Silicon photo-detector having gain under low bias voltage and preparation method of silicon photo-detector

Abstract

The invention discloses a silicon photo-detector having a gain under low bias voltage. The silicon photo-detector comprises a silicon (Si) substrate, an n+ type Si layer, a first electrode, a second semiconductor junction and a second electrode, wherein the n+ type Si layer is subjected to the super-saturation substitutional doping of chalcogen; the n+ type Si layer and the first electrode are formed on a first surface of the Si substrate sequentially; the n+ type Si layer which is subjected to the super-saturation substitutional doping of the chalcogen and the Si substrate form a first semiconductor junction; and the second semiconductor junction and the second electrode are formed on a second surface of the Si substrate sequentially. Meanwhile, the invention discloses a method for preparing the silicon photo-detector having the gain under the low bias voltage. By the invention, because laser doping is changed into ion injection and laser radiation, the super-saturation substitutional doping of impurities is formed in a heavy-doping region as much as possible, and a Si surface can be further kept smooth. The invention is applied to micro-electronic processing of device chips, andthe prepared silicon photo-detector can be characterized by having a photoelectric gain under the low bias voltage, so that the flexibility of the silicon photo-detector is further improved, and the application range of the silicon photo-detector is expanded.

Description

technical field [0001] The invention relates to the technical field of Si optoelectronic materials, in particular to a silicon photodetector with gain under low bias voltage and a preparation method thereof. Background technique [0002] From the perspective of device structure, silicon photodetectors mainly have two types of device structures: p-intrinsic-n (pin) and avalanche. [1] . The pin structure device is simple, the photoelectric response is 1A / W, and it can be connected to the integrated circuit due to the low bias voltage; the structure of the avalanche device is pnπn type, although its photoelectric response is about 100A / W, because it must use 100-200V High voltage, so can only be used with discrete devices. [0003] From the perspective of detection mechanism, the types of photodetectors can be divided into two types: photoconductive and photovoltaic. [2] . The photoconductive detector is that the valence band electrons in the material are excited to the con...

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Problems solved by technology

The pin structure device is simple, the photoelectric response is 1A / W, and can be connected to the integrated circuit due to the low bias voltage; the structure of the avalanche device is pnπn type, although its photoelectric response is about 100A / W, but because it must use 100-200V high voltage, so only for discrete

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