Indium-based ternary-barrier high-electron-mobility transistors (HEMT) directly on Si substrate are demonstrated in this work, using a structure of In0.18Al0.82N/AlN/GaN-on-Si for high-power applications. The advantages of HEMTs on Si substrates are the low cost and high throughput, which are beneficial for large wafer scale. The thermal dissipation of Si occurs between SiC and the sapphire substrate. The proposed InAlN-barrier HEMTs exhibit a high ON/OFF ratio with >7 orders of magnitudes and an excellent subthreshold swing (SS) below 100 mV/dec, owing to high polarization and less lattice mismatch with GaN. The IDsat is measured to be 163 mA/mm at VDS = 10 V and VG = 2 V with LG = 2 μm. When compared with the control InAlN/AlN/GaN-on-Si MIS-HEMTs with Ohmic contacts, the OFF current is reduced by one order magnitude when using the Schottky-drain contact technology.
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