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 .
Response to Amendment
The amendment filed 06 May 2026 has been entered.
Claims 14 and 16-26 remain pending in the application, wherein claims 14, 16-17, and 19 have been amended, claims 21-26 are new, and claims 1-13 and 15 are newly canceled.
Support for the amendments are found in paragraph 0023 of the instant specification and in previously presented claim limitations. Accordingly, no new matter has been introduced by these amendments.
Response to Arguments
The amendments have overcome the indefiniteness previously set forth in the Office Action mailed 14 January 2026. However, upon further consideration, new grounds of indefiniteness have been set forth, as outlined below.
Applicant’s arguments, see 6-7, filed 08 April 2026, with respect to the obviousness-type double patenting rejection, have been fully considered and are persuasive in view of the amendments. The nonstatutory double patenting rejection has been withdrawn.
Applicant's arguments, filed 08 April 2026, have been fully considered but they are not persuasive for the following reasons:
Applicant argues, see p. 7-8, that Narita does not disclose that the growth face has an off-angle greater than zero degree relative to the Si-face of the SiC substrate. However, as outlined in the Office Action mailed 14 January 2026 and below, the rejection is based on the teachings of Narita in view of Ota. Narita and Ota both teach a semiconductor device using a SiC substrate with the silicon face as the growth face, and Ota teaches that a SiC substrate having an off angle of 0° to 10° provides high reliability.
Applicant further argues, see p. 8, that the different deposition methods result in different crystal quality and argues this difference as affecting the quality of the upper structure. However, this argument does not objectively show that the difference in deposition method results in an unexpected difference or that it does not result in the instantly claimed FWHM. See MPEP § 2145(I).
Applicant argues, see p. 8, that Narita does not address the technical issue of poor quality caused by substrate angle by utilizing a disordered structure in the nitride angle adjustment layer. However, neither this intended purpose nor the disordered structure are recited features and although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See MPEP § 2145(VI).
Applicant argues, see p. 9, that neither Narita nor Ota provide relevant teachings on how to select the FWHM to block extension of the substrate offset angle when the off-angle is greater than 4 degrees. However, this argument is directed toward how (i.e. a method) to obtain a desired effect (i.e. blocking extension of offset angle to prevent poor quality of the upper structure) whereas the claims are directed to a product (i.e. the method is not relevant to patentability) and Narita teaches a different aspect for preventing poor quality of the upper structure (paragraphs 0006, 0010-0011, 0022-0026). This argument also lacks objective evidence that the semiconductor device of Ota-modified Narita does not have the instantly claimed FWHM properties, and the courts have held that prima facie obviousness is not rebutted by merely recognizing additional advantages or latent properties present but not recognized in the prior art. See MPEP § 2145(II).
Claim Objections
Claim 19 is objected to because of the following informalities: Claim 19 recites “a root mean square (RMS roughness)”. The term “roughness” should be outside of the parentheses since RMS is known in the art as an abbreviation for root mean square but not RMS roughness. It is suggested to present the term as “root mean square (RMS) roughness”.
Appropriate correction is required.
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.
Claims 14 and 16-20 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Regarding claim 14: A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 14 recites the broad recitation of an off-angle greater than zero degrees, and the claim also recites the off-angle is greater than 4 degrees, which is a narrower statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
Regarding claim 16: A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 16 recites the broad recitation of an off-angle greater than zero degrees, and the claim also recites off-angle is greater than or equal to 1 degree and less than or equal to 4 degrees, which is the narrower statement of the range/limitation. Furthermore, claim 16 recites a thickness of the nitride angle adjustment layer is less than 50 nm and also recites this thickness as less than 25 nm. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
Regarding claim 17: A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 17 recites the broad recitation of an off-angle greater than zero degrees (i.e. an open ended range), and the claim also recites the off-angle is less than 1 degree (i.e. recited as a separate limitation, also open ended, instead of being linked with the range of greater than zero degrees), which is a narrower statement of the range/limitation. Furthermore, claim 17 recites a thickness of the nitride angle adjustment layer is less than 50 nm and also recites this thickness as less than 10 nm. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
Claims 18-26 each recite the method as claimed (in a previous claim). However, the claims on which these claims depend are directed to an epitaxial structure, not a method. In the interest of advancing prosecution, the disputed limitation will be considered to refer to the epitaxial structure of the independent claims.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 14 and 16-20 are rejected under 35 U.S.C. 103 as being unpatentable over Narita et al. (JP 2013211442A, previously cited) in view of Ota et al. (US 2016/0268381, previously cited).
