Excess Si atoms near the pyrolytic-gas-passivated ultrathin silicon oxide/Si(100) interface
Author: Yamada, Hiroshi
Source: Journal of Electronic Materials, Volume 33, Number 7, July 2004 , pp. 802-808(7)
Abstract:Number densities of Si and O atoms for 3.5-6.5-nm-thick, silicon-oxide films, grown using a recently proposed in-situ passivation method that uses a little pyrolytic N2O gas, were determined by Rutherford backscattering spectrometry (RBS). It was found that excess Si atoms relative to the stoichiometric SiO2 composition exist near the silicon oxide/Si(100) interface, and their number decreases with decreasing humidity. The decrease is remarkable for the pyrolytic-gas passivation (PGP)-grown films at a humidity of less than 1 ppb, which contrasts largely with the humidity dependence of other characteristics, such as density, device reliability, etc., and a remarkable increase can also be confirmed at the same low humidity. Therefore, it is believed that all of the humidity dependence probably has a common origin: PGP results in a reduction of the excess Si atoms near the interface as well as dehydration and causes a decrease in Si dangling bonds by making stronger N-related bonds.
Document Type: Research article
Publication date: 2004-07-01