Patent ID: 6250914
Filing Date: 2001-06-26
Classification: C23C,C30B,H01L

Abstract:
A wafer heating device comprising:a susceptor having an annular shape for supporting a wafer at an edge thereof;a first heater disposed to face a lower surface of the wafer;a second heater having an annular shape disposed along an outer periphery of the first heater;a temperature control unit for controlling powers of these heaters;a first radiation thermometer for measuring a temperature of a central area of the wafer;a second radiation thermometer for measuring a temperature of a peripheral area of the wafer; anda third radiation thermometer for measuring a temperature of the susceptor,wherein: when there is no wafer on or above the susceptor, the temperature control unit fixes the power of the first heater at a predetermined value, and controls the second heater by using an output of the third radiation thermometer as a feedback signal;when the wafer is held above the susceptor, the temperature control unit controls the first heater by using an output of the first radiation thermometer as a feedback signal, and controls the second heater by using the output of the third radiation thermometer as the feedback signal; andwhen the wafer is set on the susceptor, the temperature control unit controls the first heater by using the output of the first radiation thermometer as the feedback signal, and controls the second heater by using an output of the second radiation thermometer as a feedback signal.