Influence of Wafer Material on Chuck Force of J-R Type Electrostatic Chuck

Electrostatic chuck is one of the most important elements in the semiconductor field, mainly used in integrated circuit equipment and optical equipment, which plays the role of carrying wafers and substrates. This research introduces the vacuum chamber and uses the back gas method to test the chuck force of the Johnsen-Rahbek type electrostatic chuck with different thicknesses of the oxide layer of the wafer and in different chuck voltages. In this article, we infer that the chuck force comes from the Coulomb force between the electrostatic chuck and the silicon in the wafer by studying the electrical properties of the oxide layer and the structure of the mesa. We built the mathematical model to study the effect of the thickness of the oxide layer of the wafer in chuck force with the equivalent capacitance method. The experiment and simulation results show that because of the low contact resistance, under the same chuck voltage, the chuck force of the electrostatic chuck to the wafer with the oxide layer is greater than that of the electrostatic chuck to the bare silicon wafer. And with increasing the thickness of the oxide layer of the wafer, the chuck force between the electrostatic chuck and wafer increases first and then decreases. This research has important guidance for the improvement of the Johnsen-Rahbek effect theory and the optimization of the structure of the electrostatic chuck, and provides a theoretical basis for the development of semiconductor equipment.