500 $^{\circ}{\rm C}$ Bipolar Integrated OR/NOR Gate in 4H-SiC

Successful operation of low-voltage 4H-SiC n-p-n bipolar transistors and digital integrated circuits based on emitter coupled logic is reported from -40 °C to 500 °C. Nonmonotonous temperature dependence (previously predicted by simulations but now measured) was observed for the transistor current gain; in the range -40 °C-300 °C it decreased when the temperature increased, while it increased in the range 300 °C-500 °C. Stable noise margins of ~ 1 V were measured for a 2-input OR/NOR gate operated on -15 V supply voltage from 0 °C to 500 °C for both OR and NOR output.