Electrostatic chuck with improved erosion resistance

摘要

An electrostatic chuck (20) for holding a substrate (45) is described. One version of the chuck (20) suitable for mounting on a base (25), comprises (i) an electrostatic member (33) having an electrode (50) therein, and (ii) an electrical lead (60) extending through the base (25) to electrically engage the electrode (50) of the electrostatic member (33). When the chuck (20) is used to hold a substrate (45) in a process chamber (80) containing erosive process gas, the substrate (45) covers and substantially protects the electrical lead (60) from erosion by the erosive process gas. In a preferred version of the chuck (20), an electrical connector (55) forming an integral extension of the electrode (50), electrically connects the electrode (50) to a voltage supply terminal (70) used to operate the chuck (20). The electrical connector (55) comprises (i) an electrical lead (60) that extends through the base (25), and (ii) an electrical contact (65) on the electrical lead (60), the contact sized sufficiently large to directly contact and electrically engage the voltage supply terminal (70). The electrode (50) of the chuck (20) can comprise first and second electrodes (130), (135) electrically isolated from one another by an electrical isolation void (52), the electrodes sized and configured so that the electrical isolation void (52) can serve as a cooling groove (105) for holding coolant for cooling the substrate (45) held on the chuck (20). Preferably, the two electrode chuck (20) is used in conjunction with a switching system capable of operating the chuck (20) in either a monopolar mode or in a bipolar mode.