Abstract
It has been shown that under accelerated stress at relatively low voltage thin gate oxides are subjected to the phenomenon of progressive breakdown (BD), which consists in a progressive growth of the BD spot. In this work, we investigate the conduction mechanisms of the BD spot through the measurement of the I-V characteristics using carrier separation coupled with modelling based on the concept of either co-tunneling or tunnelling through a thinned oxide region. These models are compared to direct TEM observations.