High-Gain InAs Planar Avalanche Photodiodes

We report the fabrication of InAs planar avalanche photodiodes (APDs) using Be ion implantation. The planar APDs have a low background doping of 2 × 10
¹⁴
cm
^-3
and large depletion widths approaching 8 μm. The thick depletion width enabled a gain of 330 to be achieved at -26 V at 200 K without inducing a significant tunneling current. No edge breakdown was observed within the APDs. The surface leakage current was found to be low with a gain normalized dark current density of 400 μAcm
^-2
at -20 V at 200 K.