Epitaxial growth of cubic ZnS by evaporation in ultra-high vacuum

Abstract

Ultra-high vacuum apparatus has been developed for the electron-beam evaporation of II-VI semiconducting compounds on to ionic substrates cleaved in vacuum and heated by an external infra-red lamp. Epitaxial films of cubic ZnS, free of wurtzite-structure grains and microtwins, were grown on NaCl at temperatures down to 225°C. Cleavage in an ultra-high vacuum system was essential in order to obtain films reproducibly at this temperature that were free of included grains. The effect on film structure of different types of contamination was studied.