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Formation of A-centres and divacancies in silicon p + -n-n + structures was investigated for 4 MeV electron irradiation in the low-intensity range of 10 11 -5 × 10 12 cm −2 s −1 . It is shown that the introduction rates of both A-centres and divacancies increase with intensity in this range and then saturate at intensities above 10 12 cm −2 s −1 . Using the data from the literature the introduction rates of these defects are discussed in a wide range of intensities of electron irradiation of 10 11 -10 15 cm −2 s −1 , indicating a consistent role of carbon interstitial atoms and electron-enhanced migration of Si self-interstitials in the observed behaviour of introduction rates.

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The relaxation kinetics of photoconductivity in neutron-doped silicon (NDS) of the p-type is discussed. It is found that the relaxation process in the compensated p-Si differs from that in the reference p-Si sample. The difference is explained on the basis of concept of different micrononuniformity of the material conductivity. A method based on studying the dependences of charge-carrier mobility on annealing time is developed for determining thermal annealing of structural defects.Silicon is known as a semiconductor material most extensively employed in electronics, which imposes stringent requirements upon its properties and characteristics. In particular, accumulation of thermal and radiation defects in silicon in most cases results in the occurrence of compensating centers. If the concentration of these centers becomes comparable with the initial charge-carrier concentration, electrophysical and photoelectrical properties of the material undergo significant changes. The majority of researchers [1, 2] believe that the photoelectrical properties of the compensated material depend on the type of impurity centers. Other researchers [3][4][5] consider that these properties mainly depend on the potential barriers between high-resistance and low-resistance regions. In so doing, the effect of the deep impurity centers and potential barriers between the p -and p + (or n -and n + )-regions on the electrophysical properties of the material is poorly understood.This work is aimed at studying the effect of conductivity micrononuniformity on the conductivity kinetics in silicon compensated by phosphorous atoms.Silicon of the р-type with ρ = 1-100 Ω⋅cm was used as an initial material. Silicon was doped with phosphorous impurity (P) using a nuclear reaction 30 Si (n, γ) 31 Si → 31 P +β − (NDS) in a VVR-SM nuclear reactor at the thermal neutron intensity ∼1⋅10 14 cm -2 [6]. In this case, the concentration of introduced phosphorous can be calculated by the following formula:where Ф = I·t is the flux of slow neutrons, cm -2 , I is the flux density of slow neutrons, cm -2 ⋅s -1 , and t is the irradiation time, s. Radiation defect annealing performed at a temperature of ∼1270 K in the air during ∼30 min was followed by slow cooling at the rate 5-10 deg/min. Ohmic contacts were produced by soldering an Sn+In (50 + 50%) alloy to р-Si at ∼400 K. The electrophysical parameters of doped silicon are summarized in Table 1.