Electron spin resonance was used to study the neutron transmutation doping of Si crystals enriched with 30Si isotope: P donors and radiation defects produced in the course of transmutational doping were observed. The electron spin resonance signals related to the P uncontrolled impurity in 30Si before transmutational doping (the P concentration was about 1015/cm3) and P introduced by neutron irradiation with doses of 1019/cm2 and 1020/cm2 (the P concentrations were 5 x 1016 and 7 x 1017/cm3, respectively) were studied. As a result of drastic narrowing of the P electron spin resonance lines in 30Si, the intensity of lines increased appreciably, which made it possible to measure the P concentration in the samples with a small volume (down to 10−6/mm3). The methods for determining the concentration of P donors from hyperfine structure in the electron spin resonance spectra of isolated P atoms, exchange-related pairs, and clusters that consist of three, four, and more P donors were developed. In the region of high concentrations of P donors, in which case the hyperfine structure disappears, the concentration of P donors was estimated from the exchange-narrowed electron spin resonance line.

Specific Features of Transmutational Doping of 30Si-Enriched Silicon Crystals with Phosphorus - Studies by the Method of Electron Spin Resonance. P.G.Baranov, B.Y.Ber, O.N.Godisov, I.V.Ilin, A.N.Ionov, A.K.Kaliteevskiĭ, M.A.Kaliteevskiĭ, I.M.Lazebnik, A.Y.Safronov, H.J.Pohl, H.Riemann, N.V.Abrosimov, P.S.Kopev, A.D.Bulanov, A.V.Gusev: Semiconductors, 2006, 40[8], 901-10