Oxidation-induced stacking fault rings in polished Czochralski silicon samples before and after thermal wet oxidation were investigated by use of photoluminescence imaging. Currently the standard procedure for oxidation-induced stacking fault ring detection was to expose the samples to a toxic preferential etchant, e.g. a Wright solution, after thermal oxidation. This solution primarily attacks the regions with stacking faults, allowing detection by visual inspection. Samples from the seed end of p-type Czochralski silicon ingots with resistivities of approximately 1Ohm-cm were measured by photoluminescence imaging before and after a thermal oxidation process. Subsequently, Wright-etching was performed on the oxidized samples to expose stacking faults. The lifetime variations in the photoluminescence images were correlated with the location of the rings in the preferentially etched surfaces, and good agreement was found. The results showed that for this crystal pulling process, even the photoluminescence images of unpassivated polished samples could be used to detect the oxidation-induced stacking fault ring location. The thermal oxidation at 1100C enhanced the contrast between the oxidation-induced stacking fault ring and the rest of the sample in the photoluminescence image.

Characterization of Oxidation-Induced Stacking Fault Rings in Cz Silicon: Photoluminescence Imaging and Visual Inspection after Wright etch. H.Angelskår, R.Søndenå, M.S.Wiig, E.S.Marstein: Energy Procedia, 2012, 27, 160-6