Planar guarded avalanche diodes in InP fabricated by ion implantation

Abstract

Planar guarded avalanche diodes in InP have been fabricated using a double‐ion‐implantation technique. Silicon was selectively implanted into an n‐type epitaxial layer to increase the concentration portion of the diode, and beryllium was implanted to form the p‐n junction. When appropriately reverse biased, these diodes exhibited uniform avalanche photocurrent gain in the central portion, where the electric field is maximum. With a 1‐kΩ load, photoresponse gains as high as 20 were measured, although values of 6 to 8 were more typical. At present, the external photoresponse gain with a fixed load is limited by the shunting effect of the diode’s differential resistance.