High-Voltage CMOS Compatible SOI MESFET Characterization and Spice Model Extraction

A mature and well-established SOI CMOS process has been used to fabricate metal-semiconductor field-effect transistors (MESFETs) that operate in the gigahertz range. These 0.6mum depletion-mode SOI MESFETs exhibit a maximum breakdown voltage of 45V in spite of being fabricated using the standard 3.3V CMOS process. This high voltage capability makes the device a strong contender for applications such as power amplifiers, voltage controlled oscillators and DC-DC converters. DC and RF characterization involving breakdown voltage measurements, S-parameter measurements and small-signal parameter extraction was conducted on the device. We have customized an advanced, commercially available TOM3 SPICE MESFET model to represent the SOI MESFET. Based on extracted small-signal parameters, a simplified method to extract the charge parameters of the TOM3 capacitance model was developed. A diode subcircuit has been proposed to model the breakdown mechanism in the SOI MESFET