Secondary electron emission in nanostructurated porous

G. D. RUANO; J. FERRÓN; R. R. KOROPECKI

Puerto Iguazú- Misiones- Argentina

Simposio; XIX Latin American Symposium on Solid State Physics; 2008

We studied the reversible reduction induced by ion bombardment of the secondaryelectron emission (SEE) yield. This effect has been modeled as due to changes indynamically sustained dipoles related with ions and electrons penetration ranges. Suchcharge configuration precludes the escape of electrons from the nanoporous silicon, makingthe SEE dependent on the flux of impinging ions. Since this dipolar momentum dependson the distance separating the charged regions, as well as on the electric conduction of theporous medium, in order to gain information about these effects we performed experimentstailoring both these properties. By changing the mass (He+ and Ar+ ) and impinging ionenergy (1-5keV) we vary the ion range and therefore the charge separation in the dipole. Onthe other hand, by controlled oxidation of the nanoporous structure we are able of changingthe conduction features of the sample. FT-IR and Auger electron spectroscopy were used tocharacterize the oxidation degree of the samples at different depth scales