RF PLASMA EFFECT ON AMORPHOUS THIN ION-IMPLANTED LAYERS OF N- AND P-TYPE GERMANIUM: RAMAN AND AFM RESEARCH

Effect of RF plasma treatment (RFPT) and rapid thermal annealing (RTA) on high-dose implanted n-type and p-type amorphous Ge layers has been studied by Raman scattering spectroscopy and AFM techniques. To recrystallize the amorph-ous thin n-Ge layer implanted by BF2+ ions needed higher RTA temperatures and power density of RFPA than in the case of p-Ge implanted by P+ ions with a same dose. It was shown that the RFPT resulted in recrystallization of amorphous Ge layers at considerably lower temperatures than RTA, that it was associated with nonthermal effects. Low-energy ion and electron bom-bardment during RFPT resulted in formation of nanostructured Ge surface

Azimuthal and polar anchoring energies of aligning layers structured by nonlinear laser lithography

In spite of the fact that there are different techniques in the creation of the high-quality liquid crystals (LCs) alignment by means of various surfaces, the azimuthal and polar anchoring energies as well as the pre-tilt angle are important parameters to all of them. Here, the modified by a certain manner aligning layers, previously formed by nonlinear laser lithography (NLL), having high-quality nano-periodic grooves on Ti surfaces, recently proposed for LC alignment was studied. The change of the scanning speed of NLL in the process of nano-structured Ti surfaces and their further modification by means of ITO-coating, and deposition of polyimide film has enabled different aligning layers, whose main characteristics, namely azimuthal and polar anchoring energies, were measured. For the modified aligning layers, the dependencies of the twist and pre-tilt angles for LC cells filled by nematic E7 ({\Delta}{\epsilon} > 0) and MLC-6609 ({\Delta}{\epsilon} < 0) were obtained. Also the contact angle for droplets of isotropic liquid (glycerol), and nematic LCs was measured for the various values of the scanning speed during the laser processing.Comment: 49 pages, 18 figure

Direct magnetic and surface relief patterning using carbazole-based azopolymer

The results on using of carbazole-based azopolymer layers (Polyepoxypropylcarbazole:Methyl Red with magnetic particles of Fe2SO4) for the recording of 1-D and 2-D surface relief gratings are presented in this report. Morphology study using AFM and MFM of obtained structures has shown their good quality. Surface relief gratings with profile height up to 1.2 µm were obtained during the holographic recording using blue laser. Along with surface relief grating it was shown the direct formation of magnetic relief. Possibility of simultaneous direct fabrication of surface and magnetic relief by optical holographic recording using azopolymer thin films as recording media was shown

ХІМІЧНЕ РОЗЧИНЕННЯ InAs, InSb, GaAs ТА GaSb В ТРАВИЛЬНИХ КОМПОЗИЦІЯХ (NH4)2Cr2O7−HBr−H2O

The features of InAs, InSb, GaAs, and GaSb dissolution in the (NH4)2Cr2O7−HBr−H2O etching compositions have been investigated. The chemical-dynamic polishing in the reproducible hydrodynamic conditions has been used. It was established that the arsenides etching rate changed similarly and achieved the maximum values in the oxidant saturated mixture (22 vol.%). It was found that the antimonides dissolution rate increases when the (NH4)2Cr2O7 concentration is increasing also. It was established that all etching compositions are polishing for InAs and GaAs, and in the case of InSb and GaSb the polishing solutions occupy about 50 % of the investigated concentrated regions. It was shown that the dissolution rate of all crystals decreases to 0,1 μm/min and the quality of the antimonides surface degrades when the H2O concentration is increasing. The substrates dissolution has the diffusion nature. Using metallographic analysis and atomic force microscopy it was confirmed a good quality of InAs, InSb, GaAs and GaSb surface obtained after chemical treatment in the (NH4)2Cr2O7−HBr−H2O polishing solutions.Проведено дослідження особливостей взаємодії InAs, InSb, GaAs та GaSb з травильними розчинами (NH4)2Cr2O7−HBr−H2O. Визначено вплив складу травника, його швидкості перемішування та температури на швидкість розчинення підкладок. Установлений дифузійний механізм процесу розчинення кристалів (Еа=8,1-9,7кДж/моль). Показано, що хіміко-динамічне полірування травниками складу (NH4)2Cr2O7−HBr−H2O зменшує структурні порушення напівпровідників (Ra=0,2-9,3 нм)

CHEMICAL DISSOLUTION InAs, InSb, GaAs AND GaSb IN THE (NH4)2Cr2O7−HBr−H2O ETCHING COMPOSITIONS

The features of InAs, InSb, GaAs, and GaSb dissolution in the (NH4)2Cr2O7−HBr−H2O etching compositions have been investigated. The chemical-dynamic polishing in the reproducible hydrodynamic conditions has been used. It was established that the arsenides etching rate changed similarly and achieved the maximum values in the oxidant saturated mixture (22 vol.%). It was found that the antimonides dissolution rate increases when the (NH4)2Cr2O7 concentration is increasing also. It was established that all etching compositions are polishing for InAs and GaAs, and in the case of InSb and GaSb the polishing solutions occupy about 50 % of the investigated concentrated regions. It was shown that the dissolution rate of all crystals decreases to 0,1 μm/min and the quality of the antimonides surface degrades when the H2O concentration is increasing. The substrates dissolution has the diffusion nature. Using metallographic analysis and atomic force microscopy it was confirmed a good quality of InAs, InSb, GaAs and GaSb surface obtained after chemical treatment in the (NH4)2Cr2O7−HBr−H2O polishing solutions