| 摘要 |
An apparatus for measuring the thickness of a layer of material, for example a semiconductor wafer, wherein the material of the layer has a property that allows radiation to be transmitted therethrough, which comprises: means (23,70) for deforming the layer of material (24) into a reflective condenser; means (10) for irradiating the front surface of the deformed layer of material with monochromatic radiation, wherein the monochromatic radiation is reflected from the front and rear surfaces of the deformed layer of material having characteristics that correspond to the thickness of said layer of material; means (30) for receiving the reflected monochromatic radiation and for detecting the characteristics; and means (36) for comparing the detected characteristics of the received reflected monochromatic radiation with a set of reference characteristics that correspond to known thicknesses and for providing an output that corresponds to the thickness of the layer of material. <IMAGE> |
