The electrical properties and epitaxial growth of LiNbO3 films by the MOD process

Lithium niobate films with grain sizes of 85 to 300 nm were prepared by the metallo-organic decomposition process on (110) sapphire substrates. The films were crack-free for single layer-fired thicknesses of 250 nm or less and had good transparency for grain sizes of 150 nm or less. Near 100% preferred (110) grain orientation was achieved by carrying out the thermal processing at a low oxygen partial pressure, and the films could be reoxidized without affecting the preferred orientation. The dielectric constants and dissipation factors were measured as a function of frequency for two different grain size LiNbO ₃ films, and the divergence from single-crystal results for small grain size films is explained on the basis of interfacial polarization