Patent attributes
A susceptor is preheated through light irradiation by a halogen lamp before the first semiconductor wafer of a lot as a processing target is transferred into a chamber. The temperature of the susceptor is measured by a radiation thermometer. A control unit is configured to control the output of the halogen lamp so that the temperature of the susceptor reaches a stable temperature based on a result of the measurement of the temperature of the susceptor by the radiation thermometer. The stable temperature of the susceptor is the temperature of the susceptor when the temperature of the susceptor is risen to a constant temperature by continuously performing light irradiation heating on a plurality of semiconductor wafers in the chamber without heating the susceptor.
