Fully Planar 4H-SiC Avalanche Photodiode With Low Breakdown Voltage

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.