Avalanche photodetector and method for improving high frequency characteristic thereof

Abstract

The invention discloses an avalanche photodetector used for detecting target detection light. The avalanche photodetector comprises an absorbing layer (3), a first electric charge layer (41), a multiplication layer (5), a second electric charge layer (42) and a transition layer (6), wherein the first electric charge layer (41) is N-type doping, and the second electric charge layer (42) is P-type doping. The absorbing layer (3) is used for absorbing the target detection light and converting photons into photoproduction free carrier pairs; the first electric charge layer (41) is used for regulating and controlling the internal electrical field distribution of a device; the multiplication layer (5) is used for enabling the free carriers entering the multiplication layer to initiate avalanche effect, avalanche carrier pairs are accordingly produced, holes in the avalanche carrier pairs longitudinally drift to one end of the avalanche photodetector via the transition layer (6). The avalanche photodetector and method for improving the high frequency characteristic thereof can better regulate the transition time of the carriers and capacitors of the avalanche photodetector and facilitate the improvement of the high frequency characteristic.

Description

technical field [0001] The invention belongs to the field of semiconductor devices, in particular to an avalanche photodetector (APD) and a method for improving its high-frequency characteristics. Background technique [0002] In the past fifty years, avalanche photodetectors (APDs) have been widely used in commercial, military and scientific research, such as quantum information, biomolecular detection, lidar imaging, astronomical detection, etc. In recent years, the driving force of APD research mainly comes from optical communication. The high-speed and high-sensitivity APD with a working wavelength of 1.55 μm is a key device for high-bit-rate long-distance optical fiber communication. Due to its intrinsic gain, APDs can be 5-10 dB more sensitive than PIN type detectors. In the past decade, the performance of APDs has been significantly improved due to the advancement of materials and device structures. At present, APD has been successfully applied in the optical recei...

AI Technical Summary

Problems solved by technology

It can be seen that electrons need a longer time to be collected than holes, which is not conducive to the shortening of carrier transit time and the reduction of device capacitance, thus limiting the high-frequency performance of the device

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