Temperature Dependent Electron Beam Induced Current Study of Defects in Silicon

Abstract

A new computer-aided electron beam induced current system was developed which makes it possible to obtain two-dimensional mapping of the absolute magnitudes of electron beam induced current signals over the temperature range 15 K-400 K. Electronic states of defects in cast silicon and deformation-induced dislocations in float-zone silicon were investigated from the analyses of temperature dependencies of electron beam induced current contrasts of the defects measured with the system. Electron beam induced current active defects in cast Si were identified to be Fe impurity atoms or Fe-B pairs incorporated at the dislocation core depending on the cooling rate of a crystal. Dislocations in float-zone silicon were shown to have an energy leve1 for carrier recombination in the lower half of the band gap.