Publications (2)1.65 Total impact
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Article: Spreading resistance and compensation of charge carriers in ferromagnetic silicon implanted with manganese
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ABSTRACT: Profiles of impurity distribution and spreading resistance have been studied in the layers of ferromagnetic silicon obtained by implantation of Mn (or Co). Standard wafers of n- and p-Si with a high or low electrical conductivity were implanted with Mn ions with the dose (1−5) × 1016 cm−2. It is found that, as a result of postimplantation annealing in vacuum for 5 min at 850°C, Mn manifests itself as an amphoteric impurity and compensates acceptors in high-resistivity p-Si and donors in low-resistivity n-Si. It is shown that only an insignificant fraction of Mn ions (1–2%) is electrically active and is involved in compensation. The magnitude of compensation is used to determine energies of the levels E c − 0.12 eV for n-Si and E v + 0.32 eV for p-Si; these levels are attributed to Mn ions at interstitial sites in the silicon crystal lattice, i.e., (Mn i )−/0 and (Mn i )+/++, respectively.Semiconductors 05/2012; 44(1):28-31. · 0.63 Impact Factor -
Article: Structure, electrical and magnetic properties, and the origin of the room temperature ferromagnetism in Mn-implanted Si
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ABSTRACT: The structure and the electrical and magnetic properties of Mn-implanted Si, which exhibits ferromagnetic ordering at room temperature, are studied. Single-crystal n- and p-type Si wafers with high and low electrical resistivities are implanted by manganese ions to a dose of 5 × 1016 cm−2. After implantation and subsequent vacuum annealing at 850°C, the implanted samples are examined by various methods. The Mn impurity that exhibits an electric activity and is incorporated into the Si lattice in interstitial sites is found to account for only a few percent of the total Mn content. The main part of Mn is fixed in Mn15Si26 nanoprecipitates in the Si matrix. The magnetization of implanted Si is found to be independent of the electrical resistivity and the conductivity type of silicon and the type of implanted impurity. The magnetization of implanted Si increases slightly upon short-term postimplantation annealing and disappears completely upon vacuum annealing at 1000°C for 5 h. The Mn impurity in Si is shown to have no significant magnetic moment at room temperature. These results indicate that the room temperature ferromagnetism in Mn-implanted Si is likely to be caused by implantation-induced defects in the silicon lattice rather than by a Mn impurity.Journal of Experimental and Theoretical Physics 04/2012; 109(4):602-608. · 1.03 Impact Factor
