The Influence of Silicon Surface Cleaning Procedures on Silicon Oxidation

Abstract

The results of experiments which demonstrate the effect of pre-oxidation cleaning of silicon on the kinetics of oxidation for 5 different cleaning procedures are reported. These cleaning treatments include simply rinsing samples as obtained from the manufacturer as well as combinations of NH4OH-H2O2, HCl-H2O2 and HF solutions. The thickness vs. time data for 1 atmosphere oxidations at 980 C is analyzed to determine oxidation rates at thicknesses of 75.0, 275.0 and 405.0nm. Varying rates calculated at low thickness indicate an effect in the initial oxidation regime due to interfacial effects. Rate differences calculated at high thickness indicate a change in oxide structure due to cleaning treatment which is substantiated by ellipsometric measurements of refractive index which indicate a change in oxide density.