DETAILED ACTION
This Office Action is in response to Application filed June 2, 2023.
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
Applicants' election with traverse of Group I, claims 1-9, in the reply filed on December 9, 2025 is acknowledged. The traversal is on the grounds that “Applicant respectfully submits that a thorough search and examination of the claims in Group I (Claims 1-9) would be relevant to the examination of the claims of Group II (Claim 10) and Group III (Claims 11-14), and would not be a serious burden on the Examiner”, that “Accordingly, Group I, Group II, and Group III relate to a single general inventive concept”, and that “Further, relative to Wang, which is cited by the Office, Applicant submits that Wang fails to teach or suggest at least the following technical features "the second buffer layer is doped with iron impurities, and wherein the first buffer layer and the third buffer layer are not actively doped with iron impurities." as recited in Claims 1, 10, and 11”.” This is not found persuasive because (a) a serious burden on the Examiner for search and examination, while it may be a standard for a restriction of species in a US filed application, is not a standard for restriction of distinct inventions in a 371 application, (b) Applicants do not provide any evidence that there would not be any serious burden for search and examination when the Examiner performs search and examination of claims directed to distinct inventions, (c) it is not clear how the non-serious burden is exactly correlated with a single general inventive concept as Applicants allege, and (d) the last argument cited above is not persuasive since, as discussed below under 35 USC 112(b) rejection and prior art rejections, Applicants’ underlined limitation of claim 1 cited above is indefinite and thus Wang et al. would read on claim 1. The requirement is still deemed proper and is therefore made FINAL.
Drawings
The drawings are objected to because there is no indication what or which layer(s) the numeral 33 corresponds to in Fig. 1 of current application. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Specification
The disclosure is objected to because of the following informalities: Applicants do not explain what the layer(s) that correspond(s) to the numeral 33 shown in Fig. 1 of current application refer(s) to, what it is or they are formed of and/or what it does or they do. 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.
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 1-9 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 1, it is not clear what the limitation “the first buffer layer and the third buffer layer are not actively doped with iron impurities (emphasis added)” recited on line 10 suggests, because (a) the claimed invention is directed to “An epitaxial structure of a semiconductor device” rather than a method of forming an epitaxial structure of a semiconductor device, (b) it is not clear whether the phrase “not actively doped” suggests “undoped”, “passively doped” or “unintentionally doped”, (c) it is not clear whether the phrase “not actively doped” is directed to Applicants’ intention or design, but the actual concentration of iron impurities included in the first and third buffer layer in the final structure of the claimed epitaxial structure was not measured or is unknown, (d) depending on how the phrase “not actively doped” is interpreted, the first and third buffer layer may or may not be doped with iron impurities, and the concentration of the iron impurities included in the first and third buffer layer would also vary, (e) for example, as Fig. 4 of Ishiguro et al. (US 10,431,656) shows, when an undoped semiconductor layer, i.e. GaN, is in contact with a semiconductor layer doped with iron, i.e. GaN:Fe, the iron impurities can diffuse out of the semiconductor layer doped with iron, (f) also, whether the iron impurities diffuse out of the second buffer layer doped with iron impurities as recited on line 9, and to what extent the iron impurities diffuse out of the second buffer layer into the neighboring first and third buffer layer would depend on numerous conditions such as (i) the growth temperatures of the first, second and third buffer layer, (ii) the material compositions of the first, second and third semiconductor layer, (iii) whether the semiconductor structure has been annealed during the manufacturing process, (iv) how the first, second and third buffer layer were deposited, etc. (two examples of different amounts of diffusion of iron impurities are also shown in Fig. 4 of Ishiguro et al. (US 10,431,656)), none of which Applicants claim in claim 1, and (g) therefore, the limitation “the first buffer layer and the third buffer layer are not actively doped with iron impurities (emphasis added)” recited on line 10 does not specify (i) whether the first and third buffer layer are doped with iron impurities or not, and (ii) if the first and second buffer layer are doped with iron impurities passively or unintentionally, how the iron impurities are distributed inside the first and third buffer layer. Claims 2-9 depend on claim 1, and therefore, claims 2-9 are also indefinite.
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.
Claim 1 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Wang et al. (CN 106601790)
The claim limitation “buffer” specifies an intended use or field of use, and is treated as non-limiting since it has been held that in device claims, intended use must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. In re Casey, 152 USPQ 235 (CCPA 1967); In re Otto, 136 USPQ 458, 459 (CCPA 1963). A claim containing a “recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus” if the prior art apparatus teaches all the structural limitations of the claim. Ex Parte Masham, 2 USPQ 2d 1647 (Bd. Pat. App. & Inter. 1987).
