ausblenden:
Schlagwörter:
experiment VINETA
Zusammenfassung:
The formation of negative ions has attracted attention in plasma processing application like e.g. semiconductor fabrication, where negative ions can considerably effect in the etching quality. High density argon and oxygen plasmas are generated during helicon discharge in the experiment VINETA. Measurements of the negative oxygen ion concentration for different discharge scenarios will be presented. The relative concentration of negative ions is measured by Langmuir probe techniques and by laser-induced photedetachment combined with microwave interferometry. Special attention is paid to the dependence of the negative ion concentration on the gas pressure, argonadmixture, and RF power. By radially scanning the laser used for photodetachment also the radial profile of the negative ion concentration is resolved and will be compared to the radial plasma profiles.
