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 1-2,4-14 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. Claim 1 recites inter alia “wherein the at least one air pocket relieves strain amongst the coalesced layers” which is indefinite since 1) it is unclear what the strain is being relieved relative to, and 2) it has been held that a vice of functional claiming occurs "when the inventor is painstaking when he recites what has already been seen, and then uses conveniently functional language at the exact point of novelty", MPEP 2173.05(g) wherein in the instant case it is unclear whether the mere presence of air pockets is sufficient to relieve strain or what additional structure is required, if any, to achieve the claimed function. Claims 2,4-14 are rejected insofar as they depend upon and include the indefinite language of claim 1.
Response to Arguments
Applicant's arguments filed 01/08/2026 have been fully considered but they are not persuasive.
Regarding claim 1, Applicant argues FIG. 1(b) of Zeimer does not display “random microgrooving”. Instead, Applicant argues, FIG. 1(b) of Zeimer shows precise grooves, specifically etched at selected depths forming uniform structures across the substrate surface.
However, FIG. 2(d) of Zeimer shows an AFM image of the surface of an ELO-AlN layer grown on AlN/sapphire template with an etch depth of 1.5 micron (i.e. “deeply etched” as referenced in the caption of FIG. 1(b)). FIG. 2(d) of Zeimer clearly shows random microgrooves formed in the ELO-AlN layer shown in FIG. 1(b). Even disregarding the AFM image shown, variations in the dimensions of the template shown in FIG. 1(b) exist (e.g. surface roughness, variations in height and etch depth). A surface free of variations/surface roughness cannot be achieved and attempts to create such a smooth surface would result in significant increases in both manufacturing costs and time.
Thus, the prior rejections under 35 U.S.C. § 102 and 103 stand. See below.
Claim Rejections - 35 USC § 102
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 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 1-2 and 5 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Zeimer et al. (U. Zeimer, V. Kueller, A. Knauer, A. Mogilatenko, M. Weyers, M. Kneissl, High quality AlGaN grown on ELO AlN/sapphire templates, Journal of Crystal Growth, Volume 377, 2013, Pages 32-36, ISSN 0022-0248; hereinafter Zeimer).
Regarding claim 1, FIGS. 1(b), 2(d), 3(a) of Zeimer teach a method for growing crack free AIN layers comprising: providing a substrate (c-plane sapphire substrate § 2. Experimental ¶ 1 - “c-plane sapphire substrate”); forming at least one AIN layer (AlN layer shown in FIG. 1(b) after etching) upon the substrate via pulsed epitaxy (“500 nm thick AlN layers were grown by MOVPE” § 2. Experimental ¶ 1) such that the AIN layers (AlN layer) is configured as a random-microgrooved template (i.e. ridges comprising etched AlN/sapphire); and modifying growth conditions to form lateral epitaxy from at least one sidewall of the at least one AlN layer to form coalesced layers (§ 2. Experimental ¶ 1 “the templates were overgrown with AlN… until coalescence”) of the at least one AlN layer and substrate containing at least one air pocket (gaps shown in coalesced AlN in FIG. 3(a)), wherein the at least one air pocket relieves strain amongst the coalesced layers.
Regarding the language “wherein the at least one air pocket relieves strain amongst the coalesced layers” the Examiner notes this language constitutes functional language and while features of an apparatus may be recited either structurally or functionally, claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function. In re Schreiber, 128 F.3d 1473, 1477-78, 44 USPQ2d 1429, 1431-32 (Fed. Cir. 1997). As best can be determined by the Examiner from the specification of the present application, the structure which performs the function “wherein the at least one air pocket relieves strain amongst the coalesced layers” is simply the existence of the at least one air pocket in the AlN layers and substrate, a structure which is clearly present in the device of Zeimer. Therefore, it appears the structure of Zeimer is capable of performing the function required by the claim language.
Regarding claim 2, Zeimer teaches the method of claim 1, and FIG. 3(a) of Zeimer further teaches wherein the substrate comprises sapphire (§ 2. Experimental ¶ 1 “c-plane sapphire substrate”).
Regarding claim 5, Zeimer teaches the method of claim 1 and FIG. 3(a) of Zeimer further teaches further comprising, forming an ultrawide band gap AlxGa1-xN template (Al0.5Ga0.5N layer grown on AlN) over the substrate (sapphire substrate § 3.2.1 ¶ 1).
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 4 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Zeimer in view of Cardwell et al. (US 20210246571 A1; hereinafter Cardwell).
