Simulation On Electron Transport Process Of EBCMOs

With the development of low light level night vision technology,electron bombarded CMOS sensor(EBCMOS)has a broad application prospect in remote sensing,night vision imaging,particle physics,astronomical observation and other fields due to its advantages of high sensitivity,low noise,low power consumption and small size,and has become a research hotspot in the field of relevant research at home and abroad.In this paper,electron transport model and Monte Carlo method are used to establish a complete electron trajectory model in the device,and the related simulation experiments are carried out.The charge collection efficiency of EBCMOS with uniform doping and gradient doping of P-type substrate was simulated.Various structure models of EBCMOS were designed,and the effect of different structure on charge collection efficiency of EBCMOS imaging device was simulated and analyzed.Based on carrier transport theory and Monte Carlo simulation method,the trajectories of electrons in EBCMOS are simulated by using mathematical modeling software MATLAB.Theoretical derivation and model establishment were carried out for the electron movement trajectory model in the proximity region,dead layer,diffusion region and depletion region,and the electron multiplication process was modeled,and the charge collection efficiency model in pixel region was established.The influence of dead layer voltage and thickness on incident electron loss rate,the influence of proximity layer voltage on the number of multiplying electrons,and the influence factors of charge collection efficiency under uniform substrate doping are studied in detail from four aspects of proximity layer distance,proximity layer voltage,doping concentration and substrate thickness.The theoretical model of gradient doping trajectory was established,and then the electron trajectory was simulated by global gradient doping and piecewise gradient doping,and the influence of different doping models on charge collection efficiency was analyzed.Finally,a doping structure model with high charge collection efficiency is obtained.The simulation results in this paper can provide theoretical guidance for the device preparation of high-performance EBCMOS.