Behaviour of metallic impurities at grain boundaries and dislocation clusters inmulticrystalline silicon wafers deduced from contactless lifetime scan maps

Abstract

By means of a contactless microwave phase shift technique, the minority carrierlifetime and surface recombination velocity were measured in multicrystallinesilicon wafers containing iron and chromium. The bulk lifetime can bededuced, leading to the determination of the concentration of interstitial iron[Fei ] associated with boron, after pair dissociation annealing at210 °C. It is foundthat [Fei ] is higher in the vicinity of extended defects but decreases at the defects because the ironsegregates irrespective of boron concentration and does not form pairs.