LASER INTERFEROMETRY IMAGING PROCESS AND LASER INTERFEROMETER

摘要

A laser interferometry process for etching thin layers, in which a layer to be examined is irradiated with a laser and the intensity of the reflected laser beam is determined and analysed. The reflected laser beam is composed of a beam which is reflected by the top surface and a beam which is reflected by the lower boundary surface of the layer to be examined. The laser beam scans a determined area of the layer to be examined and the intensity of the reflected laser beam is entered in a data processing system able to reproduce the information about the layer to be examined. An imaging laser interferometer comprises a modulator for deflecting the laser beam, a detector for the reflected laser beam and a data processing system for processing the signals of the detector.