Temperature Control System Design Of MOCVD

This article mainly studies the temperature control system of MOCVD. As a key technology of MOCVD, the temperature control system has always been a hot issue. This article firstly introduces the composition of MOCVD, and makes a brief description for each part, mainly the structure of the reaction chamber. Then introduces the specific reaction process in detail, which corresponds to the special range of temperature control. Due to the high cost of MOCVD equipment, we established a set of software and hardware simulation platform. The hardware platform includes an object model based on xPC Target and an Eurotherm temperature controller. The software platform mainly includes the xPC Target monitoring software and the temperature control monitoring software.The designed temperature control algorithms in this article are all tested on the simulation platform before applying to the real system. The control methods used in this article mainly include the conventional PID, the piecewise PID, fuzzy PID and neural network PID. Firstly introduces the working principle of the conventional PID and applies it into the system, then analyzes the effect of the controller. Because the conventional PID is not suitable for all temperature range, this paper uses piecewise PID instead, and good result has been achieved. In order to better adapt to the differences between equipment, this paper then introduces the intelligent control algorithm, including the variable universe fuzzy PID and the neural network PID based on modeling. The simulation of this two algorithms shows an ideal result have been achieved.