Geiger-mode photodiode with integrated and adjustable quenching resistor, photodiode array, and manufacturing method thereof

An array including a plurality of photodiodes, each photodiode comprising:

• a body of semiconductor material having a first conductivity type, a first surface and a second surface;
• a trench extending through said body from said first surface and surrounding an active region;
• a lateral-isolation region within the trench, said isolation region comprising a conductive region and an insulating region of dielectric material, which surrounds said conductive region;
• and
• an anode region having a second conductivity type, extending within said active region and facing said first surface, said active region forming a cathode region extending between said anode region and the second surface and defining a vertical quenching resistor;
• and
• a contact region of conductive material, overlying said first surface and in direct contact with said conductive region, and configured to be electrically connected to an external biasing circuit biasing the conductive region at a gate voltage such as to create a depletion region in said active region around said insulating region, thus varying the resistance of said quenching resistor.

A photon-detection system comprising:

• a processing unit;
• an array including a plurality of photodiodes, each photodiode comprising:
• a body of semiconductor material having a first conductivity type, a first surface and a second surface;
• a trench extending through said body from said first surface and surrounding an active region;
• a lateral-isolation region within the trench, said isolation region comprising a conductive region and an insulating region of dielectric material, which surrounds said conductive region;
• and
• an anode region having a second conductivity type, extending within said active region and facing said first surface, said active region forming a cathode region extending between said anode region and the second surface and defining a vertical quenching resistor;
• and
• a contact region of conductive material, overlying said first surface and in direct contact with said conductive region, and configured to be electrically connected to an external biasing circuit biasing the conductive region at a gate voltage such as to create a depletion region in said active region around said insulating region, thus varying the resistance of said quenching resistor;
• the photon-detection system further comprising a power supply coupled to said processing unit and to said array.

A method for manufacturing a Geiger-mode avalanche photodiode, comprising the steps of:

• forming a body of semiconductor material having with a first conductivity type, a first surface and a second surface;
• forming, within said body, a trench extending from said first surface;
• forming an insulating region of dielectric material within the trench;
• filling said trench with a conductive region surrounded by the insulating region so as to form a lateral-isolation region delimiting, in said body, an active region;
• and
• forming, within the active region, an anode region having a second conductivity type and facing said first surface, a cathode region extending in said active region between said anode region and the second surface and defining a vertical quenching resistor;
• forming a contact region of conductive material on said first surface and in direct contact with said conductive region.

A diode, comprising:

• semiconductor region having first and second opposite surfaces;
• an anode disposed in the semiconductor region adjacent to the first surface;
• a cathode disposed in the semiconductor region adjacent to the second surface;
• an impedance disposed in the semiconductor region between the anode and the cathode;
• a conductive gate disposed in the semiconductor region adjacent to the impedance;
• and
• a gate insulator disposed in the semiconductor region between the impedance and the gate.

A pixel array, comprising:

• a semiconductor region having a light receiving first surface and a second surface opposite to the first surface;
• and
• pixel sensors disposed in the region, at least one of the sensors including:
• an acceptor type region adjacent to the first surface;
• a donor type region adjacent to the second surface;
• an impedance disposed between the acceptor and donor type regions;
• a conductive gate disposed adjacent to the impedance;
• and
• a gate insulator disposed between the impedance and the gate.

A system, comprising:

• a pixel array, comprising:
• a semiconductor region having a light receiving first surface and a second surface opposite to the first surface;
• and
• pixel sensors disposed in the region, at least one of the sensors including:
• an acceptor type region adjacent to the first surface;
• a donor type region adjacent to the second surface;
• an impedance disposed between the acceptor and donor type regions;
• a conductive gate disposed adjacent to the impedance;
• and
• a gate insulator disposed between the impedance and the gate;
• and
• a controller coupled to the pixel array.