Residual Stresses at an Oxide-Silicon Interface

Residual stresses occurring at an oxide-silicon interface are studied by measuring the bending of an oxidized silicon slice which results when the oxide is removed from one face. The stresses are independent of the orientation of the silicon surface, and over a wide range of the doping level of the silicon. Stresses increase with the speed at which the samples are cooled after the oxidation: An oxide grown in dry O2 causes larger stresses than one grown in wet O2. The stresses measured do not appear to be capable of causing considerable numbers of interface states.