Thin SiO2 films grown for brief oxidation times

Bulk p-type wafers prepared with HF and RCA cleaning were oxidized in an at mospheric pressure O-2 ambient with incandescent lamp heating. Minimal effe ctive oxidation times of several seconds were obtained by rapidly heating w afers at rates up to 150 degrees C/sec and then turning off lamp power just as the desired peak temperature is approached. Cooling rates vary up to ab out 80 degrees C/sec. Film thicknesses obtained by this "spike" method incr ease from 1.5 nm for peak temperature of 1000 degrees C to 3.5 nm for peak temperature of 1200 degrees C. Oxidation kinetics was studied by varying pr ocessing time from a spike to a 20-s plateau. The activation energy is 2.5 eV for 1.5 nm to 5.0 nm films. Film thickness uniformity under 1% at one st andard deviation over 150 mm wafers, equivalent to 2.5 degrees C temperatur e variation, was obtained for spike oxidation by optimizing relative power ratios to the lamps. Measurements on blanket oxidized wafers by ellipsometr y and corona-charge Kelvin surface photovoltage techniques indicate equival ent physical properties over the range of oxidation times.