The Design And Development Of The Monitoring And Control System For A CMP Machine

Integrated circuit is the core technology of electronic information industry. The chemical mechanical polishing (CMP) machine is one of the key equipment in manufacturing integrated circuit. Now, CMP is regarded as the most effective technology to meet the requirement of the surface roughness and flatness of the wafer and obtain damage free surface. To improve the accuracy and surface quality of the wafer in CMP, monitoring and control of the CMP process is very important and has become a developing tendency of CMP machine.In this thesis, at first, a general monitoring and control system is designed, according to the functional requirements of CMP machine. Secondly, all the modules of the system are designed and tested. The pressure control module is designed to control the polishing pressure in real-time, through output 0-10 voltage to the electric valve, which constitutes the closed-loop control with the S-type pressure sensor, data acquisition card for real-time monitoring. The technologies of the interface among motion controller and servo unit are studied, and the controlling mode of "PC + motion controller" is applied in the swing control module. RS-232/RS-485 conversion device and MSComm controller are used in the communication module between PC and inverter. In the vacuum holding module of wafer, the vacuum monitoring circuit is designed in order to collect and monitor the vacuum pressure in real-time.In software development of the monitoring system, a man-machine conversation interface with the style of commercial control system is designed by use of advantage of Windows programming, the language of object-oriented programming (Visual C++) and the way of modularization programming. A lot of functions are realized, such as the input and output of the process parameters, the real-time control of polishing pressure, the acquisition and display of the status data. In addition, this system can output switching signals to control the magnetic valves and relay and realize action control of the machine.Finally, the hardware system is assembled and tested, the software is modified. According to the results of test, the monitoring and control system is proved to meet the requirements of the design.