HYDROGEN INTERACTION WITH SB-TERMINATED GAAS(100) AND INP(110) SURFACES

The interaction of atomic hydrogen with InP(110) and GaAs(110) surface s terminated with a well-ordered antimony monolayer was investigated u sing spectroscopic ellipsometry and Raman spectroscopy. The characteri stic features of the surface dielectric function associated with the S b monolayer and the Raman lines from the excitation of surface vibrati onal modes disappear with increasing hydrogen exposure, indicating the etching of the Sb monolayer. No additional structure in the surface d ielectric function and no shift in the phonon frequencies were detecte d during the etching process. By comparing the experimental results wi th ab initio calculations we conclude that the etching of the Sb monol ayer starts at defect sites of the Sb monolayers and then propagates t hrough the Sb surface chains.