Berlin 2014 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
P: Fachverband Plasmaphysik
P 21: Plasma Technology II
P 21.5: Talk
Thursday, March 20, 2014, 12:00–12:15, SPA HS201
Reactive magnetron co-sputtering from In and Cu(Ga) targets in Ar:H2S or Ar:H2Se: poisoning mechanisms of the target and influences on the discharge voltage — •Jonas Schulte and Klaus Ellmer — HZB Berlin
The reactive sputtering process from In and CuGa targets in dependence of the reactive gas content cRG (H2S or H2Se), has been investigated in order to achieve a better understanding for the process to enable reproducible depositions of Cu(In,Ga)(S,Se)2 absorber layers for thin film solar cells. In comparison to the basic Berg model of reactive sputtering processes and to detailed investigations of reactive sputtering processes in O2 and N2 by other groups, it was tried to relate changes of the discharge voltage Vdis , while applying a constant target power, to changes of the ion induced secondary electron emission (ISEE) coefficient of the target surface and hence the target poisoning mechanisms. For both targets, a clear tendency for an increasing Vdis for increasing cRG was observed, which is very similar for the case of H2S or H2Se as reactive gases. This could be, however, not related to a change of the ISEE coefficient, since measurements of the discharge voltage of a sulfurized target surface shortly after reigniting the discharge in pure Ar, show that the ISEE coefficient of the poisoned target surface is not significantly changed in comparison to the metallic surface. Furthermore, this change of the ISEE coefficient depends on the specific reactive gas content used during the poisoning procedure. This indicates the formation of different metal-S (Se) phases on the target surfaces in dependence on the reactive gas content.