InAlN/GaN MOSHEMTs with high drain current of 2.3 A/mm high on/off ratio of 1012 and low SS of 64 mV/dec enabled by atomic-layer-epitaxial MgCaO as gate dielectric

Abstract

Summary form only given. Recently, GaN-based high-electron-mobility-transistor (HEMT) has demonstrated its promise in high frequency, high power and low noise electronic devices. The lattice matched InAlN/GaN HEMT structure provides a higher 2D electron density than AlGaN/GaN due to a larger bandgap offset and minimized short-channel-effects due to its thinner barrier. However, because of its several-nm thin barrier, those devices usually suffer from high gate leakage and interface trap issues, the device off-state performance is degraded and thereby the off-state breakdown voltage is decreased. Therefore, finding a good method to reduce the gate leakage and interface trap density is of great importance to improve the device off-state performance. In this study, we use atomic layer epitaxial MgCaO as gate dielectric to fabricate sub-100nm InAlN/GaN MOSHEMTs with significantly improved maximum drain current, current on/off ratio and low subthreshold swing.