| 摘要 |
Methods and structures are provided for extremely flat wafer chucks, allowing close thermal contact uniformly across a semiconductor processing substrate. An upper and a lower section are tightly fit to one another with flat inner surfaces in face-to-face contact. The sections also define at least one groove therebetween. The two sections have asymmetrical thickness, but the groove defined therebetween is correspondingly asymmetrical such that the groove is centered in the assembled chuck. A heater element, such as a resistive heater, is placed within the groove with some clearance prior to assembling the upper and lower sections. After assembly and tightening, the chuck is thermally cycled above the normal operating temperature prior to secondary machining, thus assuring flatness that is maintained during high temperature operation.
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