Abstract

We have examined ion-assisted deposition (IAD) of thin films on substrates at reduced temperature (<150°C). Conventional deposition techniques typically require heated substrates (~300°C). The development of deposition techniques at reduced temperature is important for coating substrate materials that cannot be subjected to elevated temperature and for improving throughput. We have observed increased values of refractive index for optical thin films of Al₂O₃, TiO₂, and Ta₂O₆ deposited using IAD that approach those of bulk material. In addition, optical coatings of SiO₂ and MgF₂ deposited with IAD have shown improved mechanical properties compared to similar films produced without IAD. We also present results from characterizing the Raman spectra and optical scatter for these films and correlate them to IAD conditions. From these results, we conclude that the application of IAD to deposition of TiO₂ at low temperature promotes the growth of crystalline structure in the film with a corresponding increase in optical scatter.

© 1987 Optical Society of America