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.

Design and Implementation of Wide-Angular Universal Broadband Visible Antireflection Coating for Various Substrates

“…In this study, the residual stress f in the wide-angular universal vis AR coating was measured with a phase shifting Twyman-Green interferometer and a phase reduction algorithm. [19][20][21][22][23][24][25][26][27][28] An approximate 1 nm thick Nb film was deposited on the top surface of the wide-angular universal vis AR coating by sputtering deposition in order to reflect the measured laser light. Figures 9(a onto a BK7 disk-shaped glass substrate before and after deposition.…”

Modulating the Residual Stress of Ion-Assisted TiO2Films during Annealing with Film Thickness and Substrate Temperature

“…Second, typically the annealing process can re-oxidize and reduce the residual stress for the films. Hence, at a film thickness of 270 nm, the films will relax their compressive stress by losing oxygen at annealing temperatures of 100 to 200 C, but the residual stress will again increase by recapturing the oxygen at annealing temperatures of 200 to 300 C. 27,28) Anyway, at annealing temperatures of 300 C the film will re-crystallize, and the residual stress became larger than before. The crystalline results were measured by XRD for x3.3.…”