Nonmonotonic variations in the concentration of the donor-and acceptor-type radiation defects in silicon irradiated with low-intensity fluxes of β particles

Influence of low-intensive beta-irradiation on phase transformations in silicon at microindentation

“…Interest in investigations of low-intensive irradiation is caused by the qualitative difference of their manifestation compared with the effects induced by intermediate or strong physical fields [1][2][3][4][5]. One of the characteristic features of low-dose effects is a nonmonotonic dependence of the effect magnitude on the dose.…”

10.1007/s11451-008-1006-3

“…We can conventionally separate three main stages of the beta-induced variation in the microhardness H (the first maximum of softening, the intermediate recovery of the microhardness to the initial value, and the repeated softening), so that particular complexes of secondary defects dominate at each stage. The data obtained by independent methods (the synchronous testing of the microhardness, the measurement of the deep-level transient spectra, isochronal annealing of the samples at the characteristic stages of irradiation, and investigation of the dependence of the rate of relative change in the microhardness on the irra-diation intensity) made it possible to separate several types of radiation-induced defects responsible for the above stages of the variation in the microhardness H [5,7]. Specifically, the complexes composed of two vacancies, an oxygen atom, and a carbon atom, i.e., V 2 -O-C ( K center), are responsible for the first maximum of softening; the divacancies V 2 and/or complexes consisting of two carbon atoms (C i -C s ) dominate at the stage of the intermediate recovery of the microhardness; and the stage of the repeated softening is associated with the accumulation of the complexes V -O ( A center) and/or C i -O i (the indices i and s indicate that the atoms are located at interstices and sites of the crystal lattice, respectively).…”