Chemical Stability of SC1-Cleaned Hydrogen Terminated Si(100) Surfaces

Abstract

ABSTRACTSurface contamination and chemical stability of hydrogen terminated Si(100) surfaces have been studied using Fourier Transform Infrared Attenuated Total Reflection (FT-IR-ATR) spectroscopy and X-ray Photoelectron Spectroscopy (XPS). Hydrogen terminated Si(100) is obtained by removing the chemical oxide, formed in a low-concentration-NH4OH SC1 clean, in various HF based solutions. Using standard cleaning and loading conditions, we find a direct correlation between surface roughness and the amount of adsorbed C contamination. Oxidation during water rinsing and wafer loading observed by both FT-IR-ATR and XPS indicates that dihydride terminated silicon atoms are preferentially oxidized. Optimizing the water rinse and wafer loading conditions reduces total atomic concentration of C, O, and F surface contamination from 20–30 at.% to less than 6 at.%. These clean surfaces enable XPS-identification of the Si-Hx components of the Si 2p core-level spectra as well as estimation of the relative surface concentration of Si-Hx and contamination species.