An apparatus 100 for measuring thermal radiation in one mode of the present invention is used for detecting thermal radiation of an object 12 to be measured. The apparatus 100 is provided with: a sample cell 10 which includes the object 12 to be measured which is a liquid or an object containing liquid, and a housing part which houses the object 12 to be measured and includes one wall formed of a base 16 transmitting a wavelength of the thermal radiation; a first lens 20 formed by partially cutting a sphere so that a cross section forms a plane, wherein the sample cell 10 is arranged so that, when the base 16 is in close contact with the plane of the first lens 20, focus of a second lens is placed on at least a part of the object 12 to be measured, for example, located on the base 16, the second lens including the first lens 20 and the base 16 and used for detecting the thermal radiation through the first lens 20; a position controller 60 which controls one of the object 12 to be measured and the first lens 20 so as to be able to abut on and separate from the other in an optical axis direction; a vibrational controller 40 which allows one of the object to be measured and the first lens to vibrate with respect to the other and controls a frequency of the vibration; and a detector 70 which detects the thermal radiation through the first lens 20.

A method for coating a substrate with at least one layer. During deposition of the layer, at least one optical measuring device repeatedly determines successive measurement value pairs on the layer, each containing an emission value corresponding to the radiation power measured at a light wavelength and a reflectance value, which is also measured at a light wavelength. Actual values of a substrate temperature are calculated based on the measurement value pairs and a previously determined correction value. The actual values are used to control a temperature-control device for controlling the substrate temperature to a desired value. To improve the determination of the correction factor, during the measurement and within a plurality of measurement intervals, at least two measurement value pairs are measured and, for each of the measurement intervals, a temperature-dependent factor is determined that is used for the calculation of the correction value.

An edge radiation thermometer performs measurements before a semiconductor wafer is transported into a chamber. The edge radiation thermometer performs the measurements while the semiconductor wafer is supported by lift pins and while the semiconductor wafer is placed on a susceptor, after the semiconductor wafer is transported into the chamber. A controller calculates a reflectivity of the semiconductor wafer based on these measurement values. Then, the controller calculates an intensity of an ambient light receive by the edge radiation thermometer, based on the reflectivity and an intensity of synchrotron radiation radiated from a quartz window. Subsequently, the controller subtracts the intensity of the ambient light from an intensity of light received by of the edge radiation thermometer during heat treatment on the semiconductor wafer to calculate the temperature of the semiconductor wafer.