Electrically active defects induced by electron irradiation in Czochralski-grown Si crystals with low C content (NC≤2 x 1015/cm3) were studied by means of Hall effect measurements, deep level transient spectroscopy and high-resolution Laplace deep level transient spectroscopy. It was found that in n-type C-lean Czochralski-Si irradiated at room temperature a center with an acceptor level at Ec-0.11eV (E0.11) was one of the dominant radiation-induced defects. This center was not observed after irradiation in Czochralski-Si crystals with NC> 1016/cm3. The E0.11 trap anneals out at 100 to 130C, with an activation energy of 1.35eV. In p-type Czochralski-Si crystals with low C content and B (NB ≤ 2 x 1014/cm3) one of the dominant radiation-induced defects was found to be a bistable center with an energy level at Ev+0.255eV (H0.255). It was inferred from the analysis of temperature dependences of electron occupancy of this level that it was the E(0/++) level of a defect with negative Hubbard correlation energy (negative U). The activation energy for hole emission from the doubly positively charged state of the H0.255 center was determined as 0.358eV from LDLTS measurements. It was argued that the E0.11 and H0.255 energy levels were related to a complex incorporating an O dimer and Si self-interstitial.

Electrically Active Radiation-Induced Defects in Czochralski-Grown Si with Low Carbon Content. V.P.Markevich, L.I.Murin, S.B.Lastovskii, I.F.Medvedeva, B.A.Komarov, J.L.Lindström, A.R.Peaker: Journal of Physics - Condensed Matter, 2005, 17[22], S2331-40