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 § 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(s) 1-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Gaevski(USPGPUB DOCUMENT: 2018/0315886, hereinafter Gaevski) in view of Pinnington(USPATENT: 7732301, hereinafter Pinnington) and Wierer(USPATENT: 9595616, hereinafter Wierer).
Re claim 1 Gaevski discloses a method for transferring wide and ultrawide bandgap (WBG and UWBG) layers to an engineered substrate, comprising:
performing laser-based lift-off[0071,0072] (LLO) on high-electron mobility transistors[0042] HEMTs[0042] with AIN heat spreading buffer layers(22A/22B)[0045] grown over sapphire substrate material(20)[0044], to remove the sapphire substrate material(20)[0044];
Gaevski does not disclose applying a carrier substrate to the heat spreading buffer layers(22A/22B)[0045] using a bonding agent, to collectively form an engineered substrate; performing laser-based lift-off (LLO) on high-electron mobility transistors (HEMTs) comprising the WBG and UWBG layers, to remove the sapphire substrate material to expose the AIN heat spreading buffer layers attached to the HEMTs; and applying a carrier substrate to the exposed AIN heat spreading buffer layers using a bonding agent, to collectively form an engineered substrate.
Pinnington discloses in Fig 2A-2N applying a carrier substrate (50)[col 41, lines 30-55] to the heat spreading buffer layers(30) [col 41, lines 30-55] using a bonding agent (51)[col42,lines 20-30], to collectively form an engineered substrate.
It would have been obvious to one of ordinary skill in the art before the effective filling date of the invention to apply the teachings of Pinnington to the teachings of Gaevski in order to enable development of smaller light-emitting devices with longer life time, higher output power, and lower cost relative to conventional devices [col1 lines 35-45, Pinnington].
Gaevski and Pinnington does not disclose performing laser-based lift-off (LLO) on high-electron mobility transistors (HEMTs) comprising the WBG and UWBG layers, to remove the sapphire substrate material to expose the AIN heat spreading buffer layers attached to the HEMTs; and applying a carrier substrate to the exposed AIN heat spreading buffer layers using a bonding agent, to collectively form an engineered substrate.
Wierer disclose performing laser-based lift-off (LLO) [col1, lines 45-65] on high-electron mobility transistors (HEMTs) comprising the WBG and UWBG layers [col1, lines 15-40], to remove the sapphire substrate material[col2, lines 5-15] to expose the AIN heat spreading buffer layers attached to the HEMTs[col3, lines 50-65](since AlGaN comprises AlN, this may be interpreted as remove the sapphire substrate material to expose the AIN heat spreading buffer layers attached to the HEMTs);
It would have been obvious to one of ordinary skill in the art before the effective filling date of the invention to apply the teachings of Wierer to the teachings of Gaevski in order to enable the fabrication of smaller devices delivering high output power at high frequencies [col1 lines 30-45, Wierer]. In doing so, applying a carrier substrate to the exposed[col1, lines 15-40 of Wierer] AIN heat spreading buffer layers(22A/22B)[0045] using a bonding agent, to collectively form an engineered substrate.
Re claim 2 Gaevski and Pinnington and Wierer disclose the method according to claim 1, wherein:
the HEMTs[0042] comprise AlGaN/GaN HEMTs[0042];
the laser-based lift-off[0071,0072] (LLO) includes use of an excimer laser having a wavelength of less than 250 nm; and
the AIN heat spreading buffer layers(22A/22B)[0045] are at least 10 um thick.
Re claim 3 Gaevski and Pinnington and Wierer disclose the method according to claim 2, wherein:
the HEMTs[0042] comprise Alo.26Gao.74N/GaN high-electron mobility transistors[0042];
the laser-based lift-off[0071,0072] (LLO) includes use of a 193-nm excimer laser; and
the AIN heat spreading buffer layers(22A/22B)[0045] are about 16 yum thick.
Re claim 4 Gaevski and Pinnington and Wierer disclose the method according to claim 1, wherein the carrier substrate(50)[col 41, lines 30-55 of Pinnington] comprises a heat sink layer.
Re claim 5 Gaevski and Pinnington and Wierer disclose the method according to claim 4, where the heat sink layer comprises copper[col 41, lines 30-55 of Pinnington] and the bonding agent comprises solder.
