable.com khauser@venable.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte TAKEYOSHI MASUDA, KEIJI WADA, and TORU HIYOSHI Appeal2018-004424 Application 13/676,931 Technology Center 2800 Before JEFFREY T. SMITH, MICHAEL P. COLAIANNI, and LILAN REN, Administrative Patent Judges. REN, Administrative Patent Judge. DECISION ON APPEAL Appeal2018-004424 Application 13/676,931 STATEMENT OF THE CASE Appellants 1 appeal under 35 U.S.C. Â§ 134 from a rejection2 of claims 1-5 and 7-15. We have jurisdiction under 35 U.S.C. Â§ 6(b). We affirm. CLAIMED SUBJECT MATTER The claims are directed to a method for manufacturing a semiconductor device in a silicon carbide substrate. Claim 1, reproduced below, is illustrative of the claimed subject matter: 1. A method for manufacturing a semiconductor device, comprising the steps of: preparing a substrate made of silicon carbide; forming, in said substrate, a trench opened on one main surface side of said substrate and including a wall surface having an angle of not less than 40Â° and not more than 70Â° with respect to a { 0001} plane; and forming an oxide film in a region including said wall surface of said trench, wherein, in the step of forming said oxide film, said substrate is heated at a temperature of not less than 1250Â°C in an atmosphere containing oxygen, and said trench is formed by performing thermal etching. Claims Appendix (App. Br. 21). 1 The real party in interest is identified as SUMITOMO ELECTRIC INDUSTRIES, LTD. Appeal Brief of June 12, 2017 ("App. Br."), 1. 2 Final Office Action of January 17, 2017 ("Final Act."). In this opinion, we also refer to the Examiner's Answer of January 25, 2018 ("Ans.") and the Reply Brief of March 22, 2017 ("Reply Br."). 2 Appeal2018-004424 Application 13/676,931 REFERENCES The prior art references relied upon by the Examiner in rejecting the claims on appeal are: Amano Nakamura US 6,482,704 Bl US 2007 /0057262 Al REJECTIONS Nov. 19, 2002 Mar. 15, 2007 The Examiner rejects claims 1-5 and 8-15 under pre-AIA 35 U.S.C. Â§ I03(a) as being unpatentable over Amano in view of Nakamura. Final Act. 6. The Examiner rejects claims 11, 13, 14 and, 15 under 35 U.S.C. Â§ 112(a) or 35 U.S.C. Â§ 112 (pre-AIA), first paragraph, as failing to comply with the written description requirement. Final Act. 4. OPINION Obviousness The dispositive issue on appeal with regard to the obviousness rejection is whether Nakamura teaches or suggests a trench that is "formed by performing thermal etching" as recited in claim 1. Appellants argue that the Examiner reversibly erred in finding that plasma etching described in Nakamura teaches or suggests the recited "thermal etching" technique. App. Br. 10. The Examiner explains that based on the dictionary meaning of "thermal," the broadest reasonable interpretation of "thermal etching" is "an etching depending on temperature" which includes plasma etching. Ans. 3. Appellants, on the other hand, argue that thermal etching is an etching technique that "exposes a material to high temperatures to etch the material." App. Br. 3. 3 Appeal2018-004424 Application 13/676,931 Because Appellants' own definition of "thermal etching" does not specify what such high temperatures may be and because Appellants acknowledge that the prior art plasma etching technique may occur at a temperature of 300-500K (App. Br. 10), no reversible error has been identified in the Examiner's finding that Nakamura teaches or suggests the recited limitation. Appellants' argument that a skilled artisan would understand the two etching techniques to be distinct is not supported by evidence in the record. App. Br. 10, 11, and 12; see Johnston v. IVAC Corp., 885 F.2d 1574, 1581 (Fed. Cir. 1989) (attorney argument is no substitute for evidence). We further note that Appellants do not dispute the Examiner's finding that plasma etching is a broader category of etching techniques which necessarily includes thermal etching. Compare Ans. 3, with Reply Br. 2-3. As to Appellants' argument that Nakamura does not teach or suggest plasma etching as an alternative to thermal etching (App. Br. 11 ), we note that Appellants' own reference titled "Shape Control of Trenched 4H-SiC C- F ace by Thermal Chlorine Etching" by Koketsu ("Koketsu") 3 shows that both are known etching techniques in the manufacturing of silicon wafers. Koketsu 051201-1 ("In this paper, thermal Cb etching is applied to the shape control of SiC trenches fabricated by a plasma process."). We accordingly sustain the rejection of claim 1. Appellants do not present arguments separate from those for claim 1 for the obviousness 3 Appellants submit, with the Reply Brief, a reference titled "Shape Control of Trenched 4H-SiC C-Face by Thermal Chlorine Etching" by Koketsu ("Koketsu") in support of the differences between thermal and plasma etching. Reply Br. 7-8. Appellants do not explain why Koketsu could not have been submitted with the opening brief. Id. 4 Appeal2018-004424 Application 13/676,931 rejection of claims 2-5 and 8-15. App. Br. 13. These claims therefore stand or fall with claim 1 for the obviousness rejection. See id.; see also 37 C.F.R. Â§ 4I.37(c)(l)(iv) (2013). Written Description With regard to the written description rejection of claims 11, 13, 14 and 15, the dispositive issue on appeal is whether the specification amendments ( on which Appellants rely for written description support) contain new matter. More specifically, the record shows