R.f. reactive sputtering of zinc oxide films on silicon and Si-SiO sub(2)-TiN substrates

The r.f. diode sputtering ZnO films using an Ar and O sub(2) gas mixture has been studied as a function of the O sub(2) content in the sputtering gas. ZnO films are deposited onto both elemental Si substrates and those with the configuration Si-SiO sub(2)-TiN. Non-stoichiometric ZnO films are deposited by the r.f. sputtering of a ZnO target in pure Ar gas and the film resistivity ( rho = 0.1-10 Omega cm) is particularly determined by the carrier concentration (n=10 super(18)-10 super(19) cm super(-3)). The highly ordered films with a preferential (002) orientation of their fibre grains are deposited in sputtering gas containing over 50% oxygen at a substrate temperature of 300 degree C. The reactively sputtered ZnO films are optically clear (transparence 80-90%) with a band gap of 3.22 eV.