Chemical vapor deposition of HfO2 films on Si(100)

Abstract

HfO 2 films were grown on Si(100) by chemical vapor deposition as an attempt to develop an industrially straightforward gate dielectric deposition process. During deposition at ∼400 °C the decomposition of the hafnium-tetra-tert-butoxide Hf(C4H9O)4 precursor provides sufficient oxygen to produce a stoichiometric HfO2 film. Medium energy ion scattering, high resolution transmission electron microscopy, atomic force microscopy, and ellipsometry were used to identify the structure and composition of the film and its interface to the Si substrate. Local crystallinity in the films increased significantly with annealing. Capacitance–voltage and current–voltage methods were used to characterize the electrical properties of simple capacitor structures. When grown on high quality ultrathin oxides or oxynitrides, the deposited films displayed very good physical and electrical properties.