COADSORPTION OF HYDROGEN AND DEUTERIUM ON SI(100) SURFACES STUDIED BYELASTIC RECOIL DETECTION ANALYSIS

We have carried out coadsorption experiments of hydrogen (H) and deute rium (D) to investigate the dynamic behavior of hydrogen adsorption on Si(100) surfaces. During the experiments, changes in H and D on the s urface are quantitatively measured by an elastic recoil detection anal ysis method using a 6 MeV F3+ ion beam. In the process of H adsorption onto D-adsorbed surfaces at both room temperature and 350-degrees-C, we found that the H concentration shows a gradual increase accompanied by a gradual decrease in the D concentration. A similar result is obt ained for D adsorption onto H-adsorbed surfaces at the same temperatur es. As a dynamic behavior, substitution between the adsorbed hydrogen and the atomic hydrogen impinging upon the surface is strongly suggest ed.