AMORPHOUS ZN3P2 THIN-FILMS GROWN BY REACTIVE RF-SPUTTERING

Thin zinc phosphide films were grown by reactive radio frequency sputtering of pure zinc in a phosphine-containing argon atmosphere. The influence of the deposition parameters and the substrate on film composition and structure was investigated. A prominent change in the growth was noticed between deposition at room temperature and at higher temperatures owing to the high vapor pressure of zinc. A range of the r.f. power density exists for which the system is self limiting for substrate temperatures above 100-degrees-C. In this regime the phosphine mass flow is the rate limiting quantity, and the growth of non-crystalline and polycrystalline stoichiometric Zn3P2 films is possible over a large range of r.f. power density.