FULLY DEPLETED DIODE PASSIVATION ACTIVE PASSIVATION ARCHITECTURE

摘要

A fully depleted “diode passivation active passivation architecture” (DPAPA) produces a photodiode structure which includes a substrate, a highly-doped buffer layer of a first carrier doping type above the substrate, a low-doped or undoped semiconductor active layer of the first carrier doping type above the buffer layer, a low-doped or undoped passivation layer above the active layer, the passivation layer having a wider band gap than the active layer; and a junction layer of a carrier doping type opposite the first carrier doping type above the passivation layer such that a pn junction is formed between the junction layer and the passivation and active layers, the junction creating a depletion region which expands completely through the passivation and active layers in response to a reverse bias voltage. The fully depleted structure substantially eliminates Auger recombination, reduces dark currents and enables cryogenic level performance at high temperatures.

主权项

1. A photodiode structure, comprising:
a substrate; a first passivating buffer layer of a first carrier doping type (n or p) and which is highly-doped through part or all of its thickness above said substrate; a low-doped or undoped semiconductor active layer of said first carrier doping type above said buffer layer; a low-doped or undoped second passivation layer above said active layer, said second passivation layer having a band gap energy graded over at least part of its thickness from that of the active layer to a larger energy; and a junction layer of a second carrier doping type (p or n) opposite said first carrier doping type and directly above said second passivation layer such that a pn junction is formed between said junction layer and said second passivation and active layers, said junction creating a depletion region which expands through at least said second passivation layer and said active layer in response to a reverse bias voltage; and an electrical contact with said first passivating buffer layer such that said buffer layer provides a return current path to said contact.