THERMAL-OXIDATION OF (100)SILICON IN O-2 AND CO2 AND IN EFFECT ON THESIO2-SI METAL-OXIDE-SEMICONDUCTOR PARAMETERS

(100)-oriented silicon substrates were oxidized in a mixture of oxygen and carbon dioxide at temperatures in the range 900 to 1100 degrees C . The oxidation rate was found to decrease significantly with increasi ng concentration of CO2 in O-2. The linear and the parabolic rate cons tants were extracted and their corresponding activation energies were calculated to be 48.4 +/- 2.8 and 25.4 +/- 3.0 kcal/mol, respectively. Comparison with Si oxidation in N-2/O-2 mixture revealed that CO2 not only reduces the partial pressure of oxygen but it also offers additi onal retardation to the oxide growth. Capacitance-voltage measurements on gate oxides grown in CO2/O-2 mixture showed a significant change i n metal oxide semiconductor parameters like threshold voltage, backgro und doping concentration, and interface state density when compared wi th reference metal oxide semiconductor capacitors. Capacitance-time me asurements revealed a significant degradation in the generation lifeti me for CO2/O-2 grown gate oxides.