Papers by Keyword: Liquid Phase Epitaxy (LPE)

Abstract: Abstract. Excitation and emission spectra under UV and X-ray excitations, as well as the luminescence decay kinetics of Gd₃Ga₅O₁₂: Bi single crystalline films were studied. The emission spectra observed in the spectral region 350-700 nm at room temperature consist two elementary bands peaked at 446 and 521 nm. The influence of growth conditions on the luminescent properties of Gd₃Ga₅O₁₂: Bi³⁺ garnet have been revealed. The integral and relative intensities of the luminescence bands depend on the excitation wavelength. The Bi³⁺ decay curves of all investigated films show non-single exponential behavior at room temperature.

Abstract: The series of (LuBi)3Fe5O12 film were grown on (111) oriented GGG substrate with diameters 1, 2 and 3 inch by liquid phase epitaxy using Bi2O3-base flux. Different types of surface morphology on the grown films were observed. The films’ surface was smooth and mirror while the film thickness was less than 13 μm and becomes rough for thickness above this value. The grown films were characterized by measuring magnetization loops and magneto-optic Faraday rotation under magnetization reversal as well as ferromagnetic resonance (FMR). All films with mirror surface demonstrate the in-plane magnetization, high Faraday rotation and FMR linewidth about 0.8 Oe at 9.1 GHz and room temperature.

Abstract: The La-doped yttrium iron garnet (YIG) films with thickness up to 130 μm were grown by liquid phase epitaxy (LPE) method. All grown thick films demonstrate “mirror” and “striation” types of surface morphology that depend from film growth temperature and thickness. Addition of B2O3 is favourable to a change the surface morphology into a “mirror” one. The mechanisms of the morphological changes are discussed. It was found that the ferromagnetic resonance (FMR) linewidth appreciably depends from surface morphology of grown films. For thick films with “mirror” surface the FMR linewidth is less than 0.8 Oe and more than ten times less in comparison with films with “striation” surface.

Abstract: We have investigated the Si-seeding rapid-melting process and demonstrated the formation of giant Ge stripes with (100), (110), and (111) orientations on Si (100), (110), and (111) substrates, respectively, covered with SiO₂ films. We revealed that crystallization is triggered by Si-Ge mixing in the seeding regions in this process. Based on this mechanism, we have proposed a novel technique to realize orientation-controlled Ge layers on transparent insulating substrates by using Si artificial micro-seeds with (100) and (111)-orientations. This achieved epitaxial growth of single crystalline (100) and (111)-oriented Ge stripes on quartz substrates. The Ge layers showed a high hole mobility exceeding 1100 cm²/Vs owing to the high crystallinity.

Abstract: In the present work the defects appearing in layers grown by liquid phase epitaxy on different substrates are compared. The used seeds were (i) 3C-SiC with (111) orientation, grown heteroepitaxially on (0001) 4H-SiC or 6H-SiC substrates by continuous feed physical vapour transport process and the vapour-liquid-solid mechanism, respectively, and (ii) 3C-SiC wafer with (100) orientation from HOYA. The structural and optical investigation showed that (i) on the (111) substrates, due to the appearance of silicon and 6H-SiC inclusions, a layer which consisted of a sequence of long period polytypes was formed. The dominant polytype formed was 21R-SiC, which after successive transformation to 39R- and 57R- SiC led to the formation of 6H-SiC on the top of the layer. (ii) On the (100) substrates, a 3C-SiC layer with comparatively uniform defect density was formed. The main defects were stacking faults and their density was reducing during the process.

Abstract: 6H-SiC hetero-epitaxially grown on a (111) 3C-SiC was observed with TEM. High-density stacking faults were formed around the hetero-interface, and the density of stacking faults decreased with increasing distance from interface. On the other hand, when 3C-SiC was homo-epitaxially grown on a 3C-SiC, any stacking faults did not exist at the interface between the grown crystal and the seed crystal. Thus, the stacking faults formation started from the 6H/3C hetero-interface. Considering the lattice-mismatch strain between 3C-SiC and 6H-SiC, the strain energy is equivalent to the stacking fault energy of 6H-SiC. This similarity suggests that the stacking faults formation could be caused by the relaxation of the lattice-mismatch strain.

Abstract: The influence of nitrogen impurity on the stabilization of 3C-SiC polytype has been studied during vapour-liquid-solid (VLS) growth on 6H-SiC(0001) seed with Si-Ge melt. By changing the partial pressure of N2 during growth, it was found that the proportion of 3C-SiC inside the grown material increases with N2 partial pressure. 6H inclusions are only found for high purity (low N2 content) conditions. The possible interactions proposed to explain this effect are divided in two effects: i) lattice parameter modification and ii) surface induced lateral enlargement variation. A combination of both effects is suspected.

Abstract: Despite outstanding properties, the development of 3C-SiC electronics is still suffering from the lack of bulk 3C-SiC substrates. Up to now, there is no real seed and optimized growth processes for this material. We address in this work the bulk growth of 3C-SiC by a two-step-liquid phase approach. By coupling experiments with global process simulation, we address the problems that must be overcome to consider the solution growth technique as a possible approach for the growth of bulk 3C-SiC.

Abstract: We report in this work, the solution growth of heavily p-type doped 3C-SiC and 6H-SiC. Description of the 3C and 6H-SiC crystals in terms of defects and resistivity are presented and discussed with respect to growth conditions such as temperature, Al content in the melt and seed polarity. Crystals and thick layers are investigated by means of TEM, NDIC microscopy and Raman.

Abstract: We attempted the vapor–liquid–solid (VLS) growth of SiC film in Si-Li solution using gaseous CH4 as a carbon source at 900 oC. A 100-m-thick liquid-phase epitaxy (LPE) layer was obtained on a 4H-SiC (0001) substrate under CH4 pressure of 0.9 MPa. X-ray diffraction (XRD) and a high-resolution transmission electron microscope (HR-TEM) measurement showed that the LPE layer was single-phase 2H-SiC. We concluded that VLS growth in Si-Li solution using gaseous CH4 as a carbon source is useful for growing single-phase 2H-SiC.