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 transistors (JFET's) were characterized from 25 degrees C to 350 degrees C in terms of transconductance (g(m)), pinchoff voltage (V-p), output resistance (r(o)), input resistance (R(in)), drain-to-source current at zero gate-to-source voltage (I-DSS), gate-to-source reverse biased leakage 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 to 500 degrees C) fabricated at Auburn University for use in numerous industrial applications. Simulation program with integrated circuit emphasis (SPICE) simulations of the temperature monitoring circuit's output voltage corresponded well with measured data as a function of temperature. Linear regression (LR) analysis of measured data revealed a notably 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 temperature. Below -50 degrees C, the output became nonlinear, presumably from carrier freeze-out effects. To the best of our knowledge, this represents the first successful implementation of SiC active devices into a temperature sensor which demonstrated stable operation up to 500 degrees C.