Patent ID: 10777427

Abstract:
The temperature of a susceptor made of quartz is increased by heat transfer and heat radiation from a heated semiconductor wafer. When the treated semiconductor wafer is transported outwardly, the susceptor has a non-uniform temperature distribution in which a central portion thereof is higher in temperature than an edge portion thereof. In an early stage of preheating in which a new semiconductor wafer is held by the susceptor and starts being irradiated with light emanating from halogen lamps, an intensity ratio that is the ratio of the intensity of light emanating from a central portion of a light irradiator including an array of the halogen lamps to the intensity of light emanating from an edge portion thereof is less than 100%. Thereafter, the ratio of the intensity of light emanating from the central portion of the light irradiator to the intensity of light emanating from the edge portion thereof is increased.