A SIMPLE METHOD FOR THE RAPID MEASUREMENT OF THE THICKNESS OF ULTRATHIN METAL-FILMS

A simple method for the rapid measurement of the thickness of ultrathin metal films in the range from a few angstroems to about 100 A was developed. The method is based on measurements of the intensity of electrons backscattered by the film; primary electron with energies of the order of 10 keV were used. A good thickness resolution of at least 0. 3 A was obtained for gold. If the focused electron beam of a scanning electron microscope is used, the method has an inherent lateral resolution of the order of 1 mu m. A number of films consisting of metals with atomic numbers Z greater than equivalent to 13 were successfully analyzed. The method is applicable to films of noble metals as well as to reactive materials such as aluminum, scandium and cerium.