Wafer holder with peripheral lift ring

摘要

A wafer holder for supporting a wafer within a CVD processing chamber includes a vertically moveable lift ring configured to support the bottom peripheral surface of the wafer, and an inner plug having a top flat surface configured to support the wafer during wafer processing. The lift ring has a central aperture configured to closely surround the inner plug. When a wafer is to be loaded onto the wafer holder, the lift ring is elevated above the inner plug. The wafer is loaded onto the lift ring in the elevated position. Then, the lift ring is maintained in the elevated position for a time period sufficient to allow the wafer temperature to rise to a level that is sufficient to significantly reduce or even substantially prevent thermal shock to the wafer when the wafer is brought into contact with the inner plug. The lift ring is then lowered into surrounding engagement with the inner plug. This is the wafer processing position of the wafer holder.