Method for preventing an electrostatic chuck from being corroded during a cleaning process

摘要

The present invention relates to a method for preventing an electrostatic chuck positioned at the bottom of a plasma vacuum chamber from being corroded during a cleaning process. The electrostatic chuck comprises a conductive substrate functioned as a lower electrode in a plasma process, and an insulating layer on the conductive substrate to electrically isolate the semiconductor wafer and the conductive substrate. The cleaning process involves a plasma process in which a fluorine-contained gas is injected into the plasma vacuum chamber to remove the chemical layer on the inner wall of the plasma vacuum chamber. A ceramic shutter made of SiC material is reposed on the electrostatic chuck and a high DC voltage is applied to the conductive substrate and the ceramic shutter which causes the ceramic shutter and the electrostatic chuck tightly stick together due to an electrostatic reaction. By doing so, the fluorine-contained gas cannot corrode the insulating layer under the ceramic shutter through the gap between the ceramic shutter and the electrostatic chuck.