Design And Implementation Of Computer Controlled MOCVD System

Modern MOCVD technology has been a key technology in developing andmanufacturing advanced compound semiconductor materials. In this paper, based ondeveloping MOCVD system grown GaN material, a computer controlled system iswell implemented for the control and management of the whole material-growingprocess. In the system a two-level distributed control structure is applied for its automaticcontrol, in which one industrial control computer is adopted for supervisory controland data processing, some intelligent instruments for the field control and five dataacquisition and control cards for the communication between the computer and thecontrolled devices. With the modular programming method the application software ofthe control system is divided into some function modules. The monitor interfaces ofthe control process are created by the graphic display technique, which is friendly andbeautiful and easy to operate. To insure the high reliability needed, some seriousanti-interference measures are taken in both the hardware and the software of thesystem. According to its testing results, the control system is easy to operate, high incontrol accuracy and stable and reliable in running, which is satisfactory for theMOCVD system in material growth.