Re claim 6 Gaevski and Pinnington and Wierer disclose the method according to claim 1, wherein the laser-based lift-off[0071,0072] (LLO) includes using an ultraviolet laser light passed through the sapphire substrate material(20)[0044] to ablate an interface between the AIN heat spreading buffer layers [col2, lines 5-15 of Wierer] and the sapphire substrate material(20)[0044] to release the sapphire substrate material(20)[0044].
Re claim 7 Gaevski and Pinnington and Wierer disclose an engineered substrate made according to the method of claim 1(Fig 2A-2N of Pinnington).
Re claim 8 Gaevski discloses a double transfer method for fabricating WBG and UWBG semiconductor devices without requiring a final polishing step, comprising: forming AIGaN/GaN HEMTs on a layer of AIN heat spreaders(22A/22B)[0045] having a thickness of at least 10 pm, grown over sapphire substrate material(20)[0044]s; applying excimer laser lift-off[0071,0072] to remove the sapphire substrate material(20)[0044]s to expose the layer of AIN heat spreaders(22A/22B)[0045] ;
Gaevski does not disclose using a bonding agent to apply a heat sink layer to the exposed layer of AIN heat spreaders(22A/22B)[0045] ; whereby first transferring off the sapphire substrate material(20)[0044]s and subsequently transferring on a heat sink layer results in engineered formation of WBG and UWBG power devices; forming AIGaN/GaN HEMTs comprising the WBG and UWBG semiconductor devices ; applying excimer laser lift-off to remove the sapphire substrate materials to expose the layer of AIN heat spreaders attached to the AIGaN/GaN HEMTs;
Pinnington discloses in Fig 2A-2N using a bonding agent(51)[col42,lines 20-30] to apply a heat sink layer(50)[col 41, lines 30-55] to the exposed layer of AIN heat spreaders(30) [col 41, lines 30-55] ;
It would have been obvious to one of ordinary skill in the art before the effective filling date of the invention to apply the teachings of Pinnington to the teachings of Gaevski in order to enable development of smaller light-emitting devices with longer life time, higher output power, and lower cost relative to conventional devices [col1 lines 35-45, Pinnington]. In doing so, whereby first transferring off the sapphire substrate material(20)[0044]s and subsequently transferring on a heat sink layer(50)[col 41, lines 30-55 of Pinnington] results in engineered formation of WBG and UWBG power devices.
Gaevski and Pinnington does not disclose forming AIGaN/GaN HEMTs comprising the WBG and UWBG semiconductor devices ; applying excimer laser lift-off to remove the sapphire substrate materials to expose the layer of AIN heat spreaders attached to the AIGaN/GaN HEMTs;
Wierer disclose forming AIGaN/GaN HEMTs comprising the WBG and UWBG semiconductor devices [col1, lines 15-40]; applying laser lift-off to remove the sapphire substrate materials [col2, lines 5-15] to expose the layer of AIN[col3, lines 50-65](since AlGaN comprises AlN, this may be interpreted as remove the sapphire substrate materials [col2, lines 5-15] to expose the layer of AIN) heat spreaders attached to the AIGaN/GaN HEMTs;
It would have been obvious to one of ordinary skill in the art before the effective filling date of the invention to apply the teachings of Wierer to the teachings of Gaevski in order to enable the fabrication of smaller devices delivering high output power at high frequencies [col1 lines 30-45, Wierer]. In doing so, applying excimer laser lift-off[0071,0072] to remove the sapphire substrate materials [col2, lines 5-15]
Re claim 9 Gaevski and Pinnington and Wierer disclose the method according to claim 8, further comprising: before applying excimer laser lift-off[0071,0072], bonding UV tape to a side of the HEMT opposite the sapphire substrate material(20)[0044]s; and after applying a heat sink layer to the exposed layer of AIN heat spreaders(22A/22B)[0045] , removing the UV bonding tape.
Re claim 10 Gaevski and Pinnington and Wierer disclose the method according to claim 8, further comprising, after applying excimer laser lift-off[0071,0072] to remove the sapphire substrate material(20)[0044]s, cleaning the exposed layer of AIN heat spreaders(22A/22B)[0045] .
Re claim 11 Gaevski and Pinnington and Wierer disclose the method according to claim 10, wherein the cleaning comprises cleaning with 1:1 dilute HCI and C12/Ar ICP[col46, lines 1-10 of Pinnington].
