Research On Temperature Control Strategy Of MOCVD Based On Epitaxial Cavity

Metal Organic Chemical Vapor Deposition(MOCVD)is the most critical technology for the production of semiconductor wafers.Due to the rapid dev－elopment of semiconductor technology,the market demand of MOCVD growth technology is increasing day by day.However,most of the MOCVD equipment required is derived from imports for domestic manufacturers of semiconductor materials.Therefore,the research of MOCVD devices which can produce high quality semiconductor materials(gallium nitride)is of great significance andalso has great market value and prospect.This paper first introduces the research situation of the growth technology of metal organic chemical vapor deposition(MOCVD),and next introduces the background and status quo of domestic and overseas.Then a simple overview is to the hardware composition and working process of the MOCVD temperature control system.After that an analysis of temperature control characteristics is about MOCVD extension cavity according to the structure and working process.The analysis shows that the temperature control system of MOCVD extended cavity has the attribute of "large hysteresis" and "nonlinear" and "time parameter".According to the idea of mathematical modeling,using the principle of system identification is a basis and system identification method is a tool to handle the relevant experimental data to found the mathematical model of the temperature control system in the MOCVD reaction cavity.In this paper,the model of the temperature control system is studied on the basis of the PID control algorithm,and the integral separation PID algorithm and the variable speed integral PID algorithm are studied.The algorithm and its improved algorithm are simulated and analyzed their respective characteristics by the Simulink simulation environment of MATLAB.In order to improve the system’s nonlinear and adaptive,the fuzzy control algorithm is proposed,and the algorithm is simulated,and then its characteristics and advantages and disadvantages are analyzed.The simulation result show that the system has good control effect.If the algorithm be used in the temperature control system of the MOCVD reaction cavity,it has a very application value and prospects.