Avalanche photodetector (variants) and method for manufacturing the same (variants)

A method of manufacturing an avalanche photodetector, the method comprising:

• forming a multiplication layer on an entire top surface of a semiconductor wafer;
• forming at least one avalanche amplifier in a region on top of the multiplication layer, by (i) etching a circular groove along the boundaries of the region of the multiplication layer, so that a depth of the groove is less than a thickness of the multiplication layer;
• (ii) filling the circular groove with a dielectric material;
• and (iii) forming a contact layer of the at least one avalanche amplifier inside the region bounded by the circular groove, to thereby form a photoconverter layer inside the region bounded by the circular groove and outside the contact layer;
• forming a dielectric layer on a top surface of the photoconverter layer;
• forming a first electrode made of a transparent material on top surfaces of both the contact layer and dielectric layer;
• and
• forming a second electrode on a bottom surface of the semiconductor wafer.

A method of manufacturing an avalanche photodetector, the method comprising:

• forming a multiplication layer on an entire top surface of a semiconductor wafer,
• etching a closed groove on a top surface of the multiplication layer, so that a depth of the groove is greater than or equal to a thickness of the multiplication layer, but is smaller than a total thickness of the semiconductor wafer and the multiplication layer combined;
• forming a photodetector inside a region bounded by the closed groove;
• filling the closed groove with highly-doped polycrystalline silicon of the same conductivity type as the multiplication layer;
• forming at least one avalanche amplifier in the top surface of the multiplication layer in an area bounded by the closed groove, by (i) etching a circular groove inside a region of the multiplication layer bounded by the closed groove, wherein the circular groove defines the avalanche amplifier, and wherein a depth of the circular groove is less than a thickness of the multiplication layer;
• (ii) filling the circular groove with a dielectric material;
• and (iii) placing a contact layer of the at least one avalanche amplifier inside a region bounded by the circular groove so as to form a photoconverter layer outside the region bounded by the circular groove and inside the closed groove;
• forming a dielectric layer on a top surface of the photoconverter layer;
• forming a first electrode made of a transparent material on top of the surfaces of both the contact layer and the dielectric layer;
• and
• forming a second electrode on a bottom surface of the semiconductor wafer.

An avalanche photodetector, the photodetector comprising:

• a semiconductor wafer;
• a multiplication layer covering an entire top surface of the semiconductor wafer;
• a contact layer covering a portion of the multiplication layer, which is bounded by a dielectric-filled circular groove, wherein a depth of the circular groove is less than a thickness of the multiplication layer, and wherein the contact layer forms at least one avalanche amplifier and a photoconverter layer inside the circular groove;
• a dielectric layer covering the top surface of the photoconverter layer;
• a transparent first electrode covering upper surfaces of both the contact layer and the dielectric layer;
• and
• a second electrode formed on a bottom surface of the semiconductor wafer.

An avalanche photodetector, the photodetector comprising:

• a semiconductor wafer;
• a multiplication layer covering an entire surface of the semiconductor wafer;
• a contact layer on top of a portion of the multiplication layer, which is bounded by a dielectric-filled circular groove, whose depth is less than the multiplication layer thickness, wherein the contact layer forms at least one avalanche amplifier and photoconverter inside the closed groove;
• a dielectric layer covering a top surface of the photoconverter;
• a transparent first electrode covering top surfaces of both the contact layer and the dielectric layer;
• a closed groove, whose depth is greater than or equal to a thickness of the multiplication layer, but less than a total thickness of the semiconductor wafer and the multiplication layer combined, and wherein the closed groove is filled with highly-doped polycrystalline silicon of the same conductivity type as the multiplication layer, and wherein avalanche amplifiers and the photoconverter are located inside the region bounded by the closed groove;
• a high-resistance layer sandwiched between the contact layer and the first electrode;
• and
• a second electrode on a bottom surface of the semiconductor wafer.