The Research On Hole-triggered Silicon-based Avalanche Photodetectors

Avalanche photodetector is a type of photodetector that can produce avalanche multiplication effect under the influence of strong electric field,and generating internal carrier multiplication.At present,it can be used to detect weak optical communication,optical fiber communication,laser ranging,interplanetary orientation and many other applications in popular areas.This dissertation mainly conducts related research on structural simulation design,production and testing of hole-triggered silicon-based avalanche photodetectors.The specific work is as follows:First,a hole-triggered silicon-based avalanche photodetector structure optimized by the electric field is contrived by regulating electric field in multiplication layer and absorption layer.If one of the ion implantation energy and dose of multiplication layer,the thickness and doping concentration of absorption layer raises performance of the particular aspect of our designed detector,it will attenuate one or two other aspects of the device.Therefore,a reasonable selection is essential to guarantee that the detector has an internal electric field with high peak and high slope.Finally,the carriers can enter the multiplication region at a certain initial velocity,and under acceleration of the optimized high-peak,high-slope electric field in multiplication layer,they can quickly obtain enough energy to cause the avalanche multiplication effect in a short distance,which effectively reduces the avalanche build-up time.Secondly,based on the simulation results of Silvaco software,silicon-based avalanche detector chips with different photosensitive surface diameters,multiplication region diameters,and absorption region thicknesses were prepared,and the dark current,photocurrent,gain,dark current,spectral response,capacitance are experimental tested and analyzed.All of experimental data had been contrasted with simulation results,they are basically the same.Finally,based on the fabricated hole-triggered silicon-based avalanche photodetector,we conducted a temperature coefficient study of breakdown voltage at different temperatures.The devices have different dominant breakdown effects at different operating temperatures.According to the distinct breakdown characteristics of detectors at different operating temperatures,the breakdown effect model of the hole-triggered silicon-based avalanche photodetector was established.Based on the avalanche breakdown model and the actual test data of breakdown voltage,the temperature coefficient of avalanche breakdown voltage in temperature range from250 K to 320 K is 23.3m V/K,while the tunnel breakdown is dominant in the range from 50 K to 150 K,the temperature coefficient of tunnel breakdown voltage is-58.2m V/K.