Enhancement in ultrathin oxide growth by thermal-induced tensile stress

Rapid-thermal oxide grown under the condition that a certain portion of the substrate wafer was covered by another wafer with special shape was studied. It is interesting to find that in the ultrathin oxide regime, the thickness of oxide with covered wafer is even larger than that without. Thermal-induced tensile stress is believed to be the origin of the above enhanced oxidation rate. A novel ultrathin oxide grown at a low temperature of 800°C is demonstrated. The capacitance-voltage and current-voltage characteristics of MOS capacitors with oxides grown with and without cover wafers under the same oxide thickness were compared.