The Influence of Electrode Structure and Wafer Material on Chuck Force of Coulomb Electrostatic Chuck

The electrostatic chuck is a key device in the semiconductor field, and it mainly plays the role of supporting and fixing the wafer. This study uses Maxwell software to simulate the voltage distribution around the electrode when the electrostatic chuck is working. It is concluded that the edge effect of the electrode is less than 4%, and the influence of the edge effect of the electrode on the adsorption force can be ignored. In addition, based on the equivalent capacitance method, a simulation model for calculating the adsorption force of the Coulomb-type electrostatic chuck is established. A vacuum chamber was built for research, and the chucking force of two electrostatic chucks with different electrode structures and the chucking force of electrostatic chucks to wafers of different materials were tested according to the back blowing gas method. The experiment and simulation result shows that the chucking force of the Coulomb-type electrostatic chuck is proportional to the electrode area, and the electrode structure hardly affects the chucking force of the electrostatic chuck. Under the same chucking voltage, for wafers whose backside oxide layer thickness is within 500 nm, the influence of the wafer oxide layer on the chucking force of the Coulomb-type electrostatic chuck is less than 2%, which can be ignored. The research in this paper has important guiding significance for the design and optimization of the electrostatic chuck.