Avalanche photodiode based on multi-period Bragg reflector and preparation method thereof

Abstract

The invention discloses an avalanche photodiode based on a multi-period Bragg reflector and a preparation method thereof. The avalanche photodiode comprises an anode, a Ge electrode contact layer, an absorption layer, a charge layer, a multiplication layer, a cathode, an SOI substrate, a protection layer, a first multi-period Bragg reflector, a second multi-period Bragg reflector, a third multi-period Bragg reflector and an optical waveguide, wherein the third multi-period Bragg reflector is stacked in the SOI substrate; and the cathode comprises a first cathode part and a second cathode part which are arranged on the upper surface of the SOI substrate, the first multi-period Bragg reflector is located between the first cathode part and a laminated structure formed by the multiplication layer and the charge layer, and the second multi-period Bragg reflector is located between the second cathode part and the laminated structure. According to the avalanche photodiode, the strong reflection effect of the multi-period Bragg reflector is utilized, the coupling efficiency of light can be improved, the light absorption of a device is enhanced, and the responsivity of the device is effectively improved.

Description

technical field [0001] The invention belongs to the technical field of photodetectors, and in particular relates to an avalanche photodiode based on a multi-period Bragg reflector and a preparation method thereof. Background technique [0002] With the rapid development of today's informatization and Internet business, optical fiber communication system, as one of the main technical pillars of informatization, has become a very important strategic industry. With the rapid development of optical fiber communication and quantum communication technology, there is an urgent need for high-speed, long-distance, and low-cost optical fiber communication systems. [0003] One of the important components of optical fiber communication is the photodetector, which uses the principle of the photoelectric effect to respond to the received optical signal and convert it into an electrical signal output. In order to realize high-performance and low-cost optical fiber communication, there is...

AI Technical Summary

Problems solved by technology

Some new device structures and improvements have been proposed, such as a waveguide APD with a low height profile. Although this structure improves the collection of photogenerated carriers by the fringe electric field, the fringe electric field is difficult to control and will generate high noise. ; For example, a stepped waveguide APD structure, which improves the coupling efficiency of the waveguide, but has a greater impact on light absorption; therefore, how to further improve the coupling efficiency and light absorption of the waveguide APD, and reduce the dark current of the device , is still the key problem that needs to be solved urgently

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