Comparison of current-voltage characteristics of n- and p-type 6H-SiC Schottky diodes

Current-voltage (I-V) characteristics of n- and p-type 6H-SiC Schottky diod es are compared in a temperature range of room temperature to 400 degreesC. While the room temperature I-V characteristics of the n-type Schottky diod e after turn-on is more or less linear up to similar to 100 A/cm(2), the T- V characteristics of the p-type Schottky diode shows a non-linear behavior even after turn-on, indicating a variation in the on-state resistance with increase in forward current. For the first time it is shown that at high cu rrent densities (>125 A/cm(2)) the forward voltage drop across p-type Schot tky diodes is lower than that across n-type Schottky diodes on 6H-SiC. High temperature measurements indicate that while the on-state resistance of n- type Schottky diodes increases with increase in temperature, the on-state r esistance of p-type Schottky diodes decreases with increase in temperature up to similar to 330 K.