The a-SiC/c-Si(n) Isotype Heterojunction as a High Sensitivity Temperature Sensor

The a-SiC/c-Si(n) isotype heterojunction has been studiedas a temperature sensor by measuring its reverse current-voltage(IR−V) and reverse voltage-temperature (V-T)characteristics, as well as its reverse current temperaturedependence. The IR−V characteristics exhibit an almost constantcurrent, whereas the reverse current IR depends strongly on T(from 230 K up to 320K). The V-T characteristics, atdifferent reverse currents, reveal a highly temperature sensitivebehavior for the a-SiC/c-Si(n) junction. The measuredvalues of temperature sensitivity (Δ V/ΔT)max was found to be(≅−2.5 V/K) in the moderate temperature range, which aremuch higher than those obtained with bulk semiconductortemperature sensors. The high sensitivity-temperature- range ofthe a-SiC/c-Si(n) heterojunctions can be controlledelectrically within the regim of values from 230 K up to 320 K.Finally, the high sensitivity of these devices, in conjunctionwith the fact that a-SiC films can be used as an add-on to theexisting Si technology, emerge new possibilities to thefabrication of high sensitivity temperature microsensors