In this paper, the surface morphology of InAlAs layers deviating from the lattice-matched composition with an InP substrate is studied. The possibility of forming an array of nanopits uniform in size and shape on the surface of the InAlAs layer is demonstrated. A linear relationship between the size of pits on the surface of a InAlAs layer and its thickness is shown.

A brief overview is presented of results obtained at the Rzhanov Institute of Semiconductor Physics in the development of photon detectors and emitters promising for use in quantum cryptography systems, along with miniature quantum frequency standards based on the effect of coherent population trapping.

The influence of the valence band structure on the optical properties of quantum wells with a parabolic potential, consisting of AlxGa1-xAs and In1-xGaxAsyP1-y alloys, is studied and compared. The distribution of photogenerated carriers over the parabolic potential is found to be responsible for specific selection rules: the recombination due to only odd-indexed confined levels is observed. The reason for this is the accumulation of photogenerated holes at the center of the parabolic potential, which results in interband electron-hole recombination occurring at the center of the parabolic quantum wells. Furthermore, a specific valence band structure is found to be responsible for the magnetic-field-induced change in the photoluminescence circular polarization. In particular, at a certain magnetic field, the hybridization of the states of a heavy hole and a light hole results in the intersection of Landau levels with different spins, which leads to the observed change in the circular polarization of photoluminescence. The processes of long-term spin relaxation of heavy holes in both studied parabolic quantum wells are demonstrated, and the corresponding times are obtained.

The results of a study of the optical characteristics of non-classical light sources based on single In(Ga)As quantum dot grown on a (111)B GaAs substrate are presented. The single-photon nature of the radiation is confirmed by measuring and analyzing the second-order correlation function g(2)(τ), g(2)(0)=0.033 ± 0.027, and the degree of indistinguishability of sequentially emitted single photons is (41 ± 10 )%.

The results of the development of vertical-cavity surface emitting lasers based on Al $${}_{x}$$ Ga $${}_{1-x}$$ As and In $${}_{y}$$ Ga $${}_{1-y}$$ As solid solutions are presented. Developed lasers demonstrate stable single-mode operation at wavelengths of 794.9 and 894.6 nm, which offers the prospects of their applications in miniature quantum frequency standards based on $${}^{87}$$ Rb and $${}^{133}$$ Cs.

In this work, the process of phosphorus desorption from epi-ready InP(001) substrates during high-temperature annealing in an arsenic flux was experimentally investigated. An InPAs solid solution and InAs islands were formed on the surface upon annealing. The composition of the solid solution, the surface area fraction occupied by InAs islands, and its height depend on the annealing temperature. The phosphorus desorption rate was determined from the dependence of the arsenic atoms number on the substrate surface on the annealing temperature and the holding time in the arsenic flux. The phosphorus desorption rate increased from 6.03×1010 s−1⋅ cm−2 at an annealing temperature of 500 °C to 4.38×1011 s−1 ⋅ cm−2 at 540 °C. The activation energy of the phosphorus desorption process was 2.7 ± 0.2 eV.

Changes in the structure and elemental composition of the surface of the epitaxy-ready InP(001) substrate in an As flux in ultrahigh vacuum are studied in situ by the reflection high-energy electron diffraction (RHEED) technique. It is shown that, during annealing of the oxide layer at the surface, an InP 1 – x As x layer is formed as a result of the substitution of phosphorus by arsenic. The dependence of the degree of substitution on the annealing temperature and time is established. The degree of the substitution of phosphorus by arsenic in the surface layer is 7% at the annealing temperature 480°C and, reaches 41% at the temperature 540°C. The annealing time influences the degree of substitution only slightly.

We report experimental study of phosphorus desorption from epi-ready InP(001) substrates during high-temperature annealing in an arsenic flux. InPAs solid solution and InAs islands form on the surface in the process of annealing. The original method is proposed for determining the number of phosphorus atoms desorbing from the surface by determining the number of arsenic atoms in the InPAs solid solution and InAs islands. The flux of phosphorus desorbing from the surface increases from 1 · 10−4 monolayer · cm−2· s−1 at 500◦C annealing temperature to 7.3 · 10−4 monolayer · cm−2· s−1 at 540◦C. The activation energy of the phosphorus desorption process is 2.7 ± 0.2 eV

The design and fabrication technology of high-power Schottky-barrier microwave mesa photodiodes from 10 to 40 μm in diameter back-illuminated through the substrate are described. The diodes were made on MBE-grown InAlAs/InGaAs/InP heterostructures. The operating frequency of photodiodes 10 μm in diameter has been found to be 40 GHz, and the maximal microwave output at 20 GHz for photodiodes 15 μm in diameter have been found to reach 58 mW. The coefficient of amplitude-to-phase conversion has been determined to be 1.5 rad/W. This value outperforms the available literature data and makes the given design of photodiodes promising for systems of analog microwave signal generation and transmission, which are very sensitive to phase noise.

We report experimental study of phosphorus desorption from epi-ready InP(001) substrates during high-temperature annealing in an arsenic flux. InPAs solid solution and InAs islands are formed on the surface in the process of annealing. The original method is proposed to determine the amount of phosphorus atoms desorbing from the surface by determining the amount of arsenic atoms in the solid solution of InPAs and InAs islands. The flux of phosphorus desorbing from the surface increases from 1·10 -4 monolayer · cm -2 ·s -1 at 500 o C annealing temperature to 7.3·10 -4 monolayer · cm -2 · s -1 at 540 o C. The activation energy of the phosphorus desorption process is 2.7±0.2 eV. Keywords: InP, annealing, desorption, activation energy.

We report experimental study of the transformation of the epi-ready InP(001) surface during annealing in an arsenic flux. Using the RHEED method, it was shown that an InP1−xAsx layer is formed on the surface. The amount of arsenic substitution for phosphorus at different annealing temperatures was determined, which is 7% at an annealing temperature of 480◦C and increases to 41% with an increase in the annealing temperature to 540◦C. The annealing time has little effect on the degree of substitution.

Возможность создания в одном технологическом процессе гетероэпитаксиальных структур (ГЭС) для излучающих, передающих, модулирующих и принимающих элементов, делает InP ключевым материалом для интегральных систем радиофотоники [1, 2]. Предэпитаксиальная термическая очистка подложек InP в сверхвысоком вакууме ростовой камеры в потоке мышьяка, позволяет получить резкую гетерограницу слой/подложка и избежать неконтролируемого встраивания фосфора в слои InAlAs/InGaAs, согласованные по параметру кристаллической решетки с подложкой [3]. Однако, в процессе отжига на поверхности формируются InAs островки, которые образуют дефекты на гетерогранице. Методом дифракции быстрых электронов на отражение (ДБЭО) in situ изучен процесс удаления оксида с поверхности epi-ready InP(001) подложки в потоке мышьяка в сверхвысоком вакууме.

Vibrational properties of self-assembled InAs quantum dots (QD’s) embedded in AlAs and aluminium oxide were studied by Raman spectroscopy. The InAs/AlAs QD structures were grown by molecular beam epitaxy on GaAs (001) substrates. The following main features of the phