Effect of residual stress on oxygen sensor characteristics using epitaxial YSZ thin films

Abstract

Oxygen sensor using yttria-stabilized-zirconia (YSZ) shows higher resistivity at lower temperature. The working temperature of oxygen gas sensor using epitaxial YSZ thin film deposited on (001) Si substrate was decreased drastically, e.g. 300oC. It might be the reason that thinner the film thickness reduces the internal resistivity of oxide ion conduction in YSZ. On the other hand, YSZ thin film received the residual stress by thermal expansion coefficient mismatch between thin film and the substrate. Activation energy values was calculated from the Arrenius plot of DC resistivity change along the film plane with different temperatures. There was a tendency that the activation energy slightly decreased with decrease of residual compressive stress along the YSZ thin film.