NUgzar Dolidze

 It is shown, that in gallium arsenide by irradiation with high integral streams (F ³ 1016 cm-2) of the accelerated electrons (E=3Ìev) at T=300K, radiation defects in single-charge states are created. The fluctuative electric field strength and corresponding concentration of radiation defects which "destroy" exciton are estimated. The broadening parameter of exciton peak as a concentration function of radiation defects is determined.

We have studied the effect of neutron irradiation on the exciton absorption in n-GaAs crystals. It is shown that the observed decrease in the absorption coefficient, broadening of the exciton peak, and its shift toward higher energies are caused by the electric and strain (compression) fields generated by the radiation-induced defects.

We have studied the effect of neutron irradiation on the microhardness of n-GaAs crystals. It is shown that the growth and saturation of microhardness with increasing radiation dose Φ, as previously reported in the literature, take place only in the dose range Φ∼1015−5×1016 cm−2. As the neutron dose is increased further, the microhardness continues to grow due to the increasing role of the radiation-induced disordered regions in n-GaAs.

The low-temperature laser annealing of the radiation defects created in n-GaAs by accelerated electrons has been investigated. It is shown, that the laser action can promote both annealing and recharge of radiation lattice defects. 

he process of low-temperature pulse-photon annealing of defects created in n-Si by implantation Ar+ was investigated. It is shown, that for annealing of postimplantative radiation defects complex use of thermal and pulse-photon treatment is more effective.

Laser annealing of amorphous silicon (a-Si) at different initial temperatures (77 and 300 K) has been studied. It is established that the laser-stimulated crystallization of silicon is possible at relatively low temperatures. A theoretical model is proposed, which explains this phenomenon by melting via the electron mechanism followed by recrystallization.

The nature of internal mechanical stresses in the thin silicon-on-sapphire (SOS) epitaxial films is studied, and their value is estimated. They are ∼1019 Pa and have a compressive character. The effects of pulsed laser and lamp annealings on stress relaxation are analyzed, and stress relaxation is shown to reach 90% under certain annealing conditions. An electron mechanism, which is based on a change in the quantum state of the electron subsystem of a crystal during pulsed photon annealing, is proposed for annealing of structural defects.