Passivation of SiO2/Si interfaces using high-pressure-H2O-vapor heating

High-pressure H2O vapor heating was used for the passivation of silicon surface. The thermally evaporated SiOx films formed on the silicon surface was oxidized and Si-O bonding density increased with an activation energy of 0.035 eV with increasing heating temperature upon heat treatment with 1.0 x 10(6) Pa H2O vapor. The peak wave number and full width at half maximum of the Si-O absorption band due to the Si-O-Si antisymmetric stretching vibration mode were changed to 1077 cm(-1) and 72 cm(-1), respectively. The density of silicon dangling bonds was reduced from 2.0 x 10(17)(as deposited) to 1.4 x 10(15) cm(-3) by heat treatment. The effective surface recombination velocity of the p-type silicon wafer that was coated with SiOx films was markedly reduced from 405 cm/s (as deposited) to 13 cm/s by heat treatment with 2.1 x 10(6) Pa-H2O vapor at 260 degrees C for 3 h. The interfaces retained the low recombination velocity 8000 h after keeping the sample in air. Effective field effect passivation was demonstrated using a SiOx/SiO2 double layered structure formed by the combination of thermal evaporation and heat treatment with high-pressure H2O vapor.