Deep levels in β-FeSi 2/n-Si heterojunctions

Abstract

Deep levels in β-FeSi 2 /n-Si heterojunctions are investigated by deep level transient spectroscopy (DLTS) measurements. The results reveal the presence of defect states in the Si layer, located close to the interface, with activation energies from the conduction band edge ΔE 1=0.50 eV and ΔE 2=0.53 eV and capture cross-sections σ=2.4×10 -14 cm 2 and σ 2=2.1×10 -14 cm 2, respectively. Carrier depth profiles, obtained by capacitance-voltage measurements, support the existence of these deep traps. It is suggested that the deep traps originate from Fe diffused into the Si during the formation of the silicide.