[en] Status of experimental investigations into defect formation in semiconductor related to relaxation of electron excitations is reviewed. The results from impurity-ionization mechanism studies on germanium and indium antimonide are considered in details, as in this case a qualitative comparison of experimental results with those of consistent analytical theory may be carried out. Conditions under which efficiency of this mechanism may be compared to that of elastic displacement mechanism even at above threshold irradiation are determined. Experiments where recombination-heat mechanism of defect transformation is observed are discussed. Information on diffusion-drift annealing of Frenkel pairs that in due conditions may control defect formation, resulting in pair annihilation directly after their production, is presented

[en] The types of point defect which appear in germanium under electron or γ-irradiation depend on the impurity content and irradiation conditions. It seems that, in lightly doped n-type material at 4.2 K irradiation, metastable close Frenkel pairs can be created, energy barriers for the I-V separation or annihilation being dependent on their charge state. At energies of bombarding electrons high enough for secondary displacement, one can observe (under 4.2 K and 77 K irradiation) the defects which have been tentatively identified as divacancies anchored to self-interstitials (the analogue of the nonreorientable divacancy in silicon). The fact of the participation of the impurity atoms in defect production at 300 K, 77 K and even 4.2 K irradiation can now be taken for granted. The primary defects can interact with elements of groups III and V, such as oxygen, lithium, copper and possibly silicon. Subthreshold defects were observed in germanium with hydrogen, the cross section of their formation being five orders smaller than the superthreshold cross section; thus some changes in hydrogen atom space configuration may lead to the threshold defect formation. The main unanswered question at the moment concerns the detailed mechanism of the primary defect-impurity interaction. (author)

[en] The review of results of the study of defects arising in semiconductors after heating with subsequent quenching is given. Considerable attention is given to the problem on the nature and mechanisms of ''thermodonors'' formation in silicon, complexes comprising the 5-th group atoms in germanium. In binary compounds the most important reason of thermal defects formation is stoichiometry deviation. The self-compensation phenomenon in semiconductors is discussed

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[en] The effect of ⁶⁰Co gamma-radiation at 4.2 K on the electric parameters of the n-type germanium is investigated. It is shown that donors of the 5th group under these conditions do not take part in the defect formation. The formation of singly charged acceptor centers of two types is observed. The main contribution into the change of electric parameters makes acceptor centers, annealed in the 30-50 K temperature range, annealing being, probably, conditioned by their ionization in that temperature range. These defects more likely represent Frenkel metastable pairs. Some differences in the n-type germanium behaviour under ⁶⁰Co gamma-irradiation and under 1-2 MeV electron irradiation are probably connected with the fact that in these two cases the distribution of the forming Frenkel pairs over the distance between the pair components is different

[en] A diagram of energy states of intrinsic interstitial I and vacancy V in germanium allowing to explain a lot of various experimental data relating to the processes of low-temperature annealing of the Frenkel pairs under different conditions is suggested. The analysis carried out shows that isolated I and V can be in charge states I⁰, I⁺, V^- and V⁰. To these charge states can be added I²⁺ and V²⁺ in the composition of ''similar'' Frenkel pairs

[en] The paper discusses the role of electronic excitations in atomic processes in semiconductors. Two types of ionization-enhanced processes are considered: (1) generation of primary defects; (2) defect reactions, including defect migration. A recently proposed efficient mechanism of ionization-enhanced defect generation associated with impurity action and some related experimental data are discussed. Main types of models for ionization-enhanced defect reactions and relevant experimental results are considered. An attempt is made to present the contemporary general picture of ionization-enhanced processes in semiconductors. (author)

[en] The process of copper atom ''activation'' in crystals of pure especially pure germanium with the charge carrier concentration of 10¹²-10¹³ and < or approximately 10¹¹ cm^-3, accordingly grown in vacuum under ⁶⁰Co gamma irradiation (copper atom transition from electrically inactive state to electrically active in the substitution position) is discusssed. It is shown that the concentration of dissolved copper in germanium even during the most careful purification from impurities amounts to (2-4)x10¹² cm^-3. It is concluded that in nonirradiated crystals of pure and especially pure germanium the copper atom impurity are mainly not in points of a crystal lattice but are captured apparently with dislocations. During the gamma irradiation they are liberated from impurity atmospheres of dislocations and are turned to the crystal volume occupying the vacant points. The above process cross section amounts to 2x10^-27-1x10^-26 cm², according to evaluations depending on the Fermi level position. The complete activation of the copper impurity occurs at the dose PHI < or approximately 10¹⁶ cm^-2. It is shown that in germanium crystals grown in hydrogen atmosphere at the same degree of purification from impurities copper levels are not detected in a marked concentration either in the source material or in the material after gamma irradiation