METHOD FOR THE IN-SITU DETERMINATION OF THE MATERIAL COMPOSITION OF OPTICALLY THIN LAYERS, ARRANGEMENTS FOR PERFORMANCE AND APPLICATIONS OF THE METHOD

摘要

Known methods are based on the measurement of the total reflection and analyze reflections of optical radiation in the case of smooth surfaces. Therefore, they require a normalization by measurement of the reference light or other measurement of the refractive indices. As a result, they cannot be used universally; in particular they cannot be used for process control of evaporation processes. The control methods known in this field operate only qualitatively on the basis of specific characteristics in the production process. For genuine quantative regulation, however, it is essential that the components to be regulated (optical layer parameter) are also made measurable. The method according to the invention directly determines the material composition of optically thin layers and is based on an optical layer model that was derived from electromagnetic conduction theory with field resistances. The deposited layer is irradiated with preferably incoherent spectral light, preferably from a white light source, and the reflection intensities outside total reflection are detected by a spatially resolving optical detector, preferably CCD, and fed into the layer model. The characteristic functions of the layer model are fitted to the real process values and serve for numerically ascertaining the optical layer parameters from which the specific material composition can be derived.