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Magnetoplasticity and Diffusion in Silicon Single Crystals A. A. Skvortsov and A. V. Karizin Moscow State Technical University “MAMI,” Moscow, 107023 Russia email: [email protected] Received April 19, 2011

Abstract—The effect of static magnetic fields on the dynamics of surface dislocation segments, as well as the diffusion mobility of a dopant in silicon single crystals, has been analyzed. It has been experimentally found that the preliminary treatment of ptype silicon plates (the dopant is boron with a concentration of 1016 cm ⎯3) in the static magnetic field (B = 1 T, a treatment time of 30 min) leads to an increase in the mobility of surface dislocation segments. The characteristic times of observed changes (about 80 h) and the threshold dopant concentration (1015 cm–3) below which the magnetooptical effect in silicon is not fixed have been deter mined. It has been found that diffusion processes in dislocationfree silicon are magnetically sensitive: the phosphorus diffusion depth in ptype silicon that is preliminarily aged in the static magnetic field increases (by approximately 20%) compared to the reference samples. DOI: 10.1134/S1063776111160096

Problems in controlling the mechanical properties of diamagnetic crystals by a magnetic field (socalled magnetoplastic effects) have been actively discussed in recent years. Ionic crystals are most studied in this field [1–3]. This concerns both the first experimental observation of magnetoplastic effects in NaCl single crystals [1] and the subsequent proof of its nature [2⎯10]. Interest in these effects in various condensed media increases for both the study of magnetoplasticity phys ics and its applications, because magnetic treatment has a number of technological advantages compared to other processes (simple and cheap equipment, short treatment time, universality, etc.). The magnetoplasticity of semiconductor crystals, particular silicon, is also of current interest [2]. The matter is not in the possibility of controlling disloca tion mobility (which is confirmed experimentally in silicon [10–13] and makes it possible to clearly detect the presence of magnetically sensitive complexes of point defects and their dynamics). The problems of the formation of these dopant–defect complexes in doped dislocationfree silicon and their effect on tech nological operation such as the diffusion of a dopant are of most interest. The aims of this work are to study the magnetoplas tic effect in silicon single crystals, determination of experimental conditions of its manifestation, and the effect of preliminary aging of Si plates in the static magnetic field on the diffusion of phosphorus in them. Morgunov [14] proposed to classify the known magnetoplastic effects in diamagnets into two types, namely, dynamic (require the presence of dislocations or their motion in crystals) and static (are associated with the transformation of magnetically sensitive

complexes and do not require the presence of disloca tions or their motion in crystals). For thi