Impact of Silicon-on-Insulator Substrate Parameters on the Radio Frequency Performance of Quasi-Silicon-on-Insulator Power Metal-Oxide-Semiconductor Field Effect Transistors

Abstract

We have investigated the impact of silicon-on-insulator (SOI) substrate parameters on the radio-frequency performance of quasi-SOI power metal–oxide–semiconductor field effect transistors (MOSFETs) to optimize the device structure. We found that increasing the top silicon layer thickness of the quasi-SOI power MOSFET increased the breakdown voltage and decreased the on-resistance. Increasing the thickness of the top Si layer also increased the cutoff frequency, the maximum oscillation frequency, and the power-added efficiency. The power-added efficiency of a quasi-SOI power MOSFET with a thick buried oxide layer was also higher than that of one with a thinner layer because the thicker buried oxide resulted in lower source-to-drain capacitance, which enables better second-harmonic tuning.