Vplyv olova na strukturni peretvorennya tonkoplivkovoyi suboksydnoyi matrytsi kremniyu

Abstract

The processes of crystallization of amorphous silicon (a-Si) in the a-SiOxSn (1 ≤ x ≤ 2) sub-oxide matrix have been studied. The temperature, at which the crystallization begins, is shown to be lower for a-SiOxSn films with higher tin contents. For specimens with the maximum tin content (about 2 vol.%), the crystallization begins at a temperature of 500 ∘C; for specimens with the average tin content (about 1 vol.%), the crystallization temperature equals 800 ∘C; and for specimens with the minimum tin content (about 0.5 vol.%), the crystallization of a-Si starts at 1000 ∘C. On the other hand, it is shown that tin does not influence the separation of a-Si and the SiO2 phase in the examined specimens. It is found theoretically that silicon crystallites that are formed during the crystallization of a-Si are much smaller (d ≈ 5÷7 nm) in a-SiOxSn films with a high tin content (1 and 2 vol.%) in comparison with the tin-free specimens (d ≥ 10 nm). A metal-induced mechanism of crystallization of a-Si has been proposed, which predicts the existence of tin metal clusters in SiOx that create conditions for the easier transition of the amorphous silicon phase into the crystalline one. On the basis of experimental data, it is supposed that, in our case, a necessary condition for the crystallization of a-Si by the proposed metal-induced mechanism to start is the presence of metal (tin) aggregates in SiOx.