Исследованы вольт-амперные характеристики барьеров Шоттки Au/Ti/ n-InAlAs/InP в температурном диапазоне 100-380 K. Показано, что при повышении температуры от 100 до 200 K коэффициент идеальности уменьшается от 1.58 до 1.1, а высота барьера повышается от 0.55 до 0.69 eV. При дальнейшем повышении температуры от 200 до 380 K коэффициент идеальности и высота барьера изменяются слабо. Такое поведение хорошо согласуется с моделью латеральной неоднородности высоты барьера (модель Танга), что подтверждается линейной зависимостью высоты барьера от коэффициента идеальности в диапазоне температур 100-200 K. В соответствии с этой моделью были рассчитаны значения высоты барьера гомогенного перехода 0.88 eV, среднеквадратичного отклонения 10-4cm2/3· V1/3 гауссова распределения высоты барьера, эффективной площади областей с пониженной высотой барьера 3.7· 10-11 cm2 и постоянной Ричардсона 10.7 A· cm-2· K-2. DOI: 10.21883/PJTF.2017.12.44712.16700

Current–voltage (I–V) characteristics of Au/Ti/n-InAlAs/InP Shottky barriers have been studied in a temperature range of 100–380 K. It is established that, as the temperature increases from 100 to 200 K, the ideality factor drops from 1.58 to 1.1, while the barrier height grows from 0.55 to 0.69 eV. With a subsequent temperature increase from 200 to 380 K, both the ideality factor and barrier height vary, but only weakly. This behavior agrees well with the model of lateral inhomogeneity of the barrier height (Tung model), which is confirmed by the linear dependence of the barrier height on the ideality factor at temperatures within 100–200 K. Calculations according to this model yielded the value of 0.88 eV for the homogeneous-junction barrier height, 10–4 cm2/3 V1/3 for the mean-square deviation of the Gaussian distribution of barrier heights, 3.7 × 10–11 cm2 for the effective area of regions with reduced barrier heights, and 10.7 A cm–2 K–2 for the Richardson constant.

The parameters of multilayer CdxHg1–xTe heterostructures for photodetectors operating at wavelengths of up to 5 μm, grown by molecular-beam epitaxy (MBE) on silicon substrates, are studied. The passivating properties of thin CdTe layers on the surface of these structures are analyzed by measuring the C–V characteristics. The temperature dependences of the minority carrier lifetime in the photoabsorption layer after growth and thermal annealing are investigated. Samples of p +–n-type photodiodes are fabricated by the implantation of arsenic ions into n-type layers, doped with In to a concentration of (1–5) × 1015 cm–3. The temperature dependences of the reverse currents are measured at several bias voltages; these currents turn out to be almost two orders of magnitude lower than those for n +–p-type diodes.

The characteristics of SWIR (1.6-3 mu m) 320 x 256 and 1024 x 1024 focal plane arrays (FPA's) based on n-type In-doped HgCdTe heteroepitaxial layers are reported. The HgCdTe layers were grown by molecular beam epitaxy on silicon substrates with ZnTe and CdTe buffer layers. p-n junctions were formed by arsenic ion implantation into HgCdTe film. Reverse current in the temperature range from 210 to 330 K was found to be limited by the diffusion mechanism. At the same time in the temperature range from 140 to 210 K the reverse current was dominated by the thermal generation of charge carriers through deep traps located in the middle of the band gap. At 170 K NETD was less than 40 mK (C) 2016 Elsevier B.V. All rights reserved.

We studied the electrical properties of undoped and indium-doped and arsenic-doped Cd X Hg 1-X Te layers with x ≈ 0.3 - 0.4 grown by molecular beam epitaxy on Si (310) substrates. After the growth HgCdTe layers were annealed at mercury atmosphere. The lifetime at room temperature in the As-doped layers, do not depend on its carrier concentration. The lifetime in indium-doped layers increased after annealing at saturated mercury vapor pressure. It is explained by suppression of recombination centers density. Temperature dependence of the reverse currents of p +- n junctions fabricated in Cd 0.3 Hg 0.7 Te heterostuctures grown by MBE on Si substrates has been studied.

