Nucleation and growth of thin film zirconia using pulsed-pressure metal-organic chemical vapor deposition

Zirconia films deposited on silicon (100) substrates using pulsed-pressure metal-organic chemical vapor deposition (PP-MOCVD) with zirconium n-propoxide (ZnP) Zr(OC3H7)4 were dense and fully crystalline for substrate temperatures of 500-700°C. Film thicknesses ranged from 40 to 815 nm thick, measured after growth using ellipsometry and scanning electron microscopy (SEM). Growth rates were achieved between 0.1 mum/hr and 1 mum/hr at 500°C and 700°C, respectively. Transmission electron microscopy (TEM) and x-ray diffraction (XRD) indicated an average grain size of 10 to 20 nm. There was a random orientation of cubic/tetragonal zirconia at the highest experimental temperature of 700°C.; SEM and atomic force microscopy (AFM) was used to characterize island height of discontinuous films in the initial stages of growth where defects in the substrate caused preferred nucleation of isolated particles. At later stages of growth, the average surface roughness of continuous films was 30 nm, which revealed a more uniform growth had developed. A growth model is proposed and optimal growth conditions are suggested for targeted microstructures of ZrO2 films.; Zirconia films were also processed using a sol-gel spin-coating method with zirconium n-propoxide (ZnP) Zr(OC3H7)4 precursor. An evaluation between PP-MOCVD and sol-gel zirconia films derived from the same precursor reveals similar microstructures and grain sizes. Some of the sol-gel films had issues with carbon impurities, film cracking and pores, all issues non-existent in the PP-MOCVD films. The processing time for thicker films is relatively faster for the PP-MOCVD method.