Regarding claim 4, Zeimer teaches the method of claim 1 and Zeimer further teaches wherein the at least one AlN layer (ELO AlN) has a screw defect density of value of 5.5 x 107 cm-2 and an edge defect density of 8.2 x 108 cm-2 (Table 1 – 0.25° to m miscut).
Zeimer does not teach wherein the at least one AlN layer has a defect density value of substantially 1-3 x 108 cm-2.
FIGS. 1A-T, 3A-3E, 4A-C of Cardwell teach a method for growing crack free AlN layers (e.g. FIGS. 1A-T, 3A-3E) comprising: providing a substrate (101 ¶ [0079]); forming at least one AlN layer (213 ¶ [0010]-[0011],[0111]) upon the substrate (101) via epitaxy (¶ [0033], [0112]) such that the AlN layers (213) is configured as a random-microgrooved (223) template (see FIG. 3C ¶ [0112]); modifying growth conditions to form lateral epitaxy (continued lateral epitaxial growth of 213) from at least one sidewall of the at least one AlN layer (sidewall(s) of 213 ¶ [0113]); and wherein the at least one AlN layer (213) has a defect density value of substantially 1-3 x 108 cm-2 (¶ [0117]).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of for growing crack free AlN layers taught by Zeimer with the method for growing crack free AlN layers taught by Cardwell for the purpose of lowering the defect density of the AlN layers (¶ [0117]) and since it has been held that “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, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955), In re Hoeschele, 406 F.2d 1403, 160 USPQ 809 (CCPA 1969), wherein in the instant case the defect density of AlN layers determines the resulting growth conditions and electric properties making it a result effective variable, In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977), and MPEP 2144.05 Obviousness of Ranges II. OPTIMIZATION OF RANGES A. Optimization Within Prior Art Conditions or Through Routine Experimentation B. Only Result-Effective Variables Can Be Optimized.
Regarding claim 7, Zeimer teaches the method of claim 1.
Zeimer does not teach further comprising, conducting laser lift-off of the at least one AIN layer.
FIGS. 1A-T, 3A-3E, 4A-C of Cardwell teach a method for growing crack free AlN layers (e.g. FIGS. 1A-T, 3A-3E) comprising: providing a substrate (101 ¶ [0079]); forming at least one AlN layer (213 ¶ [0010]-[0011],[0111]) upon the substrate (101) via epitaxy (¶ [0033], [0112]) such that the AlN layers (213) is configured as a random-microgrooved (223) template (see FIG. 3C ¶ [0112]); modifying growth conditions to form lateral epitaxy (continued lateral epitaxial growth of 213) from at least one sidewall of the at least one AlN layer (sidewall(s) of 213 ¶ [0113]); and conducting laser lift-off of the at least one AlN layer (213 ¶ [0119]).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of for growing crack free AlN layers taught by Zeimer with the method for growing and lifting-off crack free AlN layers taught by Cardwell for the purpose of increasing throughput.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Zeimer in view of Kamikawa et al. (US 20210013365 A1; hereinafter Kamikawa).
Regarding claim 6, Zeimer teaches the method of claim 1.
Zeimer does not teach wherein the at least one AlN layer random-microgrooved template is 16-25 µm thick.
Kamikawa teaches a method of fabricating a semiconductor device comprising growing at least one III-nitride layer (105 ¶ [0074]) configured as a random-microgrooved template; wherein the at least one III-nitride layer (105) is grown through lateral epitaxial overgrowth (¶ [0014]) and epitaxy ceases prior to adjacent III-nitride layers (105) coalescing (¶ [0020],[0079]); and wherein the at least one AlN layer random-microgrooved template (105) is 20 µm thick (¶ [0187]).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method for growing crack free AlN layers taught by Zeimer with the method of growing III-nitride layers taught by Kamikawa since it has been held that “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, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955), In re Hoeschele, 406 F.2d 1403, 160 USPQ 809 (CCPA 1969), wherein in the instant case the thickness of the AlN layer determines the resulting device dimensions making it a result effective variable, In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977), and MPEP 2144.05 Obviousness of Ranges II. OPTIMIZATION OF RANGES A. Optimization Within Prior Art Conditions or Through Routine Experimentation B. Only Result-Effective Variables Can Be Optimized.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Zeimer in view of Zhou et al. (L. Zhou, J. E. Epler, M. R. Krames, W. Goetz, M. Gherasimova, Z. Ren, J. Han, M. Kneissl, N. M. Johnson; Vertical injection thin-film AlGaN/AlGaN multiple-quantum-well deep ultraviolet light-emitting diodes. Appl. Phys. Lett. 11 December 2006; 89 (24): 241113; hereinafter Zhou).
