Cornell Ultrawide Bandgap Nitride Electronics Group

Electronic devices using GaN and AlN are ushering in a new era of high-power RF and mm-wave, and high voltage applications. The devices we make feed off of years of meticulously (and laboriously!) developed in-house materials epitaxy and processes for quantized structures, coupled with a clear understanding of the physics of polarization, heterojunctions, tunneling and breakdown, and related physical properties. Because of this holistic team approach, we continue to push the limits of ultrafast transistors, high voltage transistors, resonant tunneling oscillators, RF filters, and low-power transistors for sub-Boltzmann switching, to redefine what is possible with semiconductors . We are grateful to collaborators from industry who continue to support our exploration and take research to the market.

Our papers in this area in chronological order

2022

372 APL Epitaxial ScAlN on GaN exhibits attractive high-K dielectric properties

371 APL Distributed polarization-doped GaN p-n diodes with near-unity ideality factor and avalanche breakdown voltage of 1.25 kV

367 PSS(a) Photoelectric generation coefficient of beta-Ga2O3 during exposure to high-energy ionizing radiation

366 JAP A unified thermionic and thermionic-field emission model for ideal Schottky reverse-bias leakage current

364 Adv. Elect. Mat. Very high density (>1e14/cm2) polarization-induced 2D hole gases observed in undoped pseudomporphic InGaN/AlN heterostructures

363 APL Quantitative scanning microwave microscopy of 2D electron and hole gases in AlN/GaN heterostructures

2021

360 IEEE TED Breakdown mechanisms in beta-Ga2O3 trench-MOS Schotty barrier diodes

359 APEX Influence of collector doping setback in the quantum transport characteristics of GaN/AlN resonant tunneling diodes

357 DRC Large-signal response of AlN/GaN/AlN HEMTs at 30 GHz

356 IEEE MTT SiC substrate-integrated waveguides for high-powe monolithic integrated circuits above 110 GHz

353 APL Polarization-induced 2D hole gases in pserudomorphic undoped GaN/AlN heterostructures on single-crystal AlN substrates

351 PSS(a) in-situ crystalline AlN passivation for reduced RF disperson in strained-channel AlN/GaN/AlN HEMTs

350 IEEE TED On-resistance of Ga2O3 trench-MOS Schottky-barrier diodes: Role of sidewall interface trapping

347 SST Next-generation electronics on the ultrawide-bandgap aluminum nitride platform

345 JAP High-conductivity polarization-induced 2D hole gases in undoped GaN/AlN heterojunctions enabled by impurity blocking layers

340 APL MBE growth and donor doping of coherent ultrawide bandgap AlGaN alloy layers on single-crystal AlN substrates

338 Science Advances Crystal orientation dictated epitaxy of ultrawide bandgap 5.4-8.6 eV alpha-(AlGa)2O3 on m-plane sapphire

337 PSSR Electric Fields and Surface Fermi Level in Undoped GaN/AlN 2D Hole Gas Heterostructures

333 JEDS First RF Power Operation of AlN/GaN/AlN HEMTs with >3 A/mm and 3.3 W/mm at 10 GHz

332 IEDM GaN/AlN p-channel HFETs with Imax>420 mA/mm and ~20 GHz fT/fmax

331 DRC Very High Parallel-Plane Surface Electric Field of 4.3 MV/cm in Gallium Oxide Schottky Barrier Diodes with PtOx Contacts

329 Phys. Rev. Research Unified ballistic transport relation for anisotropic dispersions and generalized dimensions

328 APL Thermionic emission or tunneling? The universal transition electric field for ideal Schottky reverse leakage current: a case study in beta-GaOx

326 APL N-Polar GaN/AlN Resonant Tunneling Diodes

324 TED Prospects for Wide-Bandgap and Ultra-Wide-Bandgap CMOS Devices

323 TED Impact of Residual Carbon on Avalanche Voltage and Stability of Polarization-Induced Vertical GaN p-n Junction

2020

322 TED Guiding Principles for Trench Schottky Barrier Diodes Based on Ultrawide Bandgap Semiconductors: A Case Study in Ga2O3

321 TED Trapping and De-Trapping Mechanisms in beta-Ga2O3 Vertical FinFETs Investigated by Electro-Optical Measurements

310 APL Near-ideal reverse leakage current and practical maximum electric field in beta-Ga2O3 Schottky barrier diodes

308 PSS(a) All-Epitaxial Bulk Acoustic Wave Resonators

307 PSS(a) Degradation mechanisms of GaN-based vertical devices: a review

305 EDL GaN HEMTs on Silicon with Regrown Ohmic Contacts and fT/fMax Oscillation Frequencies of 250/204 GHz

304 Phys. Rev. Applied Fighting Broken Symmetry with Doping: Towards Polar Resonant Tunneling Diodes with Symmetric Characteristics

