Indium-Based Ternary Barrier High-Electron- Mobility Transistors on Si Substrate With High ON/OFF Ratio for Power Applications

Indium-based ternary barrier high-electron-mobility transistors (HEMTs) directly on Si substrate is demonstrated in this letter with structure of In
_0.18
Al
_0.82
N/AlN/GaN-on-Si for high-power applications. The advantages of direct deposition on Si, compared with SiC or sapphire substrates, are high thermal dissipation and lower cost. The proposed InAlN barrier HEMTs exhibit a high ON/OFF ratio of ~10
⁷
and a steep subthreshold swing of 67 mV/dec. I
_Dsat
is measured to be 163 mA/mm, V
_DS
= 10 V, and V
_G
= 2 V with L
_G
= 2 μm. Material analysis using high-resolution X-ray diffraction and relaxation by reciprocal space mapping are also performed to confirm the indium barrier composition and epitaxy quality.