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_0.18Al_0.82N/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 ~10⁷ 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.