RF Performance of <italic>In Situ</italic> SiN<italic>x</italic>Gate Dielectric AlGaN/GaN MISHEMT on 6-in Silicon-on-Insulator Substrate

Abstract

A high power-added efficiency and low dynamic on-resistance ( $R_{ \mathrm{\scriptscriptstyle ON}})$ AlGaN/GaN metal–insulator–semiconductor high-electron mobility transistor (MISHEMT) with in situ SiN x insulator design was demonstrated on 150-mm silicon-on-insulator (SOI) substrate. Compared to traditional high-resistivity Si substrate, SiN x /AlGaN/GaN MISHEMT grown on the SOI 5- $\mu \text{m}$ -thick Si active layer performed better tensile stress relaxation and surface flatness. Based on Hall measurement results, electron mobility and the sheet charge density on SOI substrate were improved simultaneously owing to a lower-defect density which is also proofed by pulse measurement and low-frequency noise measurement. Due to the low-feedback substrate capacitance, the bandwidth, and the linearity were also improved simultaneously by SOI substrate design.