that the specification was amended at least on March 18, 2015, September 25, 2015, and January 13, 2016. The drawings were amended with the specification amendments on September 25, 2015 and January 13, 2016. Claims 11, 13, 14, and 15 were added as new claims on September 25, 2015. Appellants rely on the amendments to both the specification and drawings on September 25, 2015 and January 13, 2016 for the written description support of these newly added claims. App. Br. 14. Appellants also rely on referential materials 1 and 2 submitted with the September 25, 2015 amendments to show possession. Id. The relevant part of the amendment submitted on September 25, 2015 (as well as the January 13, 2016 amendment) is shown as follows (where the strike through indicates the original phrase to be removed and the underline indicates the new phrase to be added): Here, the film thickness ratio refers to a ratio of the film thickness of the oxide film formed in a region including the bottom side wall surface to the film thickness of the oxide film formed in a region including the side v1all bottom surface. 5 Appeal2018-004424 Application 13/676,931 The relevant tables and drawings were amended likewise to reflect the changes. Appellants argue that the amendments are no more than a clerical error and thus do not constitute new matter. App. Br. 14. "The written description requirement requires possession as shown in the specification, not as shown by prior experimental work." Allergan, Inc. v. Sandoz Inc., 796 F.3d 1293, 1309 (Fed. Cir. 2015). In this case, Appellants acknowledge that the specification only discloses that silicon carbide-not an oxide film- may be grown in the <0001> direction. App. Br. 15 (citing original specification filed November 14, 2012 at 3:29-4:3 and 9:22-23); see also Ans. 4 (finding that the original specification only discloses growing silicon carbide and does not disclose growing the oxide film). Appellants' argument that, despite the lack of disclosure in the original specification, a skilled artisan would understand the oxide film may be grown is unsupported by evidence in the record. App. Br. 15. Such attorneys' argument "is no substitute for evidence." Johnston, 885 F.2d at 15 81. Absent supporting evidence, possession of the subject matter at issue as of the original filing date has not been shown. Appellants purport that referential material 1 is an annotated image of the originally filed Figure 10. App. Br. 14. According to Appellants, referential material 1 emphasizes a showing in Figure 10 that the film thickness of the bottom surface is greater than that of the side wall surface. Id. Both images are reproduced below. 6 Appeal2018-004424 Application 13/676,931 Figure 10 of the original specification showing a film thickness of side wall surface 15A and bottom surface 15B of an oxide film. Spec. 5:22-23, 14:10-11. ~lV\f>.~--~TB,1 ., Side waH surface of trench Referential Material 1. 7 Appeal2018-004424 Application 13/676,931 In describing Figure 10, the original specification provides: "although side wall surface 15A and bottom surface 15B had significantly different plane orientations, oxide film 40 was formed with a film thickness of about 0.05 Âµm on each of side wall surface 15A and bottom surface 15B." Spec. 14: 10-13. Appellants do not adequately explain why their argument and referential material 1 is consistent with the original specification. Moreover, patent drawings are not necessarily intended to show accurate relative dimensions and "arguments based on mere measurement of the drawings [are] of little value." In re Chitayat, 408 F.2d 475,478 (CCPA 1969). We are therefore not persuaded reversible error has been identified based on referential material 1. According to Appellants, referential material 2 ( an excerpt of a Japanese reference accompanied by a partial translation) confirms that the growth rate of a thermal oxide film is the fastest along the { 0001} plane. App. Br. 16. Because the subject matter at issue here is directed to the film thickness - and not the rate in which the film grows - Appellants' argument does not persuaded us that the Examiner reversibly erred in evaluating referential material 2. As a result, the Examiner's written description rejection is sustained. Objections The Examiner objects to the amendments to the specification and drawings on new matter ground. Final Act. 3. Ordinarily an objection is reviewable by petition under 37 C.F .R. Â§ 1.181, while a rejection is appealable. When, however, the issue of new matter presented is the subject of both an objection and a rejection - as is the case at bar, the issue is appealable. Manual of Patent Examining Procedure (MPEP) Â§ 2163 .06, II; 8 Appeal2018-004424 Application 13/676,931 608.04( c) ("[W]here the alleged new matter is introduced into or affects the claims, thus necessitating their rejection on this ground, the question becomes an applicable one, and should not be considered on petition even though that new matter has been introduced into the specification also."). Because both objection turns on the same issues as the written description rejection of the claims, the Board's decision with respect to the written description rejection likewise is dispositive as to the corresponding objections. DECISION The Examiner's decision is affirmed. No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. Â§ 1.136(a). See 37 C.F.R. Â§ 1.136(a)(l )(iv). AFFIRMED 9