Low noise avalanche photodiode having an avalanche multiplication layer of InAlAs/InGaAlAs

摘要

An avalanche photodiode includes an avalanche multiplication layer including a superlattice structure consisting of a plurality of barrier and well layers both lattice matched to InP such that the plurality of barrier and well layers are alternately provided one layer on the other layer. The barrier layers consist of InAlAs and the well layers consist of InCaAlAs quarternary system mixed crystal having a forbidden width smaller than 1 eV.