Electron-Stimulated Modification of Si Surfaces

Scanning tunneling microscopy studies show significant structural modifications that involved atom desorption and displacement following mild irradiation by electrons of 90–2000 eV. For Sis111ds7 3 7d, adatom layer vacancies increased monotonically with incident energy. For Sis100d-s2 3 1d, irradiation produced dimer vacancies, and ad-dimers as Si atoms transferred to the terrace. The modification processes are tied to the energy distribution of electron-hole and electron attachment states achieved by inelastic cascade scattering. Hence, beams previously believed to be benign induce surface structural modifications. [S0031-9007(99)08389-1]