Direct detection of neutral metal atoms in electron-stimulated desorption: Al from CH(sub 3)O/Al(111) - velocity distribution and absolute yield

摘要

Electron-stimulated desorption of neutral aluminum from the system CH(sub 3)O/Al(111) has been directly monitored via quasiresonant photoionization with 193 nm excimer laser light and confirmed by two-step resonant ionization, utilizing the Al 3d (sup 2)D manifold. Velocity distribution measurements for the neutral Al peak at (approximately) 800 m/s for 1 keV incident electron energy. An absolute yield of 3.2 x 10(sup (minus)6) Al atoms/electron was determined by comparison with sputtering measurements in the same apparatus. This is the first observation of electron-stimulated metal desorption from adsorbate-covered metallic surfaces.