Patent ID: 7834379
Filing Date: 2010-11-16
Classification: H01L,Y02E

Abstract:
1. A separate absorption and multiplication structure avalanche photodiode (SAM-APD) comprising: an epitaxial layer structure grown on an n-doped substrate in order as follows: an n-doped buffer layer; an unintentionally doped absorption layer; a grading layer; an n-doped field control layer; an unintentionally doped multiplication layer, including a diffused p-n junction having a diffusion profile and an active region comprising a diffusion region in the multiplication layer; and a solid source material layer; the device further comprising: a p-contact applied in electrical contact with the active region; a light input window; and an n-contact in electrical contact with the n-doped substrate, wherein the active region comprises an edge zone, an intermediate zone and a central zone arranged concentrically in monotonically increasing depth, and wherein the intermediate zone has a diameter approximately matching a diameter of the solid source material layer, such that the diffusion profile of the p-n junction comprises a smooth edge transition for suppressing edge breakdown.