Avalanche photodiode optimized based on photonic crystal broadband total reflector

Abstract

The present invention discloses an avalanche photodiode optimized based on a photonic crystal broadband total reflector and a manufacturing method thereof. The avalanche photodiode is a one-dimensional photonic crystal broadband total reflector alternately formed by multiple layers of SiO2 dielectric films and TiO2 dielectric films at the back surface of the substrate of a normal incidence avalanche photodiode or the front surface of a back incidence avalanche photodiode. The one-dimensional photonic crystal broadband total reflector reflects light which is not absorbed by an absorption layerin the incident light back to the absorption layer in the avalanche photodiode for absorption again. Compared to a current avalanche photodiode, the one-dimensional photonic crystal broadband total reflector is added to reflect the light which is not absorbed by the absorption layer back to the absorption layer for secondary absorption for all the incident light with different angles with opticalcommunication wave bands of 1310-1675nm without influence of the device frequency response so as to increase the quantum efficiency and responsivity of the device and improve about 50% performances ofthe device.

Description

technical field [0001] The invention relates to the technical field of photodetectors, in particular to an optimized avalanche photodiode based on a photonic crystal wide-spectrum total reflector and a manufacturing method thereof. Background technique [0002] With the development of optoelectronic technology, high-frequency, low-noise and high-sensitivity avalanche photodiodes (Avalanche Photodiodes, APD) are increasingly being used in high-bit-rate, long-distance optical fiber communication systems. Among them, the APD detector with InGaAs / InP absorption, gradient, charge, multiplication (Separate Absorption, Grading, Charge and Multiplication, SAGCM) structure, its composition material In 0.53 Ga 0.47 The forbidden band width of As is 0.75ev, and the absorption coefficient reaches 10 in the wavelength range of 1-1.7 microns. 4 cm -1 , where the absorption coefficient at 1550nm is 0.67*10 4 cm -1 . [0003] When manufacturing an avalanche diode with high-frequency r...

AI Technical Summary

Problems solved by technology

One is to use a metal electrode as the reflective layer, but its high near-infrared absorption rate and the uneven surface caused by the alloy cause scattering, resulting in low reflection efficiency; the other is to add a distributed Bragg reflector with high reflectivity (distributedBragg reflection, DBR) , but the fixed optical thickness of its structure and the limitation of materials lead to a generally small high reflectivity spectrum, and it is difficult to design a total reflector that can just cover the full optical communication band (1310-1675nm) with a wide spectrum and different incident angles

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