METHOD AND DEVICE FOR MEASURING THE THICKNESS OF A LAYER

摘要

The present invention is to a method for measuring the thickness of a layer on an object during a layer-depositing process, and a device by which the method can be realized. In the method, a diffraction object having at least two opposing diffracting limits at a known spacing, is positioned in such a way that a layer is deposited or absorbed at the diffracting limits of the diffraction object, whose thickness of layer has a known relationship with the thickness of the layer on the object. The diffracting limits of the diffraction object are projected by a coherent light pencil on a detection surface. The local intensity distribution, which is induced by diffraction on the detection surface, is detected and computed from the intensity distribution of the thickness of the layer. The method permits the detection of the thickness of thin layers during the layer-depositing process independently of the parameters of the material and with a high precision.