Self-aligned inversion-channel In0.75Ga0.25As MOSFETs using MBE-Al2O3/Ga2O3(Gd2O3) and ALD-Al2O3 as gate dielectrics

High-performance self-aligned inversion-channel In0.75Ga0.25As n-MOSFETs using in-situ ultra-high-vacuum (UHV) deposited Al2O3/Ga2O3(Gd2O3) and ex-situ atomic-layer-deposited (ALD) Al2O3 as gate dielectrics have been fabricated. Both devices exhibit excellent DC characteristics, including high drain currents and transconductances. A 1.2µm-gate-length In0.75Ga0.25As MOSFET using Al2O3(2nm-thick)/GGO(13nm-thick) dual-layer gate dielectric demonstrated a maximum drain current of 970 µA/µm, a peak transconductance of 410 µS/µm, and a peak mobility of 1560 cm²/V·s. A maximum drain current of 194 µA/µm and a peak transconductance of 126 µS/µm were exhibited by a 2µm-gate-length In0.75Ga0.25As MOSFET using ALD-Al2O3(6nm-thick).