Atomic layer deposition of (K,Na)(Nb,Ta)O3 thin films

Abstract

Thin films of complex alkali oxides are frequently investigated due to the large range of electric effects that are found in this class of materials. Their piezo- and ferroelectric properties also place them as sustainable lead free alternatives in optoelectronic devices. Fully gas-based routes for deposition of such compounds are required for integration into microelectronic devices that need conformal thin films with high control of thickness- and composition. The authors here present a route for deposition of materials in the (K,Na)(Nb,Ta)O3-system, including the four end members NaNbO3, KNbO3, NaTaO3, and KTaO3, using atomic layer deposition with emphasis on control of stoichiometry in such mixed quaternary and quinary compunds.