Patent ID: 7648579

Claim:
A substrate support system comprising: a substrate holder for holding a substrate, the substrate holder comprising: a central portion having an upper surface, a lower surface, and first and second sets of open passages extending from the upper surface to the lower surface wherein at least some of the first and second sets of open passages have an orientation that is non-parallel with the upper surface of the central portion of the substrate holder; and at least one spacer extending upward from the central portion and having an upper support surface raised above the upper surface of the central portion, the at least one spacer's upper support surface being configured to support a peripheral portion of the substrate so that a gap region exists between the upper surface of the central portion and a bottom surface of the substrate; and a hollow support member having an inlet adapted to engage an outlet of a gas-conveyor to facilitate gas flow from the gas-conveyor into the hollow support member, the hollow support member having one or more upper open ends adapted to support the lower surface of the central portion of the substrate holder, the one or more upper open ends configured to convey gas upward into lower ends of the first set of passages in the central portion of the substrate holder, with upper ends of the first set of passages being configured to convey gas to the gap region, wherein the second set of passages is configured to convey gas from the gap region to the lower surface of the substrate holder without conveying gas into the hollow support member; and wherein the second set of passages comprises first and second subsets of passages, the passages of the first subset being radially inward of the first set of passages, the passages of the second subset of passages being radially outward of the first set of passages, each of the passages of the first subset having an upper end that is radially outward of a lower end of the passage, each of the passages of the second subset having an upper end that is radially inward of a lower end of the passage.