Low noise geiger-mode avalanche photodiode and manufacturing process

A Geiger-mode avalanche photodiode, comprising:

• a substrate including a first surface and a second surface opposite to the first surface;
• a plurality of stacked epitaxial layers on the first surface, the plurality of epitaxial layers having a first conductivity type, the plurality of epitaxial layers includes a front epitaxial layer includes a third surface that is exposed from the plurality of stacked epitaxial layers;
• an anode region with a second conductivity type different to the first conductivity type within the front epitaxial layer and exposed at the third surface of the front epitaxial layer;
• a first dielectric layer on the third surface of the front epitaxial layer;
• a recess extending into and through the first dielectric layer exposing the anode region;
• an intermediate layer within the recess, on the first dielectric layer, and on the anode region;
• a second dielectric layer on the first dielectric layer, the intermediate layer, and the third surface of the epitaxial layer, the second dielectric layer is within the recess, and the second dielectric layer has the second conductivity type;
• and
• an anode metallization extending into and through the second dielectric layer to the intermediate layer, and the anode metallization is in contact with the intermediate layer.

A sensing system, comprising:

• an array of Geiger-mode avalanche photodiodes integrated in a semiconductor die, each respective Geiger-mode avalanche photodiode of the array of Geiger-mode avalanche photodiodes including:
• a substrate;
• a front epitaxial layer on the substrate, the front epitaxial layer having a first conductivity type;
• an anode region extending into the front epitaxial layer, the anode region having a second conductivity type that is different from the first conductivity type;
• a plurality of stacked dielectric layers on the front epitaxial layer;
• an intermediate layer on a respective dielectric layer of the plurality of stacked dielectric layers, in contact with the anode region, and the intermediate layer separates the anode region from the plurality of stacked dielectric layers;
• and
• a light source optically coupled to the array of photodiodes, the light source configured to illuminate the array of photodiodes;
• microcontroller circuitry electrically coupled to the array of photodiodes, the microcontroller circuitry configured to receive an output signal of the array;
• and
• a power supply coupled to the array of photodiodes to bias the array of photodiodes.