Deposition of Potassium Niobate Thin Films by Metalorganic Chemical Vapor Deposition and their Nonlinear Optical Properties

Ferroelectric potassium niobate thin films have been deposited by conventional, low pressure metalorganic chemical vapor deposition on several types of oxide substrates. The films were epitaxial with a c-axis orientation normal to the substrate. Atomic force microscopy revealed a surface roughness of 1 - 4 nm. Transmission electron microscopy showed the film/substrate interface to be semi-coherent with lattice misfit accommodated by misfit dislocations. The nonlinear optical properties of the KNbO3 films were measured by a transmission technique. The room temperature, effective second order nonlinear coefficient was 13 pm/V.