Study on effect of back oxide thickness variation in FDSOI MOSFET on analogue circuit performance

Abstract

In this study, the analogue performance of radio-frequency (RF) range amplifiers and ring oscillators designed using fully depleted silicon on insulator (FDSOI) metal–oxide–semiconductor field-effect transistors (MOSFETs) is studied for different back oxide (BOX) thickness. The analysis exemplifies the need for BOX thickness variation analysis for the superior analogue/RF performance. The analogue parameters of the circuit analysed for different BOX thickness are the bandwidth, the linearity and the power consumption. The study shows that for an FDSOI MOSFET-based amplifier circuit, with increasing BOX thickness the bandwidth increases and the gain decreases. Also an optimum value of gain–bandwidth product for the amplifier is proposed considering the BOX thickness and the gate length of the device. It is also shown that frequency of oscillation for the ring oscillators increases with increasing BOX thickness.