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