High Temperature High Current Gain IC Compatible 4H-SiC Phototransistor

This paper presents our in-house fabricated 4H-SiC n-p-n phototransistors. The wafer mapping of the phototransistor on two wafers shows a mean maximum forward current gain (βFmax) of 100 at 25 °C. The phototransistor with the highest βFmax of 113 has been characterized from room temperature to 500 °C. βFmax drops to 51 at 400 °C and remains the same at 500 °C. The photocurrent gain of the phototransistor is 3.9 at 25 °C and increases to 14 at 500 °C under the 365 nm UV light with the optical power of 0.31 mW. The processing of the phototransistor is same to our 4H-SiC-based bipolar integrated circuits, so it is a promising candidate for 4H-SiC opto-electronics on-chip integration.