Patent ID: 10643869

Abstract:
A semiconductor wafer that has a plane orientation of (100) and is made of monocrystalline silicon is warped along an axis, i.e., a diameter along a <100> direction of the semiconductor wafer when irradiated with a flash of light. The semiconductor wafer is placed on a susceptor while the direction of the semiconductor wafer is adjusted so that the diameter along the <100> direction coincides with an optical axis of an upper radiation thermometer. This adjustment makes a diameter along a direction in which a warp of the semiconductor wafer is smallest during irradiation with a flash of light coincide with the optical axis of the upper radiation thermometer. As a result, the semiconductor wafer is hardly warped along the optical axis direction of the upper radiation thermometer even during irradiation with a flash of light, thus hardly changing the emissivity of the semiconductor wafer, so that it is possible to accurately measure the temperature of an upper surface of the semiconductor wafer.