Yu. N. Buzynin

Fianite: A multipurpose electronics material

Fianite-zirconium dioxide, stabilized by yttrium (YSZ) has a unique combination of physical and chemical properties that made it a very promising material for a wide range of applications. In this work, we consider the use of fianite as a bulk substrate and buffer layer for AIIIBV epitaxy, and as an antireflection and protective coating for photo detectors and solar cells.

Single-crystalline GaAs, AlGaAs, and InGaAs layers grown by metalorganic VPE on porous GaAs substrates

Conditions for the growth of single-crystalline GaAs, AlGaAs, and InGaAs layers by metalorganic VPE were established and the corresponding semiconductor films were obtained on porous GaAs substrates. Comparative data on the morphology, structure, and electrical homogeneity of the epitaxial layers grown on the porous and monolithic substrates are presented. It was found that passage to the porous substrates leads to changes in the film growth rate and morphology, the concentration of electrically active defects, and their distribution in depth of the epitaxial structures.

Heteroepitaxial III–V films on fianite substrates and buffer layers

GaAs, GaSb, AlGaAs, and InGaAs epitaxial films and multilayer AlGaAs/InGaAs/GaAs heterostructures for PHEMT field-effect transistors have been obtained on fianite substrates by metal-organic vapour phase epitaxy. Films of different III–V compounds, including GaN, were grown on Si and GaAs substrates with a simple single buffer layer (fianite) and double buffer layer (fianite on porous Si and GaAs). It is established that the use of a two-layer buffer improves the structural quality and homogeneity of III–V films. A possibility of controlling the phase composition of GaN films using a corresponding buffer layer is shown. It is found that the use of a two-layer buffer increases the electrical homogeneity and decreases the electrical activity of defects in GaN films.

Growing InN films by plasma-assisted metalorganic vapor-phase epitaxy on Al2O3 and YSZ substrates in plasma generated by gyrotron radiation under electron cyclotron resonance conditions

Hexagonal indium nitride (InN) films on (111)- and (100)-oriented yttria-stabilized zirconia (YSZ) substrates and (0001)-oriented Al2O3 substrates have been grown for the first time at a rate of 1 μm/h by the method of metalorganic vapor-phase epitaxy with plasma-assisted nitrogen activation in an electron cyclotron resonance discharge generated by gyrotron radiation at low-temperature (350°C) growth. InN films grown without buffer layers possess a textured polycrystalline structure. Using an InN/GaN double buffer layer, single-crystalline InN films have been obtained on Al2O3(0001) substrates. Data on the morphology, structure, and photoluminescent properties of the obtained InN films are presented.

High-rate growth of InN films on fianite and sapphire substrates by metalorganic vapor phase epitaxy with plasma-assisted nitrogen activation

Hexagonal single-crystalline indium nitride (InN) films on (0001)-oriented sapphire (Al2O3) and (111)-oriented fianite (yttria-stabilized zirconia, YSZ) substrates and on (0001)-oriented GaN/Al2O3 templates have been grown at a record high rate of 10 μm/h by the method of metalorganic vapor phase epitaxy with nitrogen activation in plasma of electron cyclotron resonance discharge generated by gyrotron radiation. It is established that the use of fianite substrates significantly improves the structural perfection and photoluminescent properties of InN films as compared to those grown on sapphire and templates. Undoped InN films exhibit n-type conductivity with electron concentrations within n = 8.0 × 1019–4.9 × 1020 cm−3 and room-temperature mobilities up to 180 cm2/(V s).

Epitaxial films of GeSi, AlGaN, and GaSb and GaSb/InAs superlattices on substrates of fianite

Fianite is a single crystal of cubic solid solutions based on zirconium dioxide (ZrO2) or hafnium dioxide (HfO2) with stabilizing oxides of yttrium, scandium, and lanthanides. It is characterized by a unique combination of physical and chemical properties, making it a promising material for wide use in electronics. In this work, we consider new uses of fianite as a monolith substrate for obtaining Ge, GeSi, AlGaN, and GaSb epitaxial films and GaSb/InAs superlattices.

Antireflection fianite and ZrO2 coatings for solar cells

Fianite is a promising multipurpose material for new electronic technologies owing to its unique combination of physical and chemical properties. It can be used in virtually all of the main technological stages of the production of micro-, opto-, and SHF-electronics; in particular, as a bulk dielectric substrate and a material for buffer layers in heteroepitaxy; as a material for insulating, antireflection, and protective layers in device elements; and as a gate dielectric [1–3]. In this work, we consider the possibilities for using fianite and ZrO2 as an antireflection coating for silicon solar cells (SCs) and SCs based on InGaAsP heterostructures.

Heteroepitaxial GaN films on silicon substrates with porous buffer layers

New complex buffer layers based on a porous material have been developed for epitaxial growth of GaN films on Si substrates. The characteristics of gallium nitride heteroepitaxial layers grown on silicon substrates with new buffer layers by metal-organic vapor phase epitaxy are investigated. It is shown that the porous buffer layers improve the electric homogeneity and increase the photoluminescence intensity of epitaxial GaN films on Si substrates to the values comparable with those for reference GaN films on Al2O3 substrates. It is found that a fianite layer in a complex buffer is a barrier for silicon diffusion from the substrate into a GaN film.

Structure and properties of porous GaAs

In this paper we report the first results obtained in the study on the properties of porous GaAs (P-GaAs) produced by electrochemical etching in electrolytes on the basis of hydrofluoric acid. As the initial material we used monocrystalline n- and p-type (100)GaAs substrates Te- and Zn-doped to 2*1018 cm-3 and 6*1018 cm-3, respectively. The substrates were subjected to chemical-mechanical and diamond-paste polish. Etching was performed in an electrolytic cell with a platinum cathode in the galvanostatic regime with anode current densities ranging from 5 to 150 mA/cm2. We were interested in P-GaAs layers with thicknesses from 0.5 to 50 micrometers. The methods used in the study of P-GaAs samples included x-ray diffractometry, electron microscopy, x-ray microanalysis, secondary ion-mass spectroscopy, electrochemical C-V profiling and photoluminescence.

Thin single-crystal Ge layers on 2″ Si substrates

Conditions for preparing thin homogeneous mirror-smooth Ge layers on 2″ Si substrates by hot wire chemical vapor-phase deposition have been determined. Ge layers 200 nm thick have a structure of epitaxial mosaic single crystal with almost completely relaxed elastic stresses. The X-ray diffraction rocking curve half-width is less than 6′. The density of grown-in dislocations in Ge layers is in the range of (3–6) × 105 cm−2, and the rms surface roughness does not exceed 0.8 nm.