| 摘要 |
An apparatus and method to position a wafer onto a wafer holder and to maintain a uniform wafer temperature is disclosed. The wafer holder or susceptor comprises a recess or pocket whose surface is concave and includes a grid containing a plurality of grid grooves separating protrusions. The concavity and grid grooves define an enclosed flow volume between a supported wafer and the susceptor surface, as well as an escape area, or total cross-sectional area of the grid grooves opening out from under the periphery of the wafer. These are chosen to reduce the wafer slide and curl during wafer drop-off and wafer stick during wafer pick-up, while improving thermal uniformity and reducing particle problems. In another embodiment, centering locators in the form of thin, radially placed protrusions are provided around the edge of the susceptor pocket to reduce further the possibility of contact between the wafer and the outer edge of the susceptor. These features help to achieve temperature uniformity, and therefore quality of the process result, across the wafer during processing.
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