High-pressure H2O vapor heating used for passivation of SiO2/Si interfaces

High-pressure H2O vapor heating was applied to oxidation of SiOx (x < 2) fi lms formed on silicon substrates at room temperature by thermal evaporation in vacuum, in order to improve properties of SiOx/Si interfaces for passiv ation of silicon surfaces. The SiOx films were oxidized with an activation energy of 0.035 eV. The spin density of unpaired electron decreased from 2. 3 x 10(17) to 1.4 x 10(15) cm(-3) by the heat treatment at 260<degrees>C wi th 2.1 x 106 Pa H2O vapor for 3 h. The surface recombination velocity for e xcess carriers decreased from 405 (as deposited SiOx film) to 13 cm/s. Ther e was no change in the surface recombination velocity after keeping the sam ples at an atmospheric pressure and at room temperature for 8000 h. Suitabl e passivation of silicon surface was achieved by simple heating with high-p ressure H2O vapor at low temperature. (C) 2001 Elsevier Science B.V. All ri ghts reserved.