It was shown that photoluminescence images, taken before and after dissociation of Fe-B pairs, permitted accurate imaging of the interstitial Fe concentration across a B-doped p-type Si wafer. Such Fe images could be obtained more rapidly than with existing point-by-point Fe mapping techniques. However, because the technique was best used at moderate illumination intensities, it was important to adopt a generalized analysis that took account of different injection levels across a wafer. The technique was verified via measurements of a deliberately contaminated monocrystalline Si wafer with a range of known Fe concentrations. It was also applied to directionally solidified ingot-grown multicrystalline Si wafers made for solar cell production, which contain a detectible amount of unwanted Fe. The Feimages on these wafers revealed internal gettering of Fe to grain boundaries and dislocated regions during ingot growth.

Imaging Interstitial Iron Concentrations in Boron-Doped Crystalline Silicon using Photoluminescence. D.Macdonald, J.Tan, T.Trupke: Journal of Applied Physics, 2008, 103[7], 073710