Silicon surface passivation by atomic-layer-deposited Al2 O3 facilitated in situ by the combination of H2 O and O3 as reactants

Abstract

We investigate the effect of O3 and H2O oxidant pre-pulse prior to Al2O3 atomic layer deposition for Si surface passivation. Interfacial oxide SiOx formed by the O3 pre-pulse is more beneficial than that by H2O to a high level of surface passivation. The passivation of thinner H2O–Al2O3 films is more improved by this O3 pre-pulse. O3 pre-pulse for 10 nm H2O–Al2O3 reduces saturation current density in boron emitter to 18 fA cm–2 by a factor of 1.7. Capacitance–voltage measurements reveal this interfacial oxide plays a role of decreasing interface trap density without detrimental effect to negative charge density of Al2O3. (© 2014 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)