Electrical and structural properties of solid phase crystallized polycrystalline silicon and their correlation to single-electron effects

Abstract

Single-electron transistors have been fabricated in solid phase crystallized polycrystalline silicon films deposited on SiO2 layers grown on silicon substrates. The single-electron transistors consist of lateral side-gated nanowires. A Coulomb staircase is observed at 4.2 K, which is fully modulated by the side-gate voltage. Two-period conductance oscillations are observed in nanowires fabricated on 10-nm-thick buried oxide layers, while single-period oscillations are observed in nanowires fabricated on 40-nm-thick buried oxide layers. The two-period oscillations are attributed to the formation of a charge layer in the silicon substrate. The single-electron effects are also studied as a function of the nanowire dimensions and annealing or oxidation treatments. The effects are correlated to the structure of the polysilicon film, characterized using transmission electron microscopy, Raman spectroscopy, and electron spin resonance analysis. These measurements demonstrate the significance of single-electron charging effects on electron transport in nanometer-scale complementary metal-oxide semiconductor systems.