Wang et al. disclose an epitaxial structure (Fig. 1) of a semiconductor device (Title and [0020]-[0027]), the comprising: a substrate (01) ([0041]); and a first semiconductor layer (composite layer including 02-10) ([0041]) located on the substrate, the first semiconductor layer comprising buffer layers (layers 02-06) ([0041]), the buffer layers at least comprising a first buffer layer (04; first unintentionally doped layer), a second buffer layer (05; second intentionally doped layer), and a third buffer layer (06; second unintentionally doped layer) which are arranged in layers, and the second buffer layer being located between the first buffer layer and the third buffer layer; wherein the second buffer layer (05) ([0046]) is doped with iron impurities, and wherein the first buffer layer (04) and the third buffer layer (06) are not actively doped with iron impurities, because (a) as discussed above under 35 USC 112(b) rejection, it is not clear what the phrase “not actively doped” suggests, and (b) therefore, the “unintentionally” doped layers 04/06 corresponding to the claimed first and third buffer layer, respectively, can be referred to as the first and third buffer layer that “are not actively doped with iron impurities.”
Claims 1, 2 and 5 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Cordier et al. (“Subsurface Fe-doped semi-insulating GaN templates for inhibition of regrowth interface pollution in AlGaN/GaN HEMT structures,” Journal of Crystal Growth 310 (2008) pp. 948-954)
The claim limitation “buffer” specifies an intended use or field of use, and is treated as non-limiting since it has been held that in device claims, intended use must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. In re Casey, 152 USPQ 235 (CCPA 1967); In re Otto, 136 USPQ 458, 459 (CCPA 1963). A claim containing a “recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus” if the prior art apparatus teaches all the structural limitations of the claim. Ex Parte Masham, 2 USPQ 2d 1647 (Bd. Pat. App. & Inter. 1987).
Regarding claim 1, Cordier et al. disclose an epitaxial structure (MD or CD in Fig. 2) (first paragraph under 2. Experimental procedure on page 949) of a semiconductor device (HEMT in Title), the comprising: a substrate (Sapphire); and a first semiconductor layer (composite layer formed on Sapphire) located on the substrate, the first semiconductor layer comprising buffer layers (layers between Sapphire and thicker GaN ud), the buffer layers at least comprising a first buffer layer (SI - GaN), a second buffer layer (Fe:N in MD or GaN:Fe in CD), and a third buffer layer (GaN ud 100 nm in MD or GaN ud 90 nm in CD) which are arranged in layers, and the second buffer layer being located between the first buffer layer and the third buffer layer; wherein the second buffer layer (Fe:N in MD or GaN:Fe in CD) is doped with iron impurities, and wherein the first buffer layer (SI - GaN) and the third buffer layer (GaN ud 100 nm in MD or GaN ud 90 nm in CD) are not actively doped with iron impurities, because (a) as discussed above under 35 USC 112(b) rejection, it is not clear what the phrase “not actively doped” suggests, and (b) therefore, the SI - GaN layer and the GaN ud layers with a thickness of 100 nm or 90 nm can be referred to as the first and third buffer layer that “are not actively doped with iron impurities.”
Regarding claims 2 and 5, Cordier et al. further disclose that the second buffer layer (Fe:N in MD or GaN:Fe in CD) is further doped with carbon impurities (Fig. 3(a)), and wherein concentration of carbon impurities of the second buffer layer is less than concentration of iron impurities of the second buffer layer (Fig. 3(b)), because the concentration of iron impurities in the second buffer layer is about 1019 cm-3 as shown in Fig. 3(b), while the concentration of carbon impurities in the second buffer layer is below 1017 cm-2 as shown in Fig. 3(a) (claim 2), wherein the first buffer layer (SI - GaN) is located on a side of the second buffer layer (Fe:N in MD or GaN:Fe in CD) close to the substrate (Sapphire), and wherein the third buffer layer (GaN ud 100 nm in MD or GaN ud 90 nm in CD) is located on a side of the second buffer layer close to a second semiconductor layer (thicker GaN ud or AlGaN); wherein, wherein the first buffer layer has carbon impurities (Fig. 3(a)), and wherein concentration of carbon impurities of the first buffer layer (SI - GaN) is less than or equal to the concentration of carbon impurities of the second buffer layer (Fe:N in MD or GaN:Fe in CD), because (a) Applicants do not specifically claim where the claimed concentrations of carbon impurities are measured, and (b) therefore, when the claimed concentrations of carbon impurities can be measured at their interface, the two claimed concentrations of carbon impurities would be equal to each other; and wherein the third buffer layer (GaN ud 100 nm in MD or GaN ud 90 nm in CD) has carbon impurities (Fig. 3(a)), and wherein concentration of carbon impurities of the third buffer layer is less than the concentration of carbon impurities of the second buffer layer, because (a) Applicants do not specifically claim where the claimed concentrations of carbon impurities are measured, and (b) therefore, the claimed concentrations of carbon impurities can be selected from arbitrary regions of the second and third buffer layer in Fig. 3(a) to satisfy the claim limitation (claim 5).
