Simulation Of GaSb Film Epitaxy Growth

A Monte-Carlo method has been developed for simulating the growth of epitaxy flims.The program was compiled using Turbo BASIC language.The influence of growth rate and temperature on surface morphology was studied.The model we used was an advanced diffusion limited aggregation(DLA) model.The process of deposition and diffusion were considered in this model.Through simulation, the morphology of the films grown under different rates and substrate temperature was obtained, and the growth mode under different condition was analyzed. The simulation showed that when the temperature was 500℃and the growth rate was 0.64ML/s,the film grew in layer-by-layer mode.When the growth rate was 1.28ML/s, the growth mode of the film was Stranksi-Krastanow mode, and Volmer-Weber mode became the growth mode of the flim when the rate was 2.56ML/s.Except when the temperature is 300℃, the films grew in layer-by-layer mode in all other temperatures.The relation between surface roughness and covering pecentage was obtained by analysing the simulation result. When the growth rate was 0.64 ML/s or 1.28ML/s, the relation was perieodic oscillation.While the rate was 2.56ML/s or 5.12ML/s, the value of the roughness increased continously as the covering pecentage raised. It was also found that the number of active atoms has relation with the length of border when the growth rate was low, and the number was largest as the length was shortest. When the rate is great, the length of border rose sharply, if it reached the critical value, the increase became slow.Besides,the growth of GaSb expitaxy film was monitored by reflection high energy electron diffraction (RHEED).The RHEED images and intesity oscillation are collected by computer system.It showed that the GaSb film prepared in 400℃was amorphous and it became monocrystalline when the temperature rose to 500℃.Atomic force microscope (AFM) was applied to analyse the surface morphology of the films which were grown in diffrent growth rates or substrate temperature.The analysis were compared to simulation results.The experiment results indicated it was easy to form clusters when the rate of growth is high or...