Effects of Re-baking and Substrate Temperature on Optical Properties and Residual Stress of Ion-Assisted Deposition TiO2 Thin Film

Abstract

Titanium oxide (TiO2) thin films were prepared by ion-assisted deposition (IAD) on glass substrates at various substrate temperatures. These films were re-baked and at the temperature of re-crystallization. The effects of the stability of the films on their optical properties, residual stress and surface roughness were studied. The evolution of oxidation and the cause of the variation in the optical properties and residual stress during baking and re-baking were discussed. However, the optical constants, residual stress and surface roughness varied less in re-baking than in baking. During both baking and re-baking, at substrate temperatures of 150 °C, the extinction coefficients, residual stress and surface roughness fluctuated more than at substrate temperatures of 200 and 250 °C. These results all reveal that TiO2 films were more stable after re-baking than after baking, and it was especially useful for the IAD films deposited at substrate temperature of 150 °C.