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.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Cordier et al. (“Subsurface Fe-doped semi-insulating GaN templates for inhibition of regrowth interface pollution in AlGaN/GaN HEMT structures,” Journal of Crystal Growth 310 (2008) pp. 948-954) The teachings of Cordier et al. are discussed above.
Cordier et al. further disclose for the epitaxial structure according to claim 2 that the concentration of carbon impurities of the second buffer layer (Fe:N in MD or GaN:Fe in CD) satisfies a second preset range, and wherein the second preset range is 10¹⁶ cm-3 ~ 10¹⁷ cm-3, see Fig. 3(a).
Cordier et al. differ from the claimed invention by not showing that the concentration of iron impurities of the second buffer layer satisfies a first preset range, wherein the first preset range is 10¹⁶ cm-3 ~ 5·1018 cm-3.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the concentration of iron impurities of the second buffer layer can satisfy a first preset range, wherein the first preset range can be 10¹⁶ cm-3 ~ 5·1018 cm-3, because (a) the concentration of iron impurities shown in Fig. 3(b) of Cordier et al. is approximately around 5·1018 cm-3, and (b) the concentration of iron impurities should be controlled and optimized to obtain desired insulating characteristics and dielectric constant of the overall buffer layer structure of Cordier et al.
Claims 4, 8 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (CN 106601790) The teachings of Wang et al. are discussed above.
Regarding claim 4, Wang et al. differ from the claimed invention by not showing that a thickness of the second buffer layer is d₂, and wherein 200nm≤ d₂≤800 nm.
Wang et al. further disclose that a thickness of the second buffer layer (05) is 100nm-300nm ([0046]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that a thickness of the second buffer layer disclosed by Wang et al. can be in the claimed thickness range of 200nm≤ d₂≤800 nm, because the thickness of the second buffer layer 05 disclosed by Wang et al. overlaps with the claimed range.
Regarding claim 8, Wang et al. further disclose that the concentration of iron impurities in the first buffer layer (04) is substantially 0, especially because Applicants do not specifically claim how close to 0 is “substantially 0”.
Wang et al. differ from the claimed invention by not showing that concentration of iron impurities in the third buffer layer (06) is less than 10¹⁶ cm⁻³.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that concentration of iron impurities in the third buffer layer (06) can be less than 10¹⁶ cm⁻³, because (a) the third buffer layer 06 disclosed by Wang et al. is a second unintentionally doped layer, and (b) therefore, the claimed concentration of iron impurities can be minimized by controlling growth conditions to obtain desired insulating characteristics and dielectric constant of the overall buffer layer.
Regarding claim 9, Wang et al. further disclose that the concentration of iron impurities in the third buffer layer (06) is substantially 0, especially because Applicants do not specifically claim how close to 0 is “substantially 0”.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Kotani et al. (US 9,166,031)
Ishiguro et al. (US 9,269,799)
Cheng et al. (US 11,469,101)
Nakata et al. (US 2012/0025203)
Cheng et al. (US 11,848,205)
Sato et al. (US 10,553,674)
Ishiguro et al. (US 10,992,269)
Ishiguro et al. (US 9,184,241)
Hallin et al. (US 9,306,009)
Wan et al. (US 9,608,075)
Chen et al. (US 10,109,736)
Hu et al. (US 2016/0293707)
Beach et al. (US 8,431,960)
Laboutin et al. (US 9,076,812)
Sato et al. (US 10,833,184)
Leone et al. (“Suppression of Iron Memory Effect in GaN Epitaxial Layers,” Physic Status Solidi B 255 (2018) 1700377)
Huang et al. (“The Characteristics of 6-Inch GaN on Si RF HEMT with High Isolation Composited Buffer Layer Design,” Electronics 10 (2021) 46)
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAY C KIM whose telephone number is (571) 270-1620. The examiner can normally be reached 8:00 AM - 6:00 PM EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Joshua Benitez can be reached at (571) 270-1435. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JAY C KIM/Primary Examiner, Art Unit 2815
/J. K./Primary Examiner, Art Unit 2815 February 12, 2026