Claim 14: Narita teaches a nitride semiconductor epitaxial wafer (i.e. an epitaxial structure) formed with a silicon carbide (SiC) substrate (paragraph 0001). The SiC substrate is an on-axis in the <0001> direction and a Si surface is used (i.e. a silicon face of the SiC substrate is taken as a growth face) (paragraph 0044). An AlN buffer layer is formed on the substrate made of silicon carbide, and a nitride semiconductor crystal is formed on the buffer layer (paragraph 0015). Before forming the AlN buffer layer, a metal layer made of an Al film (from a metal source material containing Al such as TMA; paragraph 0029) is formed on the SiC substrate and then heat treatment is performed in an atmosphere containing ammonia so that the lattice constant of the AlN buffer layer can be controlled (paragraph 0026), such that a layer of fine crystal nuclei of AlN (i.e. a nitride angle adjustment layer located on the growth face of the SiC substrate) is formed (paragraph 0029) and there is no bias in the distribution of Al when crystallized because the Al atoms are likely to move around and form an in-plane uniform layer of Al (paragraph 0032). The average particle diameter of the fine crystal nucleus is set to 8 nm or more and 13.5 nm or less (paragraph 0039) (i.e. a minimum layer thickness of the fine crystal nucleus is the average particle diameter because the layer thickness is not less than one layer of fine crystal nucleus particles), which overlaps the instantly claimed thickness. The courts have held that a prima facie case of obviousness exists where claimed ranges overlap, lie inside of, or are close to ranges in the prior art. See MPEP § 2144.05. It is noted that as of the writing of this Office Action, no demonstration of a criticality to the claimed ranges has been presented. After forming the fine crystal nuclei (i.e. the nitride angle adjustment layer), TMA (i.e. aluminum source) and NH3 (i.e. ammonia) were simultaneously supplied to grow an AlN buffer layer (i.e. a first group III nitride layer located on the nitride angle adjustment layer) (paragraph 0029). A GaN layer (i.e. a second group III nitride layer) is grown on the AlN buffer layer (i.e. on the first group III nitride layer) (paragraphs 0036 and 0050). However, Narita does not teach the instantly claimed off-angle.
In a related field of endeavor, Ota teaches a semiconductor substrate of SiC including a surface inclined from a {0001} face (also including a (0001) face; paragraph 0016) at an off angle of 0° to 10° (paragraph 0013). This off angle overlaps the instantly claimed range. See MPEP § 2144.05. The (0001) face, also indicated as the silicon face, is shown as the growth face (Figs. 1-2). This semiconductor substrate has low area density of the TED clusters and it is possible to suppress the variation of the forward ON voltage and provides high reliability (paragraph 0038).
As Narita and Ota both teach a semiconductor device using a SiC substrate with the silicon face as the growth face, they are analogous. It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the nitride semiconductor epitaxial wafer of Narita to include where the SiC substrate at an off angle of 0° to 10° from the (0001) face as taught by Ota as such substrate can provide high reliability, and one would have had a reasonable expectation of success. Narita does not particularly teach the layer of fine crystal nuclei to be formed by PVD, but this limitation is considered to be a product-by-process limitation which is not limited to the manipulations of the recited steps. See MPEP § 2113.
Regarding the instantly claimed FWHM, Narita teaches a layer of fine crystal nuclei of AlN (i.e. a nitride angle adjustment layer located on the growth face of the SiC substrate) is formed (paragraph 0029) and that there is no bias in the distribution of Al when crystallized because the Al atoms are likely to move around and form an in-plane uniform layer of Al (paragraph 0032) and that the layer (i.e. of fine crystal nuclei) changes the lattice constant of the AlN buffer layer (paragraph 0026) to avoid being distorted which affects generation of surface pits (paragraph 0024). This disclosure by Narita compares to the instant disclosure of a nitride angle adjustment layer made of AlN that automatically performs an angle adjustment process and therefore improves epitaxial quality of the first group III nitride layer and the second group II nitride layer (paragraph 0028 of the instant specification). As such, the instantly claimed FWHM is considered to be present because substantially identical materials have substantially identical properties. See MPEP § 2112.01.