302 APL Gallium nitride tunneling field-effect transistors exploiting polarization fields

299 PSS(b) MBE growth of large-area GaN/AlN 2D hole gas heterostructures

298 APL Materials Fully transparent field-effect transistor with high drain current and on-off ratio

2019

293 IEDM GaN/AlN Schottky-gate p-channel HFETs with InGaN contacts and 100 mA/mm on-current

292 IEDM Single and multi-fin normally-off Ga2O3 vertical transistors with a breakdown voltage over 2.6 kV

290 EDL Field-Plated Ga2O3 Trench Schottky Barrier Diodes with a BV2/Ronsp of up to 0.95 GW/cm2

285 TED Breakdown Walkout in Polarization-Doped Vertical GaN Diodes

283 Science A polarization-induced 2D Hole Gas in undoped Gallium Nitride Quantum Wells

282 ECS Trans. GaN-Based Multiple 2DEG Channel BRIDGE (Buried Dual Gate) HEMT Technology for High Power and Linearity

277 EDL High Breakdown Voltage in RF AlN/GaN/AlN Quantum Well HEMTs

275 APL Wurtzite phonons and the mobility of a GaN/AlN 2D hole gas

270 APEX Fin-channel orientation dependence of forward conduction in kV-class Ga2O3 trench Schottky barrier diodes

269 JJAP Realization of GaN PolarMOS using selective-area regrowth by MBE and its breakdown mechanisms

266 Phys. Rev. Applied Broken symmetry effects due to polarization on resonant tunneling transport in double-barrier nitride heterostructures

2018

263 IEDM 2.44 kV Ga2O3 vertical trench Schottky barrier diodes with very low reverse leakage current

262 IEDM Demonstration of avalanche capability in polarization-doped vertical GaN pn diodes: study of walkout due to residual carbon concentration

261 EDL Gate-recessed E-mode p-channel HFET with high on-current based on GaN/AlN 2D hole gas

260 APL 1230 V β-Ga2O3 trench Schottky barrier diodes with an ultra-low leakage current of <1 μA/cm2

259 APL Breakdown mechanism in 1 kA/cm2 and 960 V E-mode β-Ga2O3 vertical transistors

258 DRC 1.5 kV Vertical Ga2O3Trench-MIS Schottky Barrier Diodes

257 DRC Realization of the First GaN Based Tunnel Field-Effect Transistor

256 Micro. Rel. Degradation of GaN-on-GaN vertical diodes submitted to high current stress

255 TED Development of GaN Vertical Trench-MOSFET With MBE Regrown Channel

254 JAP Comparison of unit cell coupling for grating-gate and high electron mobility transistor array THz resonant absorbers

253 APL Activation of buried p-GaN in MOCVD-regrown vertical structures

251 EDL Enhancement-Mode Ga2O3 Vertical Transistors With Breakdown Voltage >1 kV

250 APL Room temperature microwave oscillations in GaN/AlN resonant tunneling diodes with peak current densities up to 220 kA/cm2

247 TED Steep Sub-Boltzmann Switching in AlGaN/GaN Phase-FETs With ALD VO2

2017

244 Adv. Elect. Mat. Ultrawide Bandgap Semiconductors: Research Opportunities and Challenges

242 DRC Vertical fin Ga2O3power field-effect transistors with on/off ratio >10^9

241 DRC GaN vertical nanowire and fin power MISFETs

240 DRC 600 V GaN vertical V-trench MOSFET with MBE regrown channel

238 DRC Wide-bandgap Gallium Nitride p-channel MISFETs with enhanced performance at high temperature

237 DRC Experimental demonstration of enhanced terahertz coupling to plasmon in ultra-thin membrane AlGaN/GaN HEMT arrays

