Effects of the surface deposition of nitrogen on the thermal oxidation of silicon in O/sub 2

Abstract

Nitrogen was deposited on the surface layers of Si(100) by ion implantation at a very low energy (approximately 20 eV), at fluences between 1 and 1031014 cm-². The samples were thermally oxidized in dry O2 at 1050 °C, and the areal densities and profiles of N and O were determined by nuclear reaction analysis and narrow nuclear resonance profiling, evidencing that: (i) the retained amounts of N just after ion beam deposition stayed in the range between 0.3 and 731014 cm-²; (ii) the oxide growth is influenced strongly by the presence of nitrogen, the thickness of the oxide films (which remained between 4 and 30 nm) decreased with the increase of the areal density of nitrogen; (iii) N is partially removed from the system as oxidation proceeds. These observations are discussed in terms of current models for the thermal growth of silicon oxide in the presence of N.