摘要 |
A multi-electrode electrostatic chuck (20) for holding a substrate (42) such as a silicon wafer during processing is described. The electrostatic chuck (20) comprises (i) a first electrode (22), (ii) a second electrode (24), and (iii) an insulator (26) having a lower portion (26a), a middle portion (26b) and an upper portion (26c). The lower portion (26a) of the insulator (26) is below the first electrode (22) and has a bottom surface (28) suitable for resting the chuck (20) on a support (44) in a process chamber (41). The middle portion (26b) of the insulator (26) lies between the first and second electrodes (22), (24). The upper portion (26c) of the insulator (26) is on the second electrode (24), and has a top surface (30) suitable for holding a substrate (42). The first and second electrodes (22, 24) can have a unipolar or bipolar configurations. In operation, the chuck (20) is placed on a support (44) in a process chamber (41) so that the bottom surface (28) of the chuck (20) rests on the support (44). A substrate (42) is placed on the top surface (30) of the chuck (20). When the first electrode (22) of the chuck (20) is electrically biased with respect to the support (44), a first electrostatic force holds the chuck (20) onto the support (44). When the second electrode (24) of the chuck (20) is electrically biased with respect to the substrate (42) placed on the chuck (20), a second electrostatic force holds the substrate (42) to the chuck (20).
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