Method and apparatus for transferring heat from a substrate to a chuck

A method of facilitating the transfer of heat from a substrate having a lower surface and an upper surface to a chuck body having a center, an outer edge and an upper surface, in a low-pressure environment, comprising:

• providing the upper surface of the chuck body with a rough upper surface;
• forming a gap between the rough upper surface and the substrate lower surface by arranging the substrate adjacent the rough surface;
• and
• flowing at least one gas into said gap such that the gas flows towards the outer edge,
• wherein the roughness of the upper surface of the chuck body is selected so that a ratio α/λ is within 5 percent of a maximum value, where α is the accommodation coefficient of the upper surface of the chuck body and α is the mean free path of the gas.

A chuck apparatus for supporting a substrate having an upper and lower surface for facilitating heat transfer away from the substrate during processing of the upper surface of the substrate, comprising:

• a chuck body having an outer edge and a rough upper surface adjacent to which is arranged the substrate lower surface so as to form a gap therebetween;
• and
• a gas conduit passing through said chuck body and having a first end open to said rough upper surface and a second end opposite said first end such that a gas can flow through said conduit into said gap and toward said chuck body outer edge,
• wherein the roughness of the rough upper surface is selected so that a temperature difference between the rough upper surface and the substrate is within 5 percent of a minimum.

A method of facilitating the transfer of heat from a substrate having a lower surface and an upper surface to a chuck body having a center, an outer edge and an upper surface, in a low-pressure environment, comprising:

• providing the upper surface of the chuck body with a rough upper surface;
• forming a gap between the rough upper surface and the substrate lower surface by arranging the substrate adjacent the rough surface;
• and
• flowing at least one gas into said gap such that the gas flows towards the outer edge,
• wherein the roughness of the rough upper surface is selected so that a temperature different between the rough upper surface and the substrate is within 5 percent of a minimum.