No abstract

By the methods of transmission electron microscopy, high energy electron diffraction, atomic force microscopy, and Auger electron spectroscopy, the article studies the phase composition, orientation, substructure, and morphology of the films formed during pulsed photon treatment (PPT) by radiation of xenon lamps of silicon (111) Si substrates in an atmosphere of methane. We have established that in the range of the energy density of radiation (Ep) supplied to the substrate with a thickness of 0.45 μm for 3 s from 269 to 284 J cm-2 the oriented nanocrystalline films are formed on both surfaces of the substrates both from the irradiated and non-irradiated side β-SiC thickness of about 150 nm. In this case, the synthesis of films on the irradiated side is carried out with the possible participation of photon activation of processes and on the reverse side – only by thermal activation (short-term heat treatment (SHT). With an increase in the energy density of radiation in β-SiC films, the average subgrain size on the irradiated side is shown to increase from 4.2 nm (Ep = 269 J ·cm-2) to 7.9 nm (Ep = 284 J ·cm-2) and on the non-irradiated side 3.9 to 7.0 nm respectively. The surface roughness of the β-SiC surface proceeds consequentially on the irradiated side from 19 nm (Ep = 269 J ·cm-2) to 60 nm (Ep = 284 J ·cm-2) and on the non-irradiated side from 11 nm to 56 nm respectively. Based on the temperature dependences of the average grain size and roughness, we have estimated the apparent activation energies of the processes. The activation energy of subgrain β-SiC growth is practically independent of the activation method and is 1.3 eV. The activation energy for the evolution of roughness is 2.5 eV at a PPT and 3.5 eV at a SHT.

Polycrystalline LiNbO 3 films on (001)Si substrate were grown by radio-frequency magnetron sputtering process at different sputtering conditions. X-ray diffraction analysis showed that films formed in Ar environment (P = 5.0 × 10 −1 Pa) having two-phase composition (LiNbO 3 , LiNb 3 O 8 ) transformed into c-axes-oriented LiNbO 3 films when Ar pressure declined up to P = 1.5 × 10 −1 Pa. This induced an increase in positive oxide charge and coercive field due to formation of defects in the LiNbO 3 layer. Using Ar + O 2 reactive gas mixture led to decline in defect formation (positive oxide charge) and coercive field. Current-voltage and capacitance-voltage analyses demonstrated that barrier properties of the Si-LiNbO 3 heterojunctions are affected by the plasma composition.