Author/Authors :
Bohmeyer، نويسنده , , W. and Tabares، نويسنده , , F.L. and Baudach، نويسنده , , M. and Cwiklinski، نويسنده , , A. and Markin، نويسنده , , A. and Schwarz-Selinger، نويسنده , , T. and Ferreira، نويسنده , , J.A. and Fussmann، نويسنده , , G. and Loarte، نويسنده , , A.، نويسنده ,
Abstract :
The influence of nitrogen injection on the formation of a-C:H films in areas far away from the plasma as well as close to the plasma boundary was studied in the PSI-2 device for collector temperatures between 310 and 350 K. The balance between deposition and erosion determines the net growth rate. Small amounts of nitrogen (Φ(N2) ≈ Φ(CH4) ≈ 2% Φ(H2)) strongly reduce the net growth rate in H2/CH4 mixtures. While N2 injection does not influence erosion far away from the plasma it increases erosion close to the plasma boundary. The experiments show clear evidence for a scavenger effect due to the injected nitrogen. The conversion from N2 to active species takes place in the hot plasma region.
