SiC Lateral Trench JFET for Harsh-Environment Wireless Systems

Abstract

SiC Lateral Trench JFET (LTJFET) technology is demonstrated as a promising candidate for use in high-temperature wireless telemetry systems. 4H-SiC LTJFETs were designed, fabricated and characterized for DC, and small-signal AC and RF performance at different case temperatures. Four-fold drain current reduction was observed at 460°C as compared to RT measurements. The measured threshold voltage shift was less than 2.3 mV/°C from 21°C to 460°C. A simple common source amplifier built using a fabricated device demonstrated stable small-signal AC performance after 100 hrs of operation at 450°C. Small-signal RF measurements were carried out on the packaged devices at different temperatures. GMax above 8 dB was measured over the L-band frequency range at RT. The average degradation of small-signal power gain measured at f=250 MHz did not exceed 0.0125 dB/ °C over the temperature ranging from 21°C to 365°C.