Re claim 12 Gaevski and Pinnington and Wierer disclose the method according to claim 10, wherein applying a heat sink layer to the exposed layer of AIN heat spreaders(22A/22B)[0045] comprises bonding the exposed layer of AIN heat spreaders(22A/22B)[0045] to a copper heat sink substrate using In-Pb solder by thermocompression bonding
Re claim 13 Gaevski and Pinnington and Wierer disclose the semiconductor device made according to the method of claim 8(Fig 2A-2N of Pinnington).
Re claim 14 Gaevski discloses a Methodology for forming a layered substrate, comprising:
performing laser-based lift-off[0071,0072] (LLO) on AlGaN high-electron mobility transistors[0042] HEMTs[0042] with ceramic heat spreading buffer layers(22A/22B)[0045] having relatively high thermal conductivity, and grown over sapphire substrate material(20)[0044], to remove the sapphire substrate material(20)[0044]:
Gaevski does not disclose applying a copper heat sink to the ceramic heat spreading buffer layers(22A/22B)[0045] using a bonding agent, to collectively form an engineered layered substrate; to remove the sapphire substrate material to expose the ceramic heat spreading buffer layers attached to the AIGaN HEMTs; and applying a copper heat sink to the exposed ceramic heat spreading buffer layers using a bonding agent,
Pinnington discloses in Fig 2A-2N applying a copper heat sink(50)[col 41, lines 30-55] to the ceramic heat spreading buffer layers(30) [col 41, lines 30-55] using a bonding agent(51)[col42,lines 20-30], to collectively form an engineered layered substrate.
It would have been obvious to one of ordinary skill in the art before the effective filling date of the invention to apply the teachings of Pinnington to the teachings of Gaevski in order to enable development of smaller light-emitting devices with longer life time, higher output power, and lower cost relative to conventional devices [col1 lines 35-45, Pinnington].
Gaevski and Pinnington does not disclose to remove the sapphire substrate material to expose the ceramic heat spreading buffer layers attached to the AIGaN HEMTs; and applying a copper heat sink to the exposed ceramic heat spreading buffer layers using a bonding agent,
Wierer disclose to remove the sapphire substrate material[col2, lines 5-15] to expose the ceramic heat spreading buffer layers[col3, lines 50-65](since AlGaN comprises AlN, this may be interpreted as remove the sapphire substrate material[col2, lines 5-15] to expose the ceramic heat spreading buffer layers) attached to the AIGaN HEMTs;
It would have been obvious to one of ordinary skill in the art before the effective filling date of the invention to apply the teachings of Wierer to the teachings of Gaevski in order to enable the fabrication of smaller devices delivering high output power at high frequencies [col1 lines 30-45, Wierer]. In doing so, applying a copper heat sink(50)[col 41, lines 30-55 of Pinnington] to the exposed ceramic heat spreading[col2, lines 5-15 of Wierer] buffer layers using a bonding agent,
Re claim 15 Gaevski and Pinnington and Wierer disclose the methodology according to claim 14, wherein the ceramic heat spreading buffer layers(22A/22B)[0045] comprise aluminum nitride (AIN).
Re claim 16 Gaevski and Pinnington and Wierer disclose the methodology according to claim 14, wherein the ceramic heat spreading buffer layers(22A/22B)[0045] comprise III nitride material.
Re claim 17 Gaevski and Pinnington and Wierer disclose the methodology according to claim 14, wherein:
the AlGaN high-electron mobility transistors[0042] HEMTs[0042] comprise ultrawide bandgap (UWBG) AlGaN HEMTs[0042]; and
the ceramic heat spreading buffer layers(22A/22B)[0045] comprise aluminum nitride (AIN) having a thickness of at least 10 um.
Re claim 18 Gaevski and Pinnington and Wierer disclose the methodology according to claim 17, wherein the laser-based lift-off[0071,0072] (LLO) is performed on Alo.26Gao.74N/GaN HEMT’s by a 193-nm ArF excimer laser and transferred onto a copper heat sink(50)[col 41, lines 30-55 of Pinnington] bonded by In-Pb solder.
Re claim 19 Gaevski and Pinnington and Wierer disclose a layered substrate made according to the methodology of claim 14(Fig 2A-2N of Pinnington).
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-19 have been considered but are moot because the arguments do not apply to any of the references being used in the current rejection.
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.
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/PATRICIA D VALENZUELA/Primary Examiner, Art Unit 2812
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