Regarding claim 8, Zeimer teaches the method of claim 1.
Zeimer does not teach further comprising, fabricating at least one vertically conducting UWBG AlxGa1-xN device via: growing at least one epilayer over an ultrawide band gap AlxGa1-xN substrate to form at least one wafer; bonding the at least one wafer to a temporary carrier; performing laser liftoff of the at least one wafer; forming at least one backside n-contact on a N-polar face of the at least one wafer; bonding the at least one backside n-contact to at least one metallic preform; removing the temporary carrier; and fabricating at least one vertical conduction device on a side of the at least one wafer opposite the n-contact.
FIGS. 1(a)-(b), para. 4/line 17-22, and para. 5/lines 1-16 of Zhou teach fabricating at least one vertically conducting UWBG AlxGa1-xN device (FIGS. 1(a)-(b)) via: growing at least one epilayer (MQW layer, p-AlGaN layer, p-GaN layer) over an ultrawide band gap AlxGa1-xN substrate (n-AlGaN layer) to form at least one wafer (n-AlGaN layer, MQW layer, p-AlGaN layer, and p-GaN layer); bonding the at least one wafer (n-AlGaN layer, MQW layer, p-AlGaN layer, and p-GaN layer) to a temporary carrier ("metal-coated carrier wafer"); performing laser liftoff ("laser-assisted liftoff") of the at least one wafer (n-AlGaN layer, MQW layer, p-AlGaN layer, and p-GaN layer); forming at least one backside n-contact on a N-polar face of the at least one wafer (“exposing the nitrogen-terminated n-type AlxGa1-xN contact layer”); bonding the at least one backside n-contact (nitrogen-terminated n-type AlxGa1-xN contact layer) to at least one metallic preform (cathode grid/n-type contact); removing the temporary carrier ("devices are singulated, mounted to a heat sink, and wire bonded"); and fabricating at least one vertical conduction device (p-contact/reflector, formed prior to laser liftoff) on a side of the at least one wafer opposite the n-contact (cathode grid/n-type contact, see FIG. 1(b)).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method for growing crack free AlN layers taught by Zeimer with the method of fabricating at least one vertically conducting UWBG AlxGa1-xN device taught by Zhou for the purpose of enhancing the functionality of the UWBG AlxGa1-xN device taught by Zhou by providing large reductions in the concentrations of dislocations in III-nitride layers (§ 3.1 ¶ 3, Table 1 of Zeimer) since it has been held in KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007), MPEP 2143(I)(A), that examples of rationales that may support a conclusion of obviousness include combining prior art elements according to known methods to yield predictable results, wherein in the instant case the method of fabricating at least one UWBG AlxGa1-xN device is taught in the art, one having ordinary skill in the art could have combined the method of fabricating at least one UWBG AlxGa1-xN device with Zeimer with each element performing the same function as it does separately, and one having ordinary skill in the art would have found the combination predictable since the components are commonly used together.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Zeimer in view of Zhou, and further in view of Khan et al. (US 20110012089 A1; hereinafter Khan2).
Regarding claim 9, Zeimer as modified teaches the method of claim 8.
Zeimer as modified does not teach further comprising reverse grading, from AlGaN to GaN, in an area containing the at least one n-contact.
FIGS. 4 and 5 of Kahn2 teach light-emitting devices including a buffer layer (404 ¶ [0064]) comprising reverse grading, from AlGaN to GaN, in an area (e.g. UV light-emitting structure 12) containing the at least one n-contact (401 ¶ [0022],[0063]).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method for growing crack free AlN layers taught by Zeimer with the UV light-emitting device taught by Khan2 for the purpose of controlling thin-film stress and mitigating epilayer cracking (¶ [0010]).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Zeimer in view of Gu et al. (US 20170133295 A1; hereinafter Gu), and further in view of Cardwell and Imanishi et al. (US 20080197359 A1; hereinafter Imanishi).
Regarding claim 10, Zeimer teaches the method of claim 1.
Zeimer does not teach further comprising, wafer bonding and excimer laser liftoff to form an N-polar AlN substrate for growth of a high-electron-mobility transistor.
