The stress in dry thermal SiO2has been studied as a function of growth temperature by measuring the curvature of thin oxidized silicon wafers at room temperature. The results show that the curvature of wafers with thin oxide layers is determined by stress in the back-side SiO2. Anin situanneal at the growth temperature leads to relaxation of the initial compressive stress. The stress in the oxide was found to be very sensitive to water content.