Correlation between the electrical properties and morphology of low-pressure MOCVD titanium oxynitride thin films grown at various temperatures

Titanium oxynitride (TiNxOy) thin films were deposited by low-pressure meta l-organic CVD (LP-MOCVD) on (100)silicon, sapphire, and polycrystalline alu mina substrates. Titanium isopropoxide (TIP) and ammonia were used as precu rsors. The influence of the growth temperature, ranking from 450 degrees C to 750 degrees C, was investigated by scanning electron microscopy (SEM), a nd electrical DC measurements. Rutherford back-scattering (RBS) measurement s were used to determine the N/O ratio in the films. The surface observatio ns of the deposited films showed two morphological transitions. The resisti vity decreased with the growth temperature, while the nitrogen content incr eased. Moreover, for the highest deposition temperatures, the temperature d ependence of the resistivity revealed a transition from a semiconducting to a metallic behavior. Finally, these electrical properties were correlated with the two morphological transitions.