Avalanche photodiode and method of manufacturing the same

Abstract

The invention proposes an avalanche photodiode and a manufacturing method thereof. A light-sensitive region of the avalanche photodiode is completely isolated with a first conductive type of doping region and a second conductive type of doping region, the light-sensitive area is free from the influence of a working voltage and avalanche gain, and the light-sensitive area is encircled by the first conductive type of doping region and the second conductive type of doing region. By the avalanche photodiode, the edge electric leakage can be effectively reduced, and the avalanche photodiode is low in dark current and high in signal-to-noise ratio.

Description

technical field [0001] The invention belongs to the field of basic electrical components, and relates to semiconductor devices, in particular to an avalanche photodiode and a manufacturing method thereof. Background technique [0002] figure 1 It is an existing avalanche photodiode, including: a silicon substrate 7, an oxide layer 6 grown above the silicon substrate 7, the oxide layer 6 and the silicon substrate 7 are bonded to the silicon material device layer, and the silicon material device layer is formed There are P-type doped region 5, N-type doped region 3 and avalanche gain region 1, wherein avalanche gain region 1 is sandwiched between P-type doped region 5 and N-type doped region 3, and photosensitive region 4 is located in the avalanche gain region 1, the photosensitive region 4 is in contact with the avalanche gain region 1 but not in contact with the P-type doped region 5 and the N-type doped region 3, the surface of the P-type doped region 5 is connected to th...

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Problems solved by technology

[0003] The above-mentioned avalanche photodiode belongs to the lateral structure, that is, the diode structure formed by the P-type doped region 5 and the N-type doped region 3 is lateral, and the area of ​​the photosensitive region 4 is also smaller than the avalanche region 1, and the avalanche region 1 is determined according to the operating voltage. Certainly, under a certain working voltage and avalanche gain conditions, the width of the avalanche area 1 is basically fixed, making the size of the photosensitive area 4 not flexible enough, and the photosensitive area is limited

In addition, neither the P-type doped region 5 nor the N-type doped region 3 can form a closed loop on the photosensitive region 4, and there is an edge effect, which leads to leakage of the avalanche photodiode

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