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 Arguments
Applicant’s arguments with respect to claims 1-2 and 4-14 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Objections
Claim 4 is objected to because of the following informalities:
The limitation “1-3 x 108 cm2” of claim 4 should read “1-3 x 108 cm-2.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-2 and 4-14 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claims contain subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventors, at the time the application was filed, had possession of the claimed invention. Claim 1 recites “modifying growth conditions by changing epitaxial deposition parameters after formation of the random-microgrooved template to form lateral epitaxy from at least one sidewall of the at least one AlN layer to form coalesced layers of the at least one AlN layer and substrate while maintaining one or more enclosed void regions at the coalescence front containing at least one air pocket containing at least one air pocket, wherein the at least one air pocket is retained at a coalescence region and relieves residual strain between adjacent portions of the coalesced layers during growth of the crack-free AlN layers” which contains the amended limitations “while maintaining one or more enclosed void regions at the coalescence front containing at least one air pocket” and “relieves residual strain between adjacent portions of the coalesced layers during growth of the crack-free AlN layers”. These limitations were not described in the specification or shown in the figures at the time the application was filed. Claims 2 and 4-14 are rejected under 35 U.S.C. 112(a) insofar as they depend upon and require all the limitations of claim 1 as claimed, including new matter.
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 and 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 “providing a substrate comprising sapphire and configured for pulsed epitaxial growth of a random-microgrooved AlN template that subsequently forms strain-relieving air pockets during lateral epitaxial coalescence” which is indefinite since it is unclear how the “substrate comprising sapphire” is structurally distinguished from other sapphire substrates disclosed in prior art due to the underlined functional language above.
Additionally, claim 1 recites inter alia “wherein the at least one air pocket… relieves residual strain between adjacent portions of 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.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 2 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. Claim 2 recites “The method of claim 1, wherein the substrate comprises sapphire and the at least one AlN layer is formed thereon via the pulsed epitaxial growth process to produce the random-microgrooved template.” Amended claim 1 recites the limitations “… providing a substrate comprising sapphire… forming at least one AlN layer upon the substrate via a pulsed epitaxial growth process such that the AlN layer is configured as a random-microgrooved template…” which includes all the limitations of claim 2. Thus, claim 2 fails to further limit the subject matter disclosed by claim 1. Applicant may cancel the claim, amend the claim to place the claim in proper dependent form, rewrite the claim in independent form, or present a sufficient showing that the dependent claim complies with the statutory requirements.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-2 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over 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) in view of Hirayama et al. (US 20090057646 A1; hereinafter Hirayama).
Regarding claim 1, FIGS. 1(b), 2(d), 3(a) of Zeimer teach a method for growing crack free AlN layers comprising: providing a substrate comprising sapphire (c-plane sapphire substrate § 2. Experimental ¶ 1 - “c-plane sapphire substrate”); forming at least one AlN layer (AlN layer shown in FIG. 1(b) after etching) upon the substrate via epitaxy (“500 nm thick AlN layers were grown by MOVPE” § 2. Experimental ¶ 1) such that the AlN 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, wherein at least one air pocket (gaps shown in coalesced AlN in FIG. 3(a)) is retained at a coalescence region (region where AlN coalesces shown in FIG. 3(a)) and relieves residual strain between adjacent portions of the coalesced layers during growth of the crack-free AlN layers.
Regarding the language “relieves residual strain between adjacent portions of the coalesced layers during growth of the crack-free AlN 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 “relieves residual strain between adjacent portions of the coalesced layers during growth of the crack-free AlN 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 the language “configured for pulsed epitaxial growth of a random-microgrooved AlN template that subsequently forms strain-relieving air pockets during lateral epitaxial coalescence” 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 “configured for pulsed epitaxial growth of a random-microgrooved AlN template that subsequently forms strain-relieving air pockets during lateral epitaxial coalescence” is simply the sapphire 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.
The Examiner also notes the limitation “while maintaining one or more enclosed void regions at the coalescence front containing at least one air pocket” is new matter as indicated in the rejection under 35 U.S.C. 112(a) above.
Zeimer does not teach forming the at least one AlN layer upon the substrate via a pulsed epitaxial growth process in which precursor supply is temporally modulated to form the random-microgrooved template rather than being lithographically defined.
