A HYBRID GH-SIC TEMPERATURE SENSOR OPERATIONAL FROM 25-DEGREES-C TO 500-DEGREES-C

6H-SiC buried-gate n-channel depletion-mode junction field-effect tran sistors (JFET's) were characterized from 25 degrees C to 350 degrees C in terms of transconductance (g(m)), pinchoff voltage (V-p), output r esistance (r(o)), input resistance (R(in)), drain-to-source current at zero gate-to-source voltage (I-DSS), gate-to-source reverse biased le akage current (I-GSS), off-state drain-to-source current (I-DSS(off)), and noise power spectral density (S-V) The 6H-SiC JFET's were used in a hybrid temperature monitoring circuit (tested from -196 degrees C t o 500 degrees C) fabricated at Auburn University for use in numerous i ndustrial applications. Simulation program with integrated circuit emp hasis (SPICE) simulations of the temperature monitoring circuit's outp ut voltage corresponded well with measured data as a function of tempe rature. Linear regression (LR) analysis of measured data revealed a no tably sensitive (similar to 2.3 mV/degrees), and an eminently linear ( correlation coefficient = -0.9996G... over 25 degrees C to 500 degrees C range) relationship between the measured output voltage and tempera ture. Below -50 degrees C, the output became nonlinear, presumably fro m carrier freeze-out effects. To the best of our knowledge, this repre sents the first successful implementation of SiC active devices into a temperature sensor which demonstrated stable operation up to 500 degr ees C.