Stimulated desorption by surface electron standing waves

The total electron-stimulated desorption yield of Cl+ ions from the Cl-term inated Si(lll) surface is shown to exhibit fine-structure oscillations as a function of incident electron beam direction. We demonstrate that this fin e structure is consistent with quantum-mechanical scattering and interferen ce of the incident electron. Comparison of experimental data to a qualitati ve theory reveals the site of the excitation responsible for desorption, an d the ground-state atomic bonding geometry of the desorbate. The data are c onsistent with desorption initiated by an excitation localized on the Si at om bonded to Cl. [S0031-9007(99)08922-X].