234 Phys. Rev. X New Tunneling Features in Polar III-Nitride Resonant Tunneling Diodes

232 APL Terahertz spectroscopy of an electron-hole bilayer system in AlN/GaN/AlN quantum wells

231 EDL 1.1-kV vertical GaN pn diodes with p-GaN regrown by molecular beam epitaxy

230 APL Single-crystal N-polar GaN p-n diodes by plasma-assisted molecular beam epitaxy

226 TED Design and realization of GaN trench junction-barrier-Schottky-diodes (JBSD)

224 APL Strained GaN Quantum-Well FETs on Single-Crystal Bulk AlN Substrates

2016

219 DRC First demonstration of strained AlN/GaN/AlN quantum well FETs on SiC

217 DRC Vertical Ga2O3Schottky barrier diodes on single-crystal β-Ga2O3(−201) substrates

216 DRC GaN tunnel switch diodes

214 APL Intrinsic electron mobility limits in beta-Ga2O3

205 EDL 1.7 kV and 0.55 mOhm.cm2 GaN p-n diodes on Bulk GaN substrates with Avalanche Capability

204 EDL Ultralow-Leakage AlGaN/GaN HEMTs on Si with Non-Alloyed Regrown Ohmic Contacts

2015

203 APL Near unity ideality factor and Shockley-Read_Hall lifetime in GaN-on-GaN p-n diodes with avalanche breakdown

201 DRC High-voltage polarization-induced vertical heterostructure p-n junction diodes on bulk GaN substrates

200 DRC Unique opportunity to harness polarization in GaN to override the conventional power electronics figure-of-merits

199 IEDM Steep subthreshold swing tunnel FETs: GaN/InN/GaN and transition metal dichalcogenide channels

198 APL High breakdown single-crystal GaN p-n diodes by molecular beam epitaxy

196 APL Polarization-induced Zener tunnel diodes in GaN/InGaN/GaN heterojunctions

192 JXCDS Transistor Switches using Active Piezoelectric Gate Barriers

191 JXCDS Polarization-Engineered III-Nitride Heterojunction Tunnel Field-Effect Transistors

189 JCG Low-temperature AlN growth by MBE and its application in HEMTs

187 EDL 1.9 kV AlGaN/GaN lateral Schottky barrier diodes on Silicon

2014

180 IEDM Sub 60mV/decade Steep Transistors with Compliant Piezoelectric Gate Barriers

179 DRC Characteristics of InAlN/AlN/GaN MOSHEMTs with steeper than 60 mV/decade sub-threshold slopes in the deep sub-threshold region

176 DRC GaN lateral PolarSJs: Polarization-doped super junctions

169 APEX Plasma-MBE growth conditions of AlGaN/GaN HEMTs on Silicon and their device characteristics with epitaxially regrown ohmic contacts

165 APL High-Voltage Field-Effect Transistors with Wide-Bandgap Ga2O3 Nanomembranes

163 EDL GaN Heterostructure Barrier Diodes (HBD) exploiting Polarization-induced Delta-doping

162 APL Two-dimensional electron gases in strained quantum wells for AlN/GaN/AlN double heterostructures FETs on AlN

159 APEX Impact of CF4 plasma treatment on threshold voltage and mobility in Al2O3/InAlN/GaN MOSHEMTs

157 Phys. Stat. Sol. AlGaN/GaN HEMTs on Silicon by MBE with regrown contacts and fT=153 GHz

156 APEX Performance enhancement of InAlN/GaN HEMTs by KOH surface treatment

155 TED Effect of Fringing Capacitances on the RF Performance of GaN HEMTs with T-Gates

2013

153 IEDM Dispersion- free operation in InAlN-based HEMTs with ultrathin or no passivation

150 Phys. Stat. Sol. On the possibility of sub 60 mV/decade subthreshold switching in piezoelectric gate barrier transistors