Claim 16: The limitations of instant claim 16 are substantially identical to those of instant claim 14 (outlined above) except to recite different ranges for the off-angle, thickness of the nitride angle adjustment layer, and FWHM. Ota teaches the off angle is 0° to 10°, which overlaps the instantly claimed range. See MPEP § 2144.05. Narita teaches a layer of fine crystal nuclei of AlN (i.e. a nitride angle adjustment layer located on the growth face of the SiC substrate) is formed (paragraph 0029), and the average particle diameter of the fine crystal nucleus is set to 8 nm or more and 13.5 nm or less (paragraph 0039) (i.e. a minimum layer thickness of the fine crystal nucleus is the average particle diameter because the layer thickness is not less than one layer of fine crystal nucleus particles), which overlaps the instantly claimed thickness. See MPEP § 2144.05. The instantly claimed FWHM is considered to be present for the same reasons outlined above regarding FWHM of instant claim 15.
Claim 17: The limitations of instant claim 17 are substantially identical to those of instant claim 14 (outlined above) except to recite different ranges for the off-angle, thickness of the nitride angle adjustment layer, and FWHM. Ota teaches the off angle is 0° to 10°, which overlaps the instantly claimed range. See MPEP § 2144.05. Narita teaches a layer of fine crystal nuclei of AlN (i.e. a nitride angle adjustment layer located on the growth face of the SiC substrate) is formed (paragraph 0029), and the average particle diameter of the fine crystal nucleus is set to 8 nm or more and 13.5 nm or less (paragraph 0039) (i.e. a minimum layer thickness of the fine crystal nucleus is the average particle diameter because the layer thickness is not less than one layer of fine crystal nucleus particles), which overlaps the instantly claimed thickness. See MPEP § 2144.05. The instantly claimed FWHM is considered to be present for the same reasons outlined above regarding FWHM of instant claim 15.
Claims 18, 21, and 24: Narita teaches that after forming the fine crystal nuclei of AlN (i.e. the nitride angle adjustment layer), TMA (i.e. aluminum source) and NH3 (i.e. ammonia) were simultaneously supplied to grow an AlN buffer layer (i.e. the first group III nitride layer located on the nitride angle adjustment layer) (paragraph 0029). A GaN layer (i.e. the second group III nitride layer) is grown on the AlN buffer layer (i.e. on the first group III nitride layer) (paragraphs 0036 and 0050). These layers can be formed by metal organic chemical vapor deposition (paragraphs 0005 and 0059).
Claims 19-20, 22-23, and 25-26: Narita teaches a GaN layer (i.e. the second group III nitride layer) is grown on the AlN buffer layer (i.e. on the first group III nitride layer) (paragraphs 0036 and 0050). Narita does not specifically teach a root mean square roughness (see indefiniteness outlined above) or FWHM, but does teach that the nitride semiconductor epitaxial wafer (i.e. including the GaN layer) is manufactured by the MOVPE (i.e. metal organic chemical vapor deposition; paragraph 0005) apparatus (i.e. by epitaxial growth) (paragraph 0059) and no pits were observed (paragraphs 0051, 0053, and 0055), presumably due to lack of lattice distortion of the AlN buffer layer (paragraph 0024) and in-plane uniform layer of Al that forms the fine crystal nuclei (paragraph 0032). These teachings support a conclusion of the GaN layer being substantially defect-free and substantially uniform. Furthermore, the GaN layer is considered to have a substantially identical RMS roughness and FWHM because substantially identical materials have substantially identical properties. See MPEP § 2112.01.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KIM S HORGER whose telephone number is (571)270-5904. The examiner can normally be reached M-F 9:30 AM - 4:00 PM EST.
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/KIM S. HORGER/Examiner, Art Unit 1784
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