Lateral temperature equalizing system for large area surfaces during processing

A method of equalizing the temperature variations across a semiconductor wafer of at least about 300 mm comprising the steps of:

• positioning a semiconductor wafer in heat transfer relation on a support surface above a liquid heat sink disposed within the support including a vaporizable liquid and being coextensive with the wafer area;
• extracting heat by vaporization from regions of the support surface adjacent heated regions of the wafer at proximate ones of a multiplicity of evaporative first sites extending downwards into the liquid heat sink and distributed throughout the liquid heat sink;
• condensing vapor formed by local heating of the wafer at regions above the liquid sink at the closest ones of a plurality of condensing second sites contacting the liquid heat sink and distributed in interdigitated fashion among but separate from the evaporative first sites, and
• passively continuing the process of locally evaporating and condensing to respond to lateral temperature variations of the wafer as the process continues, so as to equalize lateral temperature variations in the wafer.

A method of laterally equalizing the temperature of a

• semiconductor wafer, to maintain the temperature of the wafer surface substantially uniform, as it is supported on its underside on the top surface of a pedestal and heated on its upper side as the pedestal is cooled below the wafer, the method comprising the steps of:
• circulating a gaseous medium between the top surface of the pedestal and portions of the underside of the wafer to extract heat from the heated wafer;
• maintaining a liquid sink of vaporizable liquid within and below the upper surface of the pedestal, the liquid vaporizing at a selected temperature level;
• translating liquid from the liquid sink to below the upper surface of the pedestal by vertical wicking action up through a plurality of wicking paths a really distributed relative to the area of the wafer and extending downwards from the underside of the surface of the pedestal down into the liquid sink to form a plurality of local evaporative sites above the liquid sink and individually responsive to local wafer temperatures that are above the selected temperature level, and
• condensing vapor generated locally in the evaporative sites due to local temperature increases in the wafer by lateral transport of vapor to adjacent ones of a plurality of spaced apart condensing sites distributed throughout the evaporative sites and spaced laterally apart from the evaporative sites, the condensing sites extending from within to above the liquid sink and providing lateral heat transfer from the evaporative sites to equalize the wafer temperature.