1. Ultra-wide bandgap semiconductor β-Ga2O3 for power electronics applications
Hong Zhou, Jinhyun Noh, and Peide D. Ye
Motivation
Depletion/Enhancement-mode GOOI FET
Thickness Dependent VT
β-Ga2O3 has an ultra-wide bandgap of 4.8 eV, high electrical field (Ebr) of 8 MV/cm, high electron mobility of 300 cm2/Vs, and high Bliga’s FOM of 3444, showing its great promise to replace GaN and SiC as next generation power device semiconductor.
β-Ga2O3 on insulator field-effect transistors (GOOI FETs) is a good approach to increase BV and reduce self-heating effect by incorporating a wider bandgap and higher thermal conductivity substrate.
Device Schematics and Ohmic Contact Optimization
VT is shifted from negative to positive when thickness is reduced.
BV Measurement and Simulation
Record high ID of 1.5/1.0 A/mm for D/E-modes GOOI FETs. High on/off ratio of 1010 and low SS of 150~160 mV/dec are demonstrated.
Device schematic of GOOI FET with β-Ga2O3 nano-membrane surface roughness of 0.3 nm.
Performance Benchmark of GOOI FET
High BV=185 V is achieved for a short LSD=0.9 μm device and an average E=2 MV/cm is demonstrated.
Conclusions
D/E-modes GOOI FETs have demonstrated the highest IDMAX of 1.5/1 A/mm, which are 1~2 orders higher than other β-Ga2O3 FETs.
E-mode GOOI FETs can be achieved by simply shrinking β-Ga2O3 thickness and an average Ebr =2 MV/cm is demonstrated.
Acknowledgement
The authors would like to thank the technical help from AFRL.
References
30 s Ar plasma treated contact turns out to be with lowest Rc. Ar plasma untreated or over treated contacts lead to Schottky-behavior contact.
W. S. Hwang, et al., Appl. Phys. Lett.,vol. 104, , 2014.
H. Zhou et al., IEEE EDL, vol. 38, , 2017.
D/E-mode GOOI FETs present 1~2 order higher IDMAX.
NEEDS Annual Review: May 8-9, 2017