Theoretical Modeling And Parameter Optimization Of Lateral Multi-Buffer Layer SAM Avalanche Photodiode Bsaed On SOI Film

In recent years,photoelectric detection technology has been widely used in fields such as people's livelihood economy,social production and national defense.Single-photon detection technology with high sensitivity,as an important technology in photoelectric detection,is widely used to detect weak light or single-photon signals.Compared with other single-photon detectors,single photon avalanche diode(SPAD)working in Geiger mode have the advantages of fast response rate,large internal gain and high sensitivity,so that SPAD can be widely used the field of single-photon detection,such as quantum information,detection imaging,medical diagnosis and laser measurement.Aiming at the 400nm wavelength blue-violet light detection requirements for weak light signals,a LSAMBM APD based on SOI film proposed by the laboratory research group.Completed the model construction and calculation of LSAMBM SPAD detection efficiency and dark count rate working in Geiger-mode.In addition,by optimizing the device layout structure and structural parameters,the performance of the device is further improved.Firstly,the photon detection efficiency and dark count rate of LSAMBM SAPD based on SOI film operating in Geiger-mode are modeled and calculated.Under the excess bias voltage is 1V,the detection efficiency is more than 30%in the wavelength range of 390?570nm,of which the peak detection efficiency is 40.8%,and the dark count rate is 495Hz.These results show that the device has good detection efficiency,wide spectral response and low dark count rate,and can be well applied to single-photon detection.Secondly,a circular layout with lateral multi-buffer SAM structure avalanche photodiode based on SOI film was designed.Compared with the previous rectangular layout,the circular layout has a shorter absorption region length while ensuring that the active area is the same as other process parameters,which can enhance the electric field intensity of the absorption region,and more effectively separate photo-generated carriers.In addition,the carriers will be accelerated faster in the higher electric field absorption region to achieve high-speed frequency response.Thus,the contradiction between responsivity and frequency response can be resolved more effectively.The ?-? characteristics,light-dark current and frequency response of LSAMBM-C APD were simulated by using Silvaco software.The avalanche voltage was 8.11V,and the dark current was 6.01fA when the reverse bias voltage was 4V.At 0.001 W/cm2 and 400nm incident light and 8.11V reverse bias voltage,the responsivity was as high as1236.9A/W and the frequency response reached 3.2GHz@9.2V.Finally,the main regional structural parameters of LSAMBM-C APD were optimized by the multi-value optimization method.The avalanche voltage of the optimized LSAMBM-C APD was 6.7V,and the frequency response reached 15GHz@9.2V.