Abstract: Disclosed herein is a method for producing a film of mixed yttrium and hafnium oxides, nitrides or fluorides on a substrate by an atomic layer deposition process. The process includes providing a reaction chamber containing a substrate, pulsing into the chamber an yttrium source reactant; purging the chamber with a purging material; pulsing into the chamber a co-reactant precursor; purging the chamber with a purging material (first subcycle); pulsing into the chamber a hafnium source reactant; purging the chamber with a purging material; pulsing into the chamber a co-reactant precursor; urging the chamber with a purging material (second subcycle). Each subcycle may be repeated multiple times in a super cycle.