|
Tantalum oxide (TaO1+x) films were prepared by radio frequency (RF) amgnetron sputtering method at different chamber opressure and Ar/O2 ratio. The film was then modified by a 800℃ heat treatment and microwave oxygen oplasma to transform to Ta2O5 The crystallinity, morphology and stoichiometric ratio of the films was investigated by x-ray diffraction, scanning electron microscope (SEM), atomic force microscope (AFM) and Auger electron spoectroscopy (AES), respectively. the electrical and optical properties of the films subjected to different treatment were also measured. the tantalum oxide films with best electrical performance was prepared at 6 mTorr sputtering pressure and 14.3% oxygen ambient followed by microwave oxygen plasma treatment. It had the breakdown current density ８×10-4 A/cm2 at the electric field 8.1 MV/cm. The capacitance of tantalum oxide films was 729 pF and dielectric constant was 30.7. Experimental results indicated taht microwave plasma treatment only modified the structure near film surface. The stochiometry fo the film remained TaO1+x regardless of the following modification process, as indicated by x-ray diffraction study.
|