Sputtering condition effect on structure and properties of LiNbO3 films

Polycrystalline LiNbO3 films were grown on various substrates by the radio-frequency magnetron sputtering (RFMS) method and ion-beam sputtering (IBS) method at different sputtering conditions. Films formed on the substrates situated within erosion zone (plasma effect) manifested textured structure. When plasma effect became insignificant only LiNbO3 films with random size orientation were formed during the RFMS process and IBS process with an increase in the size of the crystallites. Reactive gas pressure as part of plasma effect has a profound effect on the films’ properties. When gas pressure was increased greatly, grain size declined two fold and the average surface roughness of the grown films doubled. At the higher gas pressure Li-poor phase LiNb3O8 appeared along with LiNbO3 during the growth process. As a result, the film texture disappeared. Single phase LiNbO3 films with two-axes (epitaxial) texture are formed on (111)Ag epitaxial film during the RFMS process at the ion assisted conditions.