FIGS. 1A-2 of Gu teach a method of fabricating a semiconductor structure comprising: providing a substrate (16 ¶ [0024]); forming at least one AlN layer (22 ¶ [0024]-[0025]) upon the substrate (16); wafer bonding (e.g. wafer bonding 26 to 22 ¶ [0025]-[0026]); removing the substrate (16 ¶ [0026]) to form an N-polar GaN substrate (surface BS2 of buffer 20 ¶ [0025],[0030]) for growth of a high-electron mobility transistor (FIG. 5G, note presence of 2DEG).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method for growing crack free AlN layers taught by Zeimer with the method of manufacturing a III-nitride semiconductor device taught by Gu for the purpose of enhancing the functionality of the III-nitride semiconductor device taught by Gu by providing large reductions in the concentrations of dislocations in III-nitride layers (§ 3.1 ¶ 3, Table 1 of Zeimer) since it has been held in KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007), MPEP 2143(I)(A), that examples of rationales that may support a conclusion of obviousness include combining prior art elements according to known methods to yield predictable results, wherein in the instant case the method of fabricating a III-nitride semiconductor device is taught in the art, one having ordinary skill in the art could have combined the method of fabricating a III-nitride semiconductor device with Zeimer with each element performing the same function as it does separately, and one having ordinary skill in the art would have found the combination predictable since the components are commonly used together.
Zeimer as modified does not teach further comprising, conducting laser lift-off of the at least one AlN layer.
FIGS. 1A-T, 3A-3E, 4A-C of Cardwell teach a method for growing crack free AlN layers (e.g. FIGS. 1A-T, 3A-3E) comprising: providing a substrate (101 ¶ [0079]); forming at least one AlN layer (213 ¶ [0010]-[0011],[0111]) upon the substrate (101) via epitaxy (¶ [0033], [0112]) such that the AlN layers (213) is configured as a random-microgrooved (223) template (see FIG. 3C ¶ [0112]); modifying growth conditions to form lateral epitaxy (continued lateral epitaxial growth of 213) from at least one sidewall of the at least one AlN layer (sidewall(s) of 213 ¶ [0113]); and conducting laser lift-off of the at least one AlN layer (213 ¶ [0119]).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of for growing crack free AlN layers taught by Zeimer with the method for growing and lifting-off crack free AlN layers taught by Cardwell for the purpose of increasing throughput.
Zeimer as modified does not teach an N-polar AlN substrate.
Imanishi teaches a HEMT device (e.g. FIG. 2) comprising an AlN buffer layer (102 ¶ [0031]).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method for growing crack free AlN layers taught by Zeimer with the AlN buffer layer taught by Imanishi since it has been held that the selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945), In re Leshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960), and MPEP 2144.07 Art Recognized Suitability for an Intended Purpose.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Zeimer in view of Gu.
Regarding claim 11, Zeimer teaches the method of claim 1.
Zeimer does not teach further comprising, removing the substrate and replacing the substrate with a high-thermal conductivity metal preform.
FIGS. 1A-1F of Gu teach a method of fabricating a semiconductor structure comprising: providing a substrate (16 ¶ [0024]); forming at least one AlN layer (18, 22 ¶ [0024]-[0025]) upon the substrate (16); removing the substrate (16) and replacing the substrate (16) with a high-thermal conductivity metal preform (24, FIGS. 1E-1F show steps where 24 has replaced 16 ¶ [0026]).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method for growing crack free AlN layers taught by Zeimer with the method of replacing the substrate with a high-thermal conductivity metal preform taught by Gu for the purpose of providing a substrate with high heat dissipation (¶ [0004]).
Claims 12-13 are rejected under 35 U.S.C. 103 as being unpatentable over Zeimer in view of Pinnington et al. (US 7732301 B1; hereinafter Pinnington), and further in view of Sung et al. (US 20190259910 A1; hereinafter Sung) and Zhou.
Regarding claim 12, Zeimer teaches the method of claim 1.
Zeimer does not teach further comprising, forming a heat sink via: introducing at least one submount plate to the at least one AlN layer; depositing a Ti/Ni/Ti/Ni/Ti/Ni buffer layer; depositing a Ti/Au wetting layer; depositing AuSn solder followed by soldering; and performing substrate liftoff.
FIGS. 2A-2N of Pinnington teach a method of fabricating a III-nitride semiconductor structure including forming a heat sink (50, 51 col. 41/lines 55-63) via: introducing at least one submount plate (50) to the at least one AlN layer (at least one of 30, see FIG. 2M); depositing a Ti/Au wetting layer (“the adhesion layer is provided prior to the provision of the eutectic bonding layer… comprising Ti/Pt/Au,” not shown, col. 42/lines 21-28); depositing AuSn solder (51) followed by soldering (“eutectic bonding,” i.e. eutectic soldering); and removing the substrate (20, see FIG. 2N).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method for growing crack free AlN layers taught by Zeimer with the method of fabricating a III-nitride semiconductor structure taught by Pinnington for the purpose of enhancing the functionality of the III-nitride semiconductor structure taught by Pinnington by providing large reductions in the concentrations of dislocations in III-nitride layers (§ 3.1 ¶ 3, Table 1 of Zeimer) since it has been held in KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007), MPEP 2143(I)(A), that examples of rationales that may support a conclusion of obviousness include combining prior art elements according to known methods to yield predictable results, wherein in the instant case the III-nitride semiconductor structure is taught in the art, one having ordinary skill in the art could have combined the method of fabricating the III-nitride semiconductor structure with Zeimer with each element performing the same function as it does separately, and one having ordinary skill in the art would have found the combination predictable since the components are commonly used together.
