Enhanced sputtering from the F/Si(100) surface with extraction of the surface bond direction

Area of Science:

• Surface science
• Atomic and molecular physics
• Materials science

Background:

• Understanding ion-surface interactions is crucial for materials modification and analysis.
• Fluorine adsorption on silicon surfaces is relevant for semiconductor processing.

Purpose of the Study:

• Investigate the ionization and desorption of fluorine atoms on a Si(100)-2×1 surface induced by slow, highly charged ions.
• Elucidate the mechanism of fluorine ion (F+) formation and emission.

Main Methods:

• Experimental study using slow, highly charged ion bombardment of a F/Si(100)-2×1 surface.
• Analysis of F+ ion yields and their angular distribution.
• Theoretical modeling based on the classical over barrier model.

Main Results:

• Slow, highly charged ions exhibit a high efficiency for ionizing fluorine atoms.
• F+ ion yields scale with the cube of the incident charge.
• F+ ions are emitted along Si-F bond directions, displaying fourfold symmetry.
• The kinetic energy of highly charged ion-induced F+ ions is lower than that of electron-stimulated F+ ions.

Conclusions:

• Charge transfer from F 2p electrons, explained by an extended classical over barrier model, triggers F+ formation.
• The observed symmetry and yield dependence provide insights into the ion-surface interaction dynamics.
• Highly charged ion-induced desorption offers a distinct pathway for fluorine removal from silicon surfaces.