A chemical solution approach to epitaxial metal nitride thin films

The growth of epitaxial cubic TiN metastable cubic AlN, and solid solution Ti_1-xAl_xN films with smooth surface morphologies from polymer-assisted deposition (PAD). The precursors for the growth of TiN, AlN, and Ti_1-xAl_xN films were prepared using aqueous solutions of Ti and Al bound to polymers PEI and EDTA. Ultrafiltration was carried out by repeated Amicon filtration, which retains the high molecular weight polymer with bound metal atoms, while allows any low molecular weight. The titanium solution tetrachloride was added to a solution containing 1g PEI, 1g EDTA, and 30 mL water. XRD was used to characterize the crystallographic orientation of the films. The surface morphology and surface toughness of the films was analyzed by TEM. It was observed that the room temperature electrical resistivity of the Ti_1-xAl_xN films increases exponentially with increasing Al contents, while the optical transmittance decreases with increasing Ti content.