Patent ID: 6893507

Claim:
A semiconductor reactor for treating a substrate, comprising: a reaction chamber; a plurality of heat sources; a self-centering single-wafer support structure, having a first level and centered position at a first temperature and a second level and centered position at a second temperature, including: a wafer holder for directly supporting the substrate, having a first coefficient of thermal expansion, and the wafer holder comprising at least one recess in a bottom surface thereof, and a support spider for supporting the wafer holder, having a second coefficient of thermal expansion different from the first coefficient, the spider comprising at least three support posts cooperating with the recess of the wafer holder; wherein the recess comprises at least three radial grooves corresponding to the support posts of the spider, distributed at even angular distances from one another about the wafer holder bottom surface, each of the radial grooves sloping from a first level at a first radial position to a second level at a second radial position.