Sputter-induced trap states at oxidized and grafted silicon surfaces: A comparative study

This paper analyzes the role of sputtering geometries on the conduction mechanism of metal–insulator–semiconductor devices where the insulating film is either SiOx or a grafted organic (sub)monolayer. The current–voltage characteristics were analyzed and correlated to the presence of traps in the band gap. The most influential defect was found to be related to interstitial Si (Sii). We will show that its deactivation moves the Fermi level towards other defect/impurity levels depending on both the insulating layer and the deposition geometry. Sii density decrease is observed when samples are less exposed to sputtered particles and radiation flow, although major effects are also correlated to the degradation of the organic monolayer upon sputtering.