We report on the structure and performance of 4H-SiC p + -n APDs fabricated in a fully planar technology. A dark current density lower than 10 nA/cm 2 at 30-V reverse bias and a breakdown voltage of 88 V were observed. A gain as high as 10 5 was measured at 94-V reverse bias, confirming the avalanche multiplication working condition. The maximum responsivity value was measured at 270 nm, increasing from 0.06 A/W (QE = 29%) at 0-V bias to 0.10 A/W (QE of about 45%) at 30-V reverse bias.