LOCAL THICKNESS MEASUREMENTS USING REFLECTIVITY OF X-RAYS IN THE DISPERSIVE ANGLE MODE

The multiple beam interference of parallel layers and/or the Bragg pea ks of multilayers are measured in the angle-resolved dispersive mode w ith a position sensitive proportional counter. The specimen is illumin ated by a divergent X-ray beam produced by a sealed linear focus tube. The arrangement permits either to obtain spectra in a short time and to eliminate any movement during measurement. Furthermore, this config uration has the advantage of analysing a small surface area of the spe cimen (less than 1 mm2). Consequently, a scanning of a layer or a mult ilayer is possible. Both examples concerning a deposited layer and a m ultilayer will be given, showing variation in thickness according to t he distance between the sputtering or evaporation system and the sampl e holder.