THERMAL ANNEALING OF MICRO-OXIDIZED ZINC NITRIDE SPUTTERED THIN FILMS FOR CONVERSION INTO CRYSTALLINE ZnO

Abstract

Thermal oxidation and annealing of zinc nitride sputtered films are described in this paper. Zinc nitride films were produced by the sputtering a zinc target (99.999%) in the plasma, ignited in a mixture of Ar:N2 (20:10 sccm) gas at 60 W and working pressure of [Formula: see text][Formula: see text]mbar. The films were initially micro-annealed in H2O2 solution (35[Formula: see text]vol.%) at room temperature and subsequently in ambient air in the low temperature range of 100–[Formula: see text]C. The as-sputtered and annealed films were examined using X-ray diffraction (XRD), spectrophotometer, Raman and photoluminescence spectroscopies. Annealing oxidation leads to the transformation of the cubic crystal structure of zinc nitride into wurtzite ZnO through the oxygen diffusion process. The XRD peak of (002) plane and the principal [Formula: see text] (high) phonon mode, detected for the annealed film, are clear signature on the conversion of zinc nitride film into crystalline ZnO. The sputtered annealed film showed optical transmittance of 85% and average bandgap energy of 3.28[Formula: see text]eV due to the formation of ZnO. The presented method is appealing since it provides an easy two-step route to the conversion of zinc nitride film into ZnO with p-type behavior and tunable characteristics for various optoelectronic applications.