Zeimer as modified does not teach depositing a Ti/Ni/Ti/Ni/Ti/Ni buffer layer.
FIG. 1 of Sung teaches a light-emitting semiconductor device including a Ti/Ni/Ti/Ni/Ti/Ni buffer layer (140) disposed on a reflective layer (132 ¶ [0077],[0101]).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method for growing crack free AlN layers taught by Zeimer with the buffer layer taught by Sung for the purpose of protecting the reflective layer of Pinnington and/or protecting underlying semiconductor layers and providing a current-spreading layer (¶ [0077]).
Zeimer as modified does not teach performing substrate liftoff.
FIGS. 1(a)-(b), para. 4/line 17-22, and para. 5/lines 1-16 of Zhou teach a method of fabricating a light-emitting device including forming metallic contacts and a carrier wafer on a sapphire/GaN substrate and removing the sapphire/GaN substrate by laser-assisted lift-off.
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method for growing crack free AlN layers taught by Zeimer with the laser-assisted lift-off method taught by Zhou for the purpose of mitigating cracking and decreasing fluences necessary to achieve lift-off (para. 4/lines 9-17).
Regarding claim 13, Zeimer as modified teaches the method of claim 12, and Pinnington further teaches wherein the submount plate is Cu or CuW (col. 41/lines 38-42).
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Zeimer in view of Zhou, and further in view of Kim et al. (US 20130069079 A1; hereinafter Kim).
Regarding claim 14, Zeimer teaches the method of claim 5.
Zeimer does not teach further comprising introducing at least one GaN layer and at least one low temperature AIN layer between the AlxGa1-xN template and the substrate.
FIGS. 1(a)-(b), para. 4/line 17-22, and para. 5/lines 1-16 of Zhou further teach further comprising, introducing at least one GaN layer (GaN layer) and at least one low temperature AIN layer (LT-AlN layer) between the AlxGa1-xN template (n-AlGaN layer, p-AlGaN layer) and the substrate (sapphire substrate, see FIG. 1(a)).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method for growing crack free AlN layers taught by Zeimer with the method for growing an AlGaN layer on a sapphire substrate for the purpose of preventing cracking during AlGaN growth (¶ 4 “A GaN template layer is grown first and then followed with a low-temperature metamorphic AlN interlayer to prevent cracking during AlGaN growth…”).
Zeimer as modified does not teach introducing at least one AlN spacer.
FIGS. 1A-E of Kim teach a method of fabricating epitaxial AlN layers (3, 4) on a sapphire substrate (2); wherein the epitaxial AlN layers (3, 4) comprise at least one AlN layer configured as a random-microgrooved template (3) and at least one AlN spacer (4) formed directly above the at least one AlN layer (3).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method for growing crack free AlN layers taught by Zeimer with the method of fabricating AlN layers on a sapphire substrate taught by Kim for the purpose of significantly reducing threading dislocation density while preventing decreases in throughput and increases in manufacturing cost (¶ [0004]-[0006]).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
US 20160359081 A1 – FIG. 3 discloses a heterostructure comprising a stress controlling layer having a thickness with random fluctuations (¶ [0043]).
US 20180286954 A1 – FIG. 3 discloses rough III-N layers.
US 20050118752 A1 – FIG. 5 discloses an AlN layer (¶ [0059]) comprising random and irregular interstices (¶ [0068]).
US 10115589 B2 – FIG. 14 discloses a silicon substrate with rough AlN layers.
US 20210273084 A1 – FIGS. 1 & 2B discloses a rough buffer layer on a silicon substrate (¶ [0018]).
THIS ACTION IS MADE FINAL. 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 Nora T Nix whose telephone number is (571)270-1972. The examiner can normally be reached Monday - Friday 9:00 am - 5:00 pm ET.
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/Nora T. Nix/Assistant Examiner, Art Unit 2891
/MATTHEW C LANDAU/Supervisory Patent Examiner, Art Unit 2891