AVALANCHE PHOTODIODE

摘要

An object is to provide an electron injected APD with an embedded n electrode structure in which edge breakdown can be suppressed without controlling the doping profile of an n-type region of the embedded n electrode structure with high precision. In the APD according to the present invention, a buffer layer 33 with a low ionization rate is inserted between an n electrode connecting layer 32 and an avalanche multiplication layer 34. Specifically, the APD is an electron injected APD in which an n electrode layer 31, the n electrode connecting layer 32, the buffer layer 33, the avalanche multiplication layer 34, an electric field control layer 35, a band gap gradient layer 36, a low-concentration light absorbing layer 37a, a p-type light absorbing layer 37b, and a p electrode layer 38 are sequentially stacked, and a light absorbing portion 37 that includes at least the low-concentration light absorbing layer 37a and the p-type light absorbing layer 37b forms a mesa shape.