Measurement of VUV induced surface conduction in dielectrics using synchrotron radiation

In a plasma processing chamber, the combination of VUV (vacuum ultra-violet) flux and electric fields (either due to plasma non-uniformity or electron shading) across structures on a wafer can induce photoconduction currents in insulating dielectrics. These currents can either flow through the bulk of the dielectrics or along the surface. In this paper we report the results of our experiments on studying VUV induced surface currents. These currents, if they are large enough, would modify surface charging and hence are important to understanding, predicting and controlling plasma charging damage