Avalanche photodiode and manufacturing method thereof

Abstract

The invention discloses an avalanche photodiode and a manufacturing method thereof. The method comprises the following steps: manufacturing a substrate, a first contact layer and a second contact layer; evaporating a passivation layer on the second contact layer; etching the passivation layer and the second contact layer to form a second window and a first window, and enabling the second window and the first window to be step-shaped; performing zinc diffusion through the second window and the first window, and controlling the diffusion depth, so that a diffusion region comprising an edge region and a central region is formed in the first contact layer, and the diffusion depth of the edge region is 300-900 nanometers smaller than that of the central region. According to the invention, the problem that the edge area is difficult to control during zinc diffusion and the problem of edge pre-breakdown caused by the problem can be effectively solved.

Description

technical field

[0001] The invention relates to the technical field of zinc diffusion technology, in particular to an avalanche photodiode and a manufacturing method thereof. Background technique

[0002] The zinc diffusion process is a technique used to define p-type doped regions in the manufacture of various optoelectronic and electronic devices. Taking the planar APD (Avalanche Photodiodes) based on indium phosphide (InP) as an example, the epitaxial structure (the distribution of materials in each layer in the vertical direction) can have some different changes, and the manufacturing process is based on epitaxial growth. Determine the thickness and doping of each layer except the top layer, reserve a certain thickness of low-doped or non-doped semiconductor material as the top layer, and then use the zinc diffusion process to do p-type doping on the part of the top layer close to the surface, the top layer of semiconductor The part of the material that is not doped wit...

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