Control of the chemical reactivity of a silicon single-crystal surface using the chemical modification technique

A technique is developed to control the chemical reactivity of a silicon single-crystal surface through chemical modification with atomic hydrogen. The reactivity of the reconstructed single-crystal surface prepared by high-temperature treatment in an ultrahigh vacuum is significantly decreased by capping the dangling bonds of top-layer silicon atoms with hydrogen atoms. The Si—H bonds on the hydrogenated surface are found to be much more stable against oxidation than the Si—Si back bonds. The hydrogen-passivated silicon surface is reactivated by electron beam irradiation. An ultrathin oxide layer pattern can be prepared using preferential oxidation of the area reactivated by a focused electron beam.