Study Of Speed Performance For SOI Lateral PIN Photodetector Gated By Transparent Electrode

With the rapid development of semiconductor technology and information technology,photosensitive devices play a key role in industrial techonology,national defence and military technology,and mordern civil technology.Therefore,an increasing demand for low-cost and high-performance photodetectors with high photocurrent,sensitivity,responsivity,low dark current and excellent speed performance in applications like optical communication and monitoring systems in environmental and biomedical applications,greatly promotes the development of light detection at short wavelengths.Thin-film silicon-on-insulator(SOI)lateral PIN photodetector gated by transparent electrode(SOI LPIN PD-GTE),which combines the advantages of typical CMOS SOI technology,lateral PIN photodiode and BJMOSFET,owns outstanding optoelectronic performances and speed performance.This paper analyses the structure and operation principles of SOI LPIN PD-GTE.Based on the device structure,an analytical model of the SOI LPIN PD-GTE speed performance is presented.Considering different incident wavelengths,doping concentrations in intrinsic,P+ and N+ regions,and intrinsic region lengths,the speed performances of SOI LPIN PD-GTE is analyzed and optimized under various incident wavelengths and different temperetures,which is validated by two dimensional(2D)Atlas numerical simulation.The simulation results in standard devices(1018 cm-3,doping concentration in the P+?N+ region,1015 cm-3 in the intrinsic region and intrinsic length Li=8?m)indicate stable-3dB bandwidth of ca.28 MHz with gate voltage of 0.5V below 400nm at 300K and decrease by the increasing temperature.With improved doping concentration of 1020cm-3 in the P+,N+ region and 1016cm-3 in the intrinsic region,the total-3dB bandwidth with 1V gate voltage below 400nm for Li=1?m reaches 21.8G Hz at 300K and 11.2G Hz at 573K.In the long-wavelength spectral range from 400nm to 680nm,the total-3dB bandwidth decreases dramatically to only about 10MHz.In this work,speed performance of SOI LPIN PD-GTE is optimized at high temperature.Meanwhile,optimized SOI LPIN PD-GTE exhibits device bandwidths over 20GHz and excellent speed performance in the ultraviolet and near visible spectral region and capability of high-speed phtodetection in harsh environments.