Identification Research on CMP Multi-Zones Pressure System

Abstract

In the process of very large scale integrated circuit (VLSI) manufacturing, Chemical Mechanical Polishing (CMP) technique is one of the most effective wafer global planarization techniques. The polishing quality depends not only on the slurry and polishing head structure, but also on accurately wafer polishing pressure control. However, the polishing pressure accurately control depends on a generalized pressure control system of the polishing head and multi-zones pneumatic pressure system. As the system has time-varying, nonlinear and coupling characters, it is difficult to apply theoretical modeling method for obtaining the accurate mathematical model. Therefore, this paper presents a method based on subsubmodel identification to establish the precise mathematical model of the pressure control system. The experimental results show that the method is feasible, practical and accurate.