Localisation and identification of recombination-active extended defects in crystalline silicon by means of focused ion-beam preparation and transmission electron microscopy

This paper reports on the localisation of extended defects related to the co-precipitation of transition metal impurities in silicon and their preparation for subsequent analysis using techniques of transmission electron microscopy (TEM). Two approaches are described, i.e. (i) localisation of recombination-active defects by light-beam induced current followed by preferential chemical etching and TEM sample preparation using focused-ion beam (FIB), and (ii) the replacement of the chemical etching by in situ Ga+ irradiation in the FIB system. The former technique is successfully applied to copper-rich precipitate colonies in silicon whereas the latter proofs to be the superior approach for nickel-rich particles. Structural and chemical analyses using TEM techniques are described for both cases (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)