Cadmium Chloride Thin Films: Hydration-Dehydration

ABSTRACT

We have been using polycrystalline thin films of anhydrous cadmium chloride (CdCI2) as an electron beam positive resist for the fabrication of features in SO2- coated silicon wafers The kinetics and mechanism of the electron-beam-induced decomposition of CdCI, which is the resist reaction, have been studied in details this work required that we know the thickness and density of the film. In the ordinary way of things, film thickness and density determination is a routine matter, but CdC12 hydrate on exposure to the laboratory atmosphere, becoming CdCI2-xH2O, with a corresponding change in density and thickness. It was therefore necessary to undertake the study, which is reported here, of the dehydration of CdCl2 thin films.