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Temperature dependence of the mobility of electrons and holes in p-Si, cultivated by Czochralski method and бестигельной zone melting, after irradiation by fast neutrons reactor was considered. In the framework of the elaborated model of clusters defects the temperature dependence of the concentration of electrons and holes in silicon samples was described. It is shown that the configuration change divacancies in clusters of defects and in conducting matrix leads to increase in the height of the drift barriers and concentration long-wave phonons in conducting matrix samples of silicon.

Model of modification of basic levels of the known radiation defects in silicon and a germanium is offered. Energy of Hubbard is independent of number of electrons on radiation defect, and its size depends on base-line admixtures near-by vacancy defect. If near-by vacancy defect of the interstitial atom of oxygen is located, then energy of the negatively-charged acceptor defect is reducing on 0.06 eV, and energy of donor rises on the same size. The interstitial atom of silicon and of germanium changes the levels of defect on 0.03 eV. The atom of car-bon in the interstitial site changes energy of vacancy defect on 0.035 eV, but in opposite direction. Modification of vacancy defects does not change energy of neutral defect level in the band gap in silicon and germanium.

High-resistance samples p-Si (p0 = (1.63 - 7.09)·1011 cm-3) and n-Si (n0 = 1.19·1014 cm-3), grown by the float-ing zone melting after irradiation with fast neutron reactor at 320 C after isothermal and isochronal annealing were studied. The energy levels of divacancy in three charge states, depending on its configuration are deter-mined. Values of the energy levels of divacancies and A - center after their modification background impurities are considered.

The area of temperatures of diffuse and drift movement electrons in n-Si, grown up by Czochralski method after irradiation by the reactor fast neutrons is considered. Temperature dependencies of carrier concentrations in the conducting matrix and in volume of samples are described and the drift barriers determining their specific resistance are calculated. Within the limits of the specified model of the effective environment temperature dependence of specific resistance n-Si (ρ0 = 40 Ω · cm) after irradiation is described by reactor fast neutrons. It is shown that the account of drift barriers and defects recharges in the space-charge areas of defect clusters describes temperature dependence of specific resistance more precisely. It is confirmed that scattering of carriers on the charged defects and clusters taking into account the drift barriers defines the temperature dependence of mobility electrons in n-Si with introduced defects clusters. C. Herring amendment for mobility of electrons is specified at their diffuse movement in n-type silicon irradiated by reactor fast neutrons. Average concentration of carriers in the sample determined from Hall effect measurements is given.

In given article various methods of the increase of the radiation hardness of semiconductors materials such as silicon and InSb are discussed. Parameters of silicon irradiated by different types and fluences of high energy irradiation and annealed were studied by optical and electrical methods. It was shown that the increase of the silicon radiation hardness can be obtained first of all due to radiation-thermal treatments (preliminary radiation and annealing). The important results of the radiation hardness increase were received for neutron irradiated silicon, doped by germanium izovalent impurity.

Thermal stability of clusters and point defects in n-Si grown by Czochralski technique (Cz) was studied after irradiation by thefluence ~ (2 ÷ 4) ⋅ 1013 no ⋅сm-2 of fast-pile neutrons. The effective concentration of carriers after series of isochronal and isothermal annealings of irradiated n-type silicon with n0 = (0.4 ÷ 1.2) ⋅ 1014 сm-3 before irradiation was described in the framework of the defect cluster corrected model. Stages of isochronal annealing process of defect clusters were determined with activation energies (Ea) and frequency factors (ν): Еа1 = 0.81 eV, ν1 = 5.4 ⋅ 106 s-1; Еа2 = 0.4 eV, ν2 = 1 s-1; Еа3 = 1.3 eV, ν3 = 6 ⋅ 104 s-1. Isothermal annealing at 353 K of defect clusters and interstitial atoms ISi (Ec – 0,315 еV) in the conducting matrix of silicon was described with Еа = 0.74 еV and ν = (1 ÷ 3.5) ⋅ 106 с -1.

The dependence of concentration of defects on doping level for average cluster in n-Si was calculated. It was shown that in the framework of the Gossick's model the concentration of defects for the average cluster is in inverse proportion to the square of a cluster radius. One obtains the size distribution of defect clusters created by fast neutrons of WWR-M reactor, by the transformation of energy spectrum of the primary knock-on atom in n-Si (FZ, Cz). Threshold energy of defect clusters formation 4.7 keV by comparing n-Si crystals irradiated by deuterons and fast-pile neutrons was calculated.

It has been studied the high-resistance samples of p-Si (р00 = (3,3 ± 0,5) · 1012 cm-3) and n-Si (n0 = (2,0 ± 0,3) · 1012 cm-3), grown by the floating-zone technique, after irradiation by the fast-pile neutrons at 287 К. The dose and temperature dependences of the effective concentration of carriers have been measured. Calculation has been carried out in the framework of Gossick's corrected model. It was shown that the radiation hardness of n- and p-Si is defined, on one hand, by clusters, on the other hand – by the vacancy defects (acceptors) in n-Si and by interstitial defects (donors and acceptors) in p-Si. It was determined that during the irradiation process of p-Si by small doses of neutrons the change of charge state of interstitial defects leads to the annealing of these defects and to decrease of their introduction rate.

The effect of the ultrasonic (US) processing in regime (fUS = 8 МГц, WUS = 2 Вт/см2 , t ≈ 104 с) on the transformation of radiation defects (RDs) in γ-irradiated (D = 108 and 109 rad) in Chochralski-grown n-type silicon single crystals (9,5 · 1017 см-3) has been studied. The changes of the temperature dependence (100–300 К) of concentration n(T) and mobility µ(T) of charge carriers after γ-irradiated (irreversible changes) and US processing (reverse) has been exposed. Energy positions of the defect levels Eа i and their concentrations Na i from the theoretical computations were determined. Possibility of aсoustostimulated transformation of definite RDs (divacancies V2 - , Ea 1 = (Ес - 0.424 еВ), modified Аcenter (V - O), Ea 2 = (Ес - 0.205 еВ) and complex that can contain nitrogen (? + N), Ea 3 = (Ес - 0,19 еВ)) by means of change of configuration, structure and recharge for example two-dimensional energy configuration-coordinate model is considered.

Radiation hardness of Czochralski grown n-type silicon samples, doped by germanium (NGe = 2 ⋅ 1020 cm-3) and without that was investigated after irradiaton by fast neutrons of WWR-M reactor at room temperature.The dependence of effective carrier concentration on fluence was described in the framework of the improved Gossick’s model. It was found that the introduction of germanium leaded to the increase of n-Si radiation hardness by factor of seven times. The isothermal annealing of n-Si after fluence 1,4 ⋅ 1014 no ⋅cm-2 was studied for three temperatures. It was shown that the annealing of defect clusters is caused by the annihilation of vacancy type defects in clusters with the interstitial defects. Migration energy and frequency factor for di-interstitial (Е1 = 0,74 eV; ν1 = 3,5 ⋅ 106 s-1), for silicon interstitial atom (Е2 = 0,91 eV; ν2 = 7 ⋅ 107 s-1) and for vacancy (Еv = 0,8 eV; ν = 1 ⋅ 107 s-1) were determined.