On the effect of hydrogen incorporation in strontium titanate layers grown by high vacuum magnetron sputtering

Hydrogen incorporation in strontium titanate thin films grown in a high vacuum environment by rf magnetron sputtering on MgO(001) substrates was investigated by nuclear resonance analysis. The amount of hydrogen in the films is strongly affected by the growth temperature. Films deposited at or below 200 °C have a close-to-amorphous microstructure, are oxygen rich and exhibit hydrogen incorporation up to 0.08 (atomic ratio). As the growth temperature is increased to ⩾250 °C, crystalline growth of stoichiometric SrTiO3 is obtained, with a hydrogen content of 0.006. The results provide evidence that hydrogen incorporation is decisive for the composition as well as the microstructure evolution of the layers.