Ion Implantation

Mössbauer Spectroscopy on Fe Impurities in Si Materials

“…Mössbauer spectroscopy appears to be ideal to characterize Fe impurities in Si crystal [6][7][8][9][10]. Recently, we have performed a series of the experimental investigations [10][11][12][13][14][15][16][17][18][19][20] using Mössbauer spectroscopy on Fe impurities in p-type and n-type Si materials such as single crystal Si, multi-crystal line (mc) Si wafers, and even mc-Si solar cells, the results are appealing that we need a new picture for Fe impurities in Si materials: the Fe impurities in the Si matrix exist not only on the interstitial sites with Fe int 0/+ and Fe int + -Bpair, but also on a higher charge state of Fe int 2+ associated with defects as well as on the substitutional sites with Fe sub 0 and Fe sub -. Furthermore, these components are found to transform each other in the Mössbauer spectra by changing experimental conditions such as temperature, external voltage, electron or light irradiation, and external stress as well as by changing the Fermi level, carriers and their concentrations, and the device structures in the vicinity of 57 Fe probes.…”