UBC Theses and Dissertations
Ellipsometric studies of electro-optic and ionic conductivity effects in thin oxide films Cornish, William Duncan
An automated ellipsometer was used to study three topics associated with the anodic oxide films of tantalum and niobium. The electro-optic effect was measured on tantalum and niobium oxides and was found to be quadratic. The change in refractive index upon application of a field occurred in two phases: an instantaneous change followed by a slower change. The effects on Nb₂O₅ were greater than on Ta₂O₅. The effect of ultra violet light on the two oxides was found to cause a change in the refractive index before appreciable photo-induced growth occurred. The results indicated that it was unlikely that the u.v.-induced change in refractive index occurred uniformly throughout the film. The effects of annealing and temperature are discussed in relation to the constant field current transient. The change in the refractive index during the transient was monitored with the ellipsometer.
Item Citations and Data