STABILITY OF ADSORBED HYDROGEN ON Si(100) UNDER CHANGES OF THE SURFACE POTENTIAL

Abstract

We study the effect of an electrostatic surface potential on the chemisorption energy of H 2 on a Si (100)2×1 surface on the basis of a set of ab initio calculations. We find a sizeable destabilization of the adsorbate, because the clean surface gains in stability compared to the H-terminated surface due to charge transfer between dangling bonds and the space charge region below the surface. We rationalize our results in terms of a simple model and discuss the possibility that potential-induced destabilization is an important ingredient in understanding STM-induced nanolithography.