Patent ID: 7347901

Claim:
A thermally zoned substrate holder, comprising: a base upper portion having top and bottom surfaces, the top surface configured to support a substrate and the bottom surface having a recess formed therein; a plurality of temperature control elements inside the recess, each element having a top surface seated in the recess and a bottom surface forming a floor of said recess; at least one thermal insulator having a lower coefficient of thermal conductivity than a material of the base, the at least one insulator being positioned within said recess and disposed between the plurality of temperature control elements and substantially thermally separating the plurality of temperature control elements; and a base lower portion positioned within said recess and seated to said floor of said recess to substantially fill said recess, wherein the at least one insulator comprises a gas chamber configured to receive a gas at a predetermined pressure via a piping system disposed in the base upper portion which couples the gas chamber to an external gas supply.