Avalanche photodetector and method for increasing high frequency characteristics of avalanche photodetector

Abstract

The invention discloses an avalanche photodetector and a method for increasing high frequency characteristics of the avalanche photodetector. The avalanche photodetector is used for detecting target detecting light and comprises an absorbing layer (8), a first charge layer (61), a multiplication layer (5), a second charge layer (62) and a transition layer which are arrayed in turn along the longitudinal direction, wherein the absorbing layer (8) is used for absorbing the target detecting light and converting photons of the target detecting light into photo-produced free carrier pairs; the first charge layer (61) is used for regulating and controlling the electric field distribution in a device; the multiplication layer (5) is used for causing the free carriers entering into the multiplication layer to trigger an avalanche effect and generate avalanche carrier pairs; and one type of carrier in the avalanche carrier pairs longitudinally drifts to one end of the avalanche photodetector through the transition layer (9). The avalanche photodetector can better regulate the capacitance of the avalanche photodetector and the transition time of the carriers and is beneficial to the increasing of the high frequency characteristics of the avalanche photodetector.

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 the high-frequency characteristics of the avalanche photodetector. Background technique [0002] Over the past five decades, 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. A high-speed, high-sensitivity APD with an operating wavelength of 1.55 μm is a key device for high-bit-rate long-distance optical fiber communications. Due to its intrinsic gain, APDs can be 5-10 dB more sensitive than PIN-type detectors. Over the past decade, the performance of APDs has significantly improved due to advances in materials and device structures. At present, APD has been successfully used ...

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Problems solved by technology

It can be seen that it takes a longer time for holes to be collected than electrons, which is not conducive to the shortening of

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