A model for reach‐through avalanche photodiodes (RAPD’s)

A model for silicon RAPD’s, which have an n+–p–π‐p+ structure and are fabricated by using the ion‐implantation techniques for forming the p layer, is studied. Useful relations for both an excess noise factor and a temperature dependence of an avalanche breakdown voltage are derived and are found to be in good agreement with experiments. The diodes discussed are useful in optical communication systems because of a relatively low operating voltage for the higher quantum efficiency.