Investigation of SOI Substrates Incorporated with Buried MoSi2 for High Frequency SiGe HBTs

Highly arsenic-doped Si-on-insulator (SOI) substrate incorporated with buried MoSi2 layers is fabricated aiming at decreasing the collector series resistance of SiGe heterojunction bipolar transistors (HBTs) on SOI, thereby enhancing cutoff frequency (fT) performance and increasing the maximum value of fT (fTMAX). The fT performance at medium current is enhanced and current required for fT=15GHz is reduced by half. The value of fTMAX is improved by 30%.