148 EDL Polarization-Induced GaN-on-Insulator E/D Mode p-Channel Heterostructure FETs

142 JJAP Ultrascaled InAlN/GaN HEMTs with fT of 400 GHz

138 IEEE Trans. THz Power amplification at THz via plasma wave excitation in RTD-gated HEMTs

137 APEX InGaN channel high electron mobility transistors with InAlGaN barrier and ft/fmax or 260/220 GHz

134 EDL Quaternary barrier InAlGaN HEMTs with ft/fmax of 230/300 GHz

131 Sol. St. Electronics Time-delay analysis in high-speed gate-recessed E-Mode InAlN HEMTs

2012

126 DRC A surface-potential based compact model for GaN HEMTs incorporating polarization charges

124 DRC Ultra-thin Body GaN-on-insulator nFETs and pFETs: Towards III-nitride complementary logic

123 DRC Monolithically integrated E/D-mode InAlN HEMTs with Æ’t/Æ’max > 200/220 GHz

122 APL Polarization effects on gate leakage in InAlN/AlN/GaN HEMTs

117 JAP Surface potential analysis of AlN/GaN heterostructures by electrochemical capacitance-voltage measurements

114 APL Ultra-low resistance ohmic contacts to GaN with high Si doping concentrations grown by molecular beam epitaxy

112 ECS Trans. Enhanced THz detection in Resonant Tunnel Diode-Gated HEMTs

110 EDL InAlN/AlN/GaN HEMTs with MBE-regrown contacts and fT=370 GHz

109 APL InGaN Channel High Electron Mobility Transistor Structures Grown by Metal Organic Chemical Vapor Deposition

108 EDL Effect of Optical Phonon Scattering on the Performance of GaN Transistors

107 EDL Ultra thin GaN-on-Insulator Quantum Well FETs with Regrown MBE Contacts Â

106 EDL MBE regrown ohmics in In0.17AlN HEMTs with regrowth interface resistance of 0.05 ohm-mm

2011

98 DRC Barrier height, interface charge & tunneling effective mass in ALD Al2O3/AlN/GaN HEMTs

97 DRC Improvement of fT in InAIGaN barrier HEMTs by Plasma Treatment

95 ECS Trans. The resurgence of III-Nitride materials development: AlInN HEMTs and GaN-on-Si

93 APL Presence and origin of interface charges at atomic-layer deposited Al2O3/III-nitride heterojunctions

89 APEX Si-containing Recessed Ohmic Contacts and 210 GHz Quaternary Barrier InAlGaN High-Electron-Mobility Transistors

84 EDL 220 GHz Quaternary Barrier InAlGaN/AlN/GaN HEMTs

82 EDL 210 GHz InAlN HEMTs with dielectric-free passivation

81 Phys. Stat. Sol. Subcritical Barrier AlN/GaN E/D-Mode HFETs and Inverters

80 Phys. Stat. Sol. Metal-Face InAlN/AlN/GaN HEMTs with regrown Ohmic contacts by Molecular Beam Epitaxy

79 Phys. Stat. Sol. Polarization Engineering in Group-III Nitride Heterostructures: New Opportunities for Device Design

78 JCG MBE growth of high conductivity single and multiple AlN/GaN heterojunctions

76 EDL Enhancement-Mode InAlN/AlN/GaN HEMTs with 10-12A/mm leakage current and 1012 on/off current ratio

2010

74 APL High mobility two-dimensional electron gases in nitride heterostructures with high Al composition AlGaN alloy barriers

73 IEDM High-performance monolithically-integrated E/D mode InAlN/AlN/GaN HEMTs for mixed-signal applications

72 DRC Work-Function Engineering in Novel High AI Composition Al0.72Ga0.28N/AIN/GaN HEMTs

71 DRC High Performance E-mode InAIN/GaN HEMTs: Interface States from Subthreshold Slopes

69 APL Polarization-mediated remote surface roughness scattering in ultrathin barrier GaN high-electron mobility transistors

67 EDL Gate-recessed Enhancement-Mode InAlN/AlN/GaN HEMTs with 1.9 A/mm Drain Current Density and 800 mS/mm Transconductance

65 EDL Threshold Voltage Control in Al0.72Ga0.28N/AlN/GaN HEMTs by Work-Function Engineering

64 Phys. Stat. Sol. Short-period AlN/GaN p-type superlattices: Hole transport usage in p-n Junctions

61 APL Polarization-engineered removal of buffer leakage for GaN Transistors

60 Science Polarization Induced Hole Doping in Wide Bandgap Uniaxial Semiconductor Heterostructures

2009

59 Phys. Rev. Lett. Polarization Induced Zener Tunnel Junctions in Wide Bandgap Heterostructures

58 DRC Top-Down AlN/GaN Enhancement- & Depletion-mode Nanoribbon HEMTs

2008

44 APL Stokes and anti-Stokes resonant Raman scattering from biased AlN/GaN heterostructures

43 APL Isotope disorder of phonons in GaN and its beneficial effect in high power field effect transistors

42 EDL AlN/GaN insulated gate HEMTs with 2.3 A/mm output current and 480 mS/mm transconductance

36 APL Very Low Sheet Resistance and Shubnikov de-Haas Oscillations in Two-Dimensional Electron Gases at Ultrathin Binary AlN/GaN Heterojunctions

34 APL Evidence of hot electrons generated from an AlN/GaN HEMT

2007

33 APL Hot phonon effect on electron velocity saturation in GaN: A second look

30 ECS Trans. MBE-grown Ultra-Shallow AlN/GaN HFET Technology

26 APL A High-Mobility Window for Two-Dimensional Electron Gases at Ultrathin AlN/GaN Heterojunctions

2006

15 J. Electr. Mat. Ultrathin CdSe Nanowire FETs and their Optical Properties

2004

12 APL AlGaN/GaN polarization-doped field-effect transistor for microwave power applications

2003

10 EDL Explanation of anomalously high β in GaN-based bipolar transistors

2002

7 DRC p-GaN/AlGaN/GaN High Electron Mobility Transistors

6 APL Realization of wide electron slabs by polarization bulk doping in graded III-V nitride semiconductor alloys

5 EDL Effect of p-doped overlayer thickness on RF-dispersion in GaN JFETs