The non-Arrhenius temperature dependence observed in the charge-to-breakdown data in thin oxides is related to the temperature dependence of the defect buildup in the same films. For each temperature, this defect buildup is studied as a function of the defect generation probability and the total number of defects at breakdown. Each of these quantities is shown to have its own unique temperature dependence, which when combined gives the results observed for the charge-to-breakdown data. As the oxide layers are made thinner, the temperature dependence of the defect generation probability dominates these observations. © 1999 American Institute of Physics.