Doping mechanisms of gallium arsenide with tin in gas phase epitaxy processes

A thermodynamic calculation of the equilibrium composition of the gas phase Ga-As-Sn-Cl-H system was carried out. An estimate of the impurity composition of adsorbate layers was made. A study of the electrophysical and photoluminescent properties of tin-doped GaAs epitaxial layers was conducted. From a comparison of the calculated and experimental data, it follows that the dependence of trapping mechanisms for tin on the conditions of epitaxial growth corresponds to changes in the gas phase and adsorbate layer compositions. A mechanism is proposed in which the introduction of impurities into the layers in elemental and complex forms occurs due to capture of atomic and diatomic tin adsorbed on the surface.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 37–40, June, 1990.     

Preparation and properties of epitaxial ZnGeP2 films

Thermodynamic analysis has been applied to the vapor over a ZnGeP₂ crystal when the chlorine source is provided by ZnCl₂. ZnGeP₂ film growth has been examined and the electrophysical and photoluminescence parameters have been measured. All these autoepitaxial films have the chalcopyrite structure, while those parameters are determined by the defects and the substrate orientation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 74–78, April, 1988.We are indebted to L. G. Lavrent'eva for interest, to A. I. Gribenyukov and T. E. Tkachenko for assistance in growing the single crystal; and to F. Kim for the microprobe analysis.     

Defects in the GaAs and InGaAs layers grown by low-temperature molecular-beam epitaxy

The problem of defect formation in the GaAs and InGaAs layers grown by low-temperature molecular-beam epitaxy is discussed. The effect of growth conditions (temperature and flux ratio between the elements of groups III and V) on the morphology of growth surface, internal structure, type, and concentration of electrically-and optically active defects is analyzed. A comparison is made between the defect formation processes occuring during the epitaxial growth and post-growth annealing of the layers. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 63–72, December, 2006.     

Influence of thermal processing on the properties of Sn-doped GaAs epitaxial layers

The influence of annealing at a temperature of 750–830°C on the electrophysical, luminescent, and structural characteristics of GaAs layers doped with various concentrations of tin is studied. It is shown that, for low doping levels, the layers possess properties with high thermal stability. During annealing, one observes a lowering of the concentration of electrons, a reduction of the lattice periodicity, and a change in the photoluminescence spectra of strongly-doped layers, which is explained by the process of the formation of complexes and by the decomposition of supersaturated solid solutions of impurity dopants.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 54–59, January, 1989.The authors express gratitude to M. P. Yakuben for x-ray topographical studies.     

Complexing of tellurium-doped gallium arsenide in gas-phase epitaxy

The effect of the conditions of gas-phase epitaxy on complexing in tellurium-doped layers of gallium arsenide is studied. Measurements of the intensities of the corresponding photoluminescence lines were used to estimate the concentration of optically-active complexes. A correlation was found between the processes involved in complexing, the growth velocity, and impurity trapping in the layers. The determining role of the surface structure in the formation of complexes, including impurity atoms, is demonstrated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 96–100, February, 1985.     

Structure and properties of epitaxial layers of InxGa1−xAs grown from the gas phase

A study has been made of the dependence of the crystal lattice parameter and the structural perfection of epitaxial layers of In_xGa_1–xAs on substrates of GaAs and InP and on the composition of the solid solution. The electrophysical properties of layers of various compositions have been studied. From measurements of the photoluminescence spectra, a determination has been made of the dependence of the width of the forbidden band on the composition of the layers.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 46–50, February, 1992.     

Study of the Elementary Growth Processes During Vapor-Phase Epitaxy of Semiconducting III–V Compounds

A review of studies performed at the V. D. Kuznetsov Siberian Physical-Technical Institute at Tomsk State University and aimed at obtaining detailed information on the elementary growth processes proceeding at the crystallization front during vapor-phase epitaxy of semiconducting III–V compound films is presented in the paper. The general approach to the problem and methods of its solution are described. Results of investigations of the adsorption layer composition, surface diffusion processes, and incorporation of growth components into a crystal are presented. The mechanism of epitaxial layer growth in semiconducting III–V compounds is discussed.     

Synthesis and Crystal Structure of Dinitratotetra(hexamethylphosphoric Triamide)-Lanthanum(III)Tetra(Isothiocyanato)Diammine Chromate(III)

A new coordination compound having the formula [La(HMPA)₄(NO₃)₂][Cr(NH₃)₂(NCS)₄] (I), where HMPA is ((CH₃)₂N)₃PO, has been synthesized and studied by X-ray diffraction. Studied crystals of compound I are monoclinic, space group P2₁/n, a = 15.0360(3) Å, b = 15.1214(3) Å, c = 26.7529(7) Å, β = 100.6610(10)°, V = 5977.7(9) Å3, Z = 2, ρ_calc = 1.442 g/cm³, and R₁ = 0.0453 for 7344 reflections with F_o ≥ 4σ(F_o).     

Physics of semiconductors and dielectrics theoretical and experimental study of surface Processes during vapor-phase epitaxy of III–V compounds

Elementary surface processes occurring during vapor-phase epitaxy of the III–V compounds are studied using experimental and calculation methods. The calculated vapor-phase composition in the reactor and the adsorptionlayer composition on the growth surface were compared with the experimental data on the surface structure and electrophysical properties of GaAs layers doped with Zn and Te. This allowed the characteristic quantities of surface processes such as average diffusion length and surface diffusion coefficient for host-material (for GaAs, InAs, and InP) and impurity (Zn, Te) atoms to be estimated. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 3–7, May, 2006.     

Evolution of Surface Morphology of Anthracene Single Crystals Under Annealing

Russian Physics Journal - In this work, the effect of formation of macrosteps under dissolution of the anthracene single crystal surface is shown for the first time. Under standard conditions (room...