Приведены результаты исследования параметров многослойных гетероструктур CdxHg1-xTe для фотоприемников диапазона длин волн до пяти микрометров, выращенных методом молекулярно-лучевой эпитаксии на кремниевых подложках. Методом C-V-характеристик исследованы пассивирующие свойства тонких слоев CdTe на поверхности таких структур. Исследованы температурные зависимости времени жизни неосновных носителей заряда в фотопоглощающем слое после роста и после отжигов. Фотодиоды p+-n-типа были изготовлены ионной имплантацией мышьяка в слои n-типа проводимости, легированные In с концентрацией (1-5)·1015 см-3. Измерены температурные зависимости обратных токов при нескольких напряжениях смещения, которые оказались почти на 2 порядка меньше, чем у n+-p-диодов.

Electrophysical properties of multilayered heteroepitaxial structures of Hg1-xCdxTe with x=0.3-0.4 grown by molecular beam epitaxy on silicon substrates are presented. The passivating effect of thin CdTe layers grown on top of the structures in single process is demonstrated. Comparison between experimental and theoretical temperature dependencies of reverse currents in n-on-p and p-on-n diodes fabricated by boron and arsenic ion implantation in vacancy-doped p-type and In-doped n-type Hg1-xCdxTe films, respectively, are presented. The influence of p-n junction position in double-layer heterostructure on temperature dependencies of reverse currents is examined. (C) 2016 WILEY-VCH Verlag GmbH & Co.

We investigated the temperature dependences of reverse current of "p-on-n" and "n-on-p" junctions fabricated in Cd0.39Hg0.61Te and Cd0.38Hg0.62 heterostuctures grown by MBE on Si substrates. The experimental data of reverse current through "p-on-n" junction in Arrhenius coordinates described by the diffusion of charge carriers in temperature range 210-330 K and carrier generation through the deep level located in the middle of the band gap in temperature range of 138-210K. The experimental data of reverse current through "n-on-p" junction in Arrhenius coordinates described by diffusion of charge carriers in temperature range 170-300 K and carrier generation through the deep level located in the middle of the band gap in temperature range 130-170K, At temperature range 77-130 K reverse current through "n-on-p" junction was constant and depended on bias voltage. (C) 2015 Elsevier B.V. All rights reserved.

The influence of electron energy quantization in a space-charge region on the accumulation capacitance of the InAs-based metal-oxide-semiconductor capacitors (MOSCAPs) has been investigated by modeling and comparison with the experimental data from Au/anodic layer(4-20 nm)/n-InAs(111)A MOSCAPs. The accumulation capacitance for MOSCAPs has been calculated by the solution of Poisson equation with different assumptions and the self-consistent solution of Schrödinger and Poisson equations with quantization taken into account. It was shown that the quantization during the MOSCAPs accumulation capacitance calculations should be taken into consideration for the correct interface states density determination by Terman method and the evaluation of gate dielectric thickness from capacitance-voltage measurements.

Results of studying the possibilities of passivating InAs surfaces by ultrathin oxide films (∼3 nm) in a glow-discharge plasma and producing tunnel MIS photodiodes on this basis are presented together with results of investigating the kinetics of oxidation and the chemical composition of oxide films formed. This is the first time when anhysteretic dependences of the capacitance on the bias are observed for InAs-based MIS structures at the liquid nitrogen temperature in a wide field range (from −7 · 106 to +5 · 106 V/cm). MIS structures are IR-photosensitive in the current mode. The estimated values of detectability are D* = 2.6·1012–8.2·1012 cm·Hz1/2·W−1 and D* = 1.5·1011 cm·Hz1/2·W−1 at temperatures of 78 and 198 K, respectively. The ampere-watt sensitivity value at a temperature of 78 K is 0.98 A/W, and the quantum efficiency is 0.43 (with no antireflecting coating of the InAs substrate and sapphire window).

The points of structuring hybrid IR FPAs based on charge injection devices (CID photodetector) are considered.Results of experimental examination of different thermographic systems based on InAs CID, linear and matrix hybrid modules, IR camera, IR microscope, high speed spectrometer are presented.It is shown that, in the short-wave IR range, it is possible to realize thermographic systems with temperature resolution (4-8) mK at effective frame frequency 1-10 Hz.

