6H-SiC P+ PN+ junction diodes are fabricated and the forward current density-voltage (J-V) characteristics are compared with identical P+ NN+ diodes in a temperature range of room temperature to 300 degreesC. While the room temperature I-V characteristics of P+ NN+ diodes are more or less linear after turn-on at similar to 10 A/cm(2), the I-V characteristics of P+ PN+ diodes show a non-linear behavior (self-adjusting emitting efficiency) even after turn-on, indicating a variation in the on-state resistance with increase in forward current. Results have shown that P+ PN+ diodes exhibit higher forward current density compared to P+ NN+ diodes on 6H-SiC after a certain forward bias. The superior forward performance on P+ PN+ diode is attributed to the high injection efficiency and low carrier recombination. The forward performance of P+ PN+ diodes with an ideal ohmic contact structure is also investigated.