Array of mutually insulated Geiger-mode avalanche photodiodes, and corresponding manufacturing process

A process for manufacturing an array of Geiger-mode avalanche photodiodes, comprising the steps of:

• forming a body of semiconductor material having a first conductivity type, and a surface;
• forming, inside said body and facing said surface, a first cathode region having the second conductivity type;
• forming inside said body and facing said surface, an anode region having the first conductivity type and a higher doping level than said body, said anode region extending laterally and at a distance from said first cathode region;
• and
• forming, inside said body, an insulation region comprising forming a mirror region of metal material, said insulation region extending through said body and surrounding an active area from the rest of the body, the active area housing the first cathode region and the anode region,
• wherein the step of forming said insulation region further comprises introducing dopant species of said second conductivity type around the mirror region so as to form a channel-stopper region surrounding said mirror region;
• the method further comprising the steps of forming a first dielectric layer on said surface of said body so as to cover a portion of said active area and delimit an opening overlying said active area;
• forming a polycrystalline region extending at least within said opening and transferring dopant ion species from the polycrystalline region to the active area so as to form said first cathode region underneath said opening.

A process for manufacturing an array of Geiger-mode avalanche photodiodes, comprising the steps of:

• forming a body of semiconductor material having a first conductivity type, and a surface;
• forming, inside said body and facing said surface, a first cathode region having the second conductivity type;
• forming inside said body and facing said surface, an anode region having the first conductivity type and a higher doping level than said body, said anode region extending laterally and at a distance from said first cathode region;
• and
• forming, inside said body, an insulation region comprising forming a mirror region of metal material, said insulation region extending through said body and surrounding an active area from the rest of the body, the active area housing the first cathode region and the anode region,
• wherein the step of forming said insulation region further comprises introducing dopant species of said second conductivity type around the mirror region so as to form a channel-stopper region surrounding said mirror region;
• the method further comprising introducing dopant ion species of the first conductivity type into said active area underneath the first cathode region so as to form an enrichment region underneath and in direct contact with the first cathode region, said enrichment region having the first conductivity type and a higher doping level than said active area.

A method, comprising:

• forming an anode adjacent to a surface of a semiconductor material;
• forming a first portion of a cathode in the semiconductor material adjacent to the surface and remote from the anode;
• forming in the semiconductor material between the anode and the cathode a body having a same conductivity as the anode;
• forming a trench in the semiconductor material having a trench side wall doped with a conductivity opposite to the conductivity of the body;
• and
• forming an isolator in the semiconductor material in the trench around the cathode and the anode having a mirror region made of metal material surrounded by a channel-stopper region.

A method, comprising:

• forming an anode adjacent to a surface of a semiconductor material;
• forming a first portion of a cathode in the semiconductor material adjacent to the surface and remote from the anode;
• forming in the semiconductor material between the anode and the cathode a body having a same conductivity as the anode;
• and
• forming an isolator in the semiconductor material around the cathode and the anode;
• wherein forming the isolator comprises:
• forming a trench in the semiconductor material adjacent to the body;
• doping a wall of the trench to have a conductivity opposite to the conductivity of the body;
• lining the wall of the trench with an insulator;
• and
• forming a reflective material in the lined trench.