Molecular Hydrogen Adsorption onto the Si(111) 7 x 7 Surface.

We have studied the adsorption of molecular hydrogen onto the Si(111) 7 x 7 surface using UHV TEM at temperatures between room temperature and 780C. We demonstrated that molecular hydrogen at 4 x 10 sup (-6) Torr dissociatively chemisorbed onto the Si(111) surface at elevated temperatures and the stable hydrogenated Si(111) surface is shown to be a strong function of temperature.