Subtracted Auger electron spectra of heavily doped transition-metal impurities in Si

A spectral subtraction method of Auger valence spectra has been applied in order to analyze the changes of the valence electron states in Si: Fe and Si : Co solid solution layers. In the subtracted Auger spectra of Si : Fe solid solution layers for less than about 4%, the peak position shifted to the lower-energy region. Si 3s, 3p bands and Fe 3d one appeared to be modified by local Fe-Si chemical bonds in the Si:Fe solid solution layers for a few percent. The subtracted-spectral changes of Si : Co solid solution for 8.8% and 7.5% were associated with the drastic change of the interactions between Si and Co impurities. The Si:Co solid solution layers for less than about 5% have almost no significant interactions between Si and Co impurities. (C) 2000 Elsevier Science B.V. All rights reserved.