Patent ID: 9065002
Filing Date: 2015-06-23
Classification: G01S,H01L,Y02E

Abstract:
1. A single photon avalanche diode (SPAD) device, comprising: a substrate doped to exhibit a first type conductivity and having a top substrate surface and a bottom substrate surface, the first type conductivity being either one of a n-type conductivity and an opposite p-type conductivity; a well region located in the substrate from the top substrate surface and doped to exhibit a second, opposite type conductivity to leave a substrate region of the first type conductivity in the substrate between the well region and the bottom substrate surface, wherein the bottom of the well region and the top of the substrate region interfaces to form a deep p-n junction; a trench ring formed in the well region to create a trench from the top substrate surface that surrounds a first portion of the well region and leave a second portion of the well region outside the trench ring, the trench ring filled with an insulator material to form a guard ring to spatially confine the first portion of the well region; and a shallow region in the first portion of the well region inside the guard ring that is doped to exhibit the first type conductivity to have a depth from the top substrate surface less than a depth of the guard ring, a bottom part of the shallow region interfacing with a remaining of the first portion of the well region in the second type conductivity to form a shallow p-n junction.