Reaction between Gas-phase Hydrogen Atom and Chemisorbed Bromine Atoms on a Silicon(001)-(2xl) Surface

摘要

The reaction between gas-phase atomic hydrogen and highly covered chemisorbed bromine atoms on a silicon(001)-(2x1) surface is studied by use of the classical trajectory approach.The model is based on reaction zone consisting of H,Br and Si atom interacting with a finite number of primary system silicon atoms,which are coupled to the heat bath.The calculations were carried out in the temperature range 300-2500 K for the gaseous H atom and 0-700 K for the surface,respectively.All reactive events occur in a single impact collision on a subpicosecond scale,following the Eley-Rideal mechanism.The reaction probability is dependent upon the gas temperature and the largest near 800 K,but it is essentially independent of the surface temperature.The reaction energy available for the product state is small,and most of the reaction exothermicity deposits in vibration and translation of the product,HBrmolecule.