Investigation of silicon oxynitride and amorphous silicon \nmultilayers

Abstract

\n \nOptical (refractive index) and structural properties of silicon \noxynitride (SiON) and amorphous silicon (a-Si) multilayers grown by RF \nsputtering with thickness in the 10–30 nm range have been \nanalysed by ellipsometry and TEM. Satisfactory agreement between \nthe two techniques is obtained as regards the thickness \ndetermination of the SiON films. Disagreement with values obtained \nby the stylus method by extrapolation for the two types of layers \nis discussed. The interfaces of the SiON films are very good when \nn-type P doped Si is used as a target. They are wavy with average \nperiodicity and amplitude on the order of 50 and 2 nm, respectively, \nwhen a semi-insulating Si target is used, despite the presence of a \nbuffer layer. Hypothesis is made that P incorporation may improve \nthe reconstruction of the SiON surface.\n\n\n\n