| 摘要 |
A shield (5) for an electrostatic chuck (4) includes a first shield member (60) circumscribing the chuck and a second shield member (62) supported over the first shield member. The second shield member has an upper surface surrounding the wafer and exposed to deposition from gases within the process chamber. Splitting the shield into two members increases the ratio of exposed surface to thermal mass of the second shield member, which increases the temperature of the second shield member during processing, thereby decreasing the rate of deposition thereon. In addition, the clean rate or deposition removal rate of the shield is typically a function of its temperature (i.e., the hotter the shield becomes during processing, the faster it can be cleaned). Therefore, the clean rate of the second shield member will be increased, thereby enhancing the throughput of the process.
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