FIGS. 1A-6 of Hirayama teach a method for growing crack free AlN layers (15 ¶ [0053]) comprising: providing a substrate (1) comprising sapphire (¶ [0046]) and configured for pulsed epitaxial growth (¶ [0006][0048] ‘pulsed supply growth’) of a random-microgrooved AlN template (e.g. 3); forming at least one AlN layer (3, 5, 7, 11, 15) upon the substrate via a pulsed epitaxial growth process ((A) ¶ [0006],[0048] ‘pulsed supply growth’) in which precursor supply (NH3) is temporally modulated (see FIG. 3 ¶ [0050]-[0051]) to form the random-microgrooved template (3, see FIG. 1B (A)) such that the AlN layer (3) is configured as a random-microgrooved template (3, see FIG. 1B (A)) having non-periodic microgrooves (micro-grooves shown in FIG. 1B (A)) distributed across the AlN growth surface (sapphire substrate 1) rather than a lithographically defined periodic ridge-and-trench pattern (¶ [0048]); and modifying growth conditions (e.g. conditions shown in FIG. 2) by changing epitaxial deposition parameters (3 grown at high temperature and pressure, 5 grown at low temperature and pressure ¶ [0049]) after formation of the random-microgrooved template (3) to form lateral epitaxy ((B) ‘pulsed supply enhanced lateral growth’) from at least one sidewall of the at least one AlN layer (3, see FIG. 1B (B) ¶ [0048]) to form coalesced layers of the at least one AlN layer (5) and substrate (1 ¶ [0048]).
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 for growing crack-free AlN layers taught by Zeimer with the method for growing crack-free AlN layers taught by Hirayama for the purpose of suppressing edge dislocations, improving flatness, and forming a crack-free AlN layer (¶ [0053]).
Regarding claim 2, Zeimer as modified teaches the method of claim 1, and FIGS. 1A-6 of Hirayama further teach wherein the substrate (1) comprises sapphire (¶ [0046]), wherein the at least one AlN layer (3, 5, 7, 11, 15) is formed on the substrate (1) via the pulsed epitaxial growth process ((A) ¶ [0006],[0048] ‘pulsed supply growth’) to produce the random-microgrooved template (3).
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) after formation of the coalesced AlN layers containing the at least one air pocket (gaps shown in coalesced AlN in FIG. 3(a)).
Claims 4 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Zeimer in view of Hirayama, and further in view of Cardwell et al. (US 20210246571 A1; hereinafter Cardwell).
Regarding claim 4, Zeimer as modified 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) after lateral epitaxial coalescence of the random-microgrooved template (see FIG. 3(a)).
Zeimer as modified 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 as modified teaches the method of claim 1.
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.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Zeimer in view of Hirayama, and further in view of Kamikawa et al. (US 20210013365 A1; hereinafter Kamikawa).
Regarding claim 6, Zeimer as modified teaches the method of claim 1.
Zeimer as modified 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 Hirayama, and further 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, and FIG. 3(a) of Zeimer further teaches further comprising, forming an ultrawide band gap substrate (Al0.5Ga0.5N layer grown on AlN) from the coalesced crack-free AlN layers (AlN in FIG. 3(a)) produced by 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, wherein the ultrawide band gap substrate is formed from the crack-free AlN layers produced by claim 1.
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 Hirayama and 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, and Zhou further teaches 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”; FIGS. 1(a)-(b), para. 4/line 17-22, and para. 5/lines 1-16).
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 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 Hirayama, and further in view of Gu et al. (US 20170133295 A1; hereinafter Gu), Cardwell, and Imanishi et al. (US 20080197359 A1; hereinafter Imanishi).
Regarding claim 10, Zeimer as modified teaches the method of claim 1.
Zeimer as modified 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 Hirayama, and further in view of Gu.
Regarding claim 11, Zeimer as modified teaches the method of claim 1, and FIG. 3(a) of Zeimer further teaches formation of coalesced crack-free AlN layers (region where AlN coalesces shown in FIG. 3(a)) containing the at least one air pocket (gaps shown in coalesced AlN in FIG. 3(a) in region where AlN coalesces).
Zeimer as modified 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 Hirayama, and further in view of Pinnington et al. (US 7732301 B1; hereinafter Pinnington), Sung et al. (US 20190259910 A1; hereinafter Sung), and Zhou.
Regarding claim 12, Zeimer as modified teaches the method of claim 1, and FIG. 3(a) of Zeimer further teaches at least one AlN layer formed as the crack-free coalesced layer (region where AlN coalesces shown in FIG. 3(a)) containing at least one air pocket (gaps shown in coalesced AlN in FIG. 3(a)).
Zeimer as modified 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 FIG. 1 of Sung further 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]).
FIGS. 2A-2N of Pinnington further teach wherein the submount plate is Cu or CuW (col. 41/lines 38-42) and is introduced to the at least one AlN layer (at least one of 30, see FIG. 2M) after formation of a reflective layer (40, see FIGS. 2J-2N col. 36/lines 40-42).
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, and FIG. 3(a) of Zeimer further teaches at least one AlN layer formed as the crack-free coalesced layer (region where AlN coalesces shown in FIG. 3(a)).
Zeimer does not teach further comprising introducing at least one GaN layer and at least one low temperature AlN 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 AlN 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
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/Nora T. Nix/Assistant Examiner, Art Unit 2891
/MATTHEW C LANDAU/Supervisory Patent Examiner, Art Unit 2891
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