WAFER SUPPORT HAVING PRESSURE ZONE WHERE TEMPERATURE FEEDBACK AND CONTACT AREA ARE SMALL

摘要

PROBLEM TO BE SOLVED: To provide a method for controlling many pressure zones formed on the surface of a wafer support at specified pressures. SOLUTION: In order to control two zones 68 and 70 at different gas pressures, a sealing region 72 is formed between the two zones 68 and 70. High gas pressure is applied to the zone corresponding to a wafer W region to which mush heat should be transferred. The distance between a wafer support 64 and the wafer W is so determined that a specified amount of heat may be transferred to the wafer W. In the other conditions, the contact between the wafer supporter 64 and the wafer W is so controlled using projections 66 that a heat transfer gas flow may be maximum. A closed loop control system changes the heat transfer gas pressure according to a temperature sensor 96. Regarding an electrostatic chuck, the thickness of a dielectric body 86 can be varied so as to apply high electrostatic force to a peripheral region of the wafer W.