THE PRODUCTION OF TITANIA THIN-FILM WAVE-GUIDES BY DC REACTIVE MAGNETRON SPUTTERING

The production of thin optical waveguides with a stepped refractive index profile requires the deposition of a thin film with a high refractive index and low optical loss. This is often difficult to achieve using PVD techniques due to non-stoichiometry and the presence of voidage in the film. Amorphous titania thin films have been produced using the dc reactive magnetron sputtering of titanium. Film modification using ion bombardment induced by rf bias has been shown to yield a significant improvement in optical performance. Films have been characterised using ellipsometry and prism-coupled waveguiding. Refractive indices in the range 2.2-2.6 have been achieved. These compare well with the expected values for bulk material.