LONG WAVELENGTH OPTIC DETECTOR OF AVALANCHE PHOTO DIODE TYPE

摘要

In the avalanche photodiode type long-wavelength photodetector, an InGaAsP layer formed by In _0.52 Al _0.48 As having a lattice match to an InP substrate of the amplification layer and having an energy bandgap larger than the InP, and having a small energy bandgap or After exposing the InGaAs layer to the outside, the energy band gap is larger than the InGaAsP layer or InGaAs layer, and In _0.52 Al _0.48 As, which is lattice matched to InP, is used as the window layer, and the band gap is an amplification layer (In _0.52 Al _0.48 As). A quaternary p-In _0.72 Ga _0.28 As _0.61 P _0.39 layer, which is intermediate between the absorbing layer (In _0.53 Ga _0.47 As), is formed between the amplifying layer and the absorbing layer to reduce the strength of the electric field applied to the absorbing layer, thereby reducing tunneling leakage. It prevents the generation of current and at the same time prevents the accumulation of charges at the interface between the amplification layer and the absorption layer due to the band gap difference, increasing the operation speed and increasing the breakdown voltage. .