The Mechanical System Design Of A Chemical Mechanical Polishing Machine

With the development of the IC (intergrated circuit) processing technology, wafer size is increasing, the device feature size is scaling down, the demands for surface quality and planarization of wafer become higher and higher. At the present time, chemical mechanical planarization (CMP) is the most effective technology for global and local planarization of the wafer in IC manufacturing.A CMP machine is a application base of CMP technology, and shows the development level of CMP technology. It is not only a mechanical system, but becomes complicated automatization system integrating many relative technology and system, such as real time control of process, monitoring of end-point, on-line measure of wafer, applying of slurry and transortion of wafer, pad dressing, CMP post-cleaning and so on. It is important to develop the CMP equipment in our country.This thesis mainly deals with design of the mechanical system of a CMP machine.Based on the analysis of the CMP principles, for different kinematic forms, the mathematic models of the material removal rate on wafer in CMP are established, the effects of the kinematic forms and process parameters on material removal rate and material removal non-uniformity are analyzed, and the relations between the material removal rate and the process parameters in different the kinematic forms are revealed. Then two types of polishing machine, with arc oscillating and linear reciprocating polishing head, are selected. It is shown that the machinism of the ronter is more complicated than the latter, though there are a little difference in material removal non-uniformity and material removal rate of both machines. The polishing machine with a linear reciprocating polishing head is designed in detail, and the static anaylsis of some key parts are carried out.