X-ray photoelectron spectroscopy and atomic force microscopy were used to examine the chemical composition and surface morphology of InAs(111)A surface chemically etched in isopropanol–hydrochloric acid solution (HCl–iPA) and subsequently annealed in vacuum in the temperature range 200–500°C. Etching for 2–30min resulted in the formation of “pits” and “hillocks” on the sample surface, respectively 1–2nm deep and high, with lateral dimensions 50–100nm. The observed local formations, whose density was up to 3×108cm−2, entirely vanished from the surface after the samples were vacuum-annealed at temperatures above 300°C. Using a direct method, electron beam microanalysis, we have determined that the defects of the hillock type includes oxygen and excessive As, while the “pits” proved to be identical in their chemical composition to InAs. Vacuum anneals were found to cause a decrease in As surface concentration relative to In on InAs surface, with a concomitant rise of surface recombination rate.

The effect of composition of the electrolyte used in producing a thin anodic oxide layer at the surface of a semiconductor substrate on the electrical properties of the InAs-SiO2-In2O3 metal-insulator-semiconductor structures is studied. It is shown that introduction of ammonium fluoride into the electrolyte results in the formation of an interface with the density of surface states below 5 × 1010 cm−2 eV−1, the built-in charge (4–5 × 1011 cm−2, and the maximum relaxation time of the surface potential.

The effect of composition of the electrolyte used in producing a thin anodic oxide layer at the surface of a semiconductor substrate on the electrical properties of the InAs – SiO 2 – In 2 O 3 metal–insulator–semiconductor structures is studied. It is shown that introduction of ammonium fluoride into the electrolyte results in the formation of an interface with the density of surface states below 5 × 10 10 cm –2 eV –1 , the built-in charge ( 4– 5 × 10 11 cm –2 , and the maximum relaxation time of the surface potential.

The multicomponent substance obtained by laser evaporation of the BN target under nitrogen was studied by X-ray fluorescence and X-ray absorption spectroscopy. The B K α spectra of the substance and boroncontaining compounds rh -BN, B 2 O 3 , and α-B were measured on a laboratory instrument using an ethyleneglycol distearate crystal as an analytical element; X-ray absorption spectra near the boron and nitrogen K edge were recorded on a BESSY synchrotron radiation station. The contents of the components in the synthesized substance were evaluated by decomposing the B K α spectrum into the spectra of the test boron-containing compounds. A comparison of the X-ray absorption spectra near the N K edge of the substance and rh -BN revealed that BN nanostructures obtained by laser evaporation were defective.

A design and parameters of the IR spectrograph based on an MS2004I monochromator-spectrograph and a hybrid microcircuit of a one-dimensional 1 × 384 InAs focal plane array for registration of fast processes (the registration time from 0.2 ms) are presented. The obtained spectral resolution is 0.3 nm/element at a wavelength of 1.7 μm. The wavelength range registered in a fixed position of the diffraction grating at this wavelength is 118 nm.

The focal plane array (IR FPA) on the basis of metal-insulator-structure (MIS) photodetectors on InAs auto-epitaxial substrate of 8x8 elements is designed and fabricated. It is shown, that the IR FPA provides definition of coordinate and time of arrival of optical pulse signals with energy 8x10(-17) J/element and accuracy not worse 100 ns.

Problems of using charge-injected devices in hybrid infrared focal plane arrays are considered.

Results of experimental investigation of thermography systems based on InAs CID elements of line and matrix hybrid modules (a thermal imager and IR microscope) are presented. Owing to a high time stability, in the short-wave IR range, the implemented thermography systems have a temperature resolution of ∼(4–8) mK for an effective frame frequency of 1–10 Hz.

Technology and design of linear 1x384 MIS photodetectors on InAs homoepitaxial substrate are developed. The experimental results on IR focal plane arrays (IR FPA) intended for rapid IR spectrometers with registration time 0,1 50 ms are presented.