Production and evaluation of ZnS thin films by the MOCVD technique as alpha-particle detectors
Abstract Zinc sulphide thin films are deposited on several substrates such as glass, quartz, silicon, Teflon and Mylar. The chemical reaction of hydrogen sulphide with dimethylzinc is utilised for the deposition process. The optimum working conditions (deposition rate versus flow rate, temperature and pressure) are obtained. The acquired films are characterised and the films are examined for alpha-particle sensitivity. In general, the deposited films have very good adhesion to the substrate surfaces. X-ray diffraction data indicates that the films have a sphalerite structure with (111) preferred orientation. Rutherford backscattering spectrometry and electron microprobe analysis data show that films are stoichiometric and relatively free of impurities. It seems that the intrinsic defect concentration in the deposited film is insufficient to make the self-activated ZnS film an efficient alpha-particle counter.