Characterization of 4H-SiC JFETs for use in analog amplifiers capable of 723K operation

Discrete, buried-gate 4H-SiC JFETs (W/L = 1 mm/5 mu m) were packaged and characterized at temperatures ranging from 290 K to 773 K for use in a hybrid, 4H-SiC analog amplifier. A contaminated passivation oxide was found to limit high-temperature operation initially, but upon removal of the passivation layer the devices demonstrated stable operation to 773 K with adequate amplification (A(V) greater than 200 V/V) up to 673 K. From the 16 devices tested, a peak extrinsic Saturated transconductance (g(msat)) of 27.1 mS/mm was measured at 308 K, corresponding to a channel mobility of 400 cm(2)/V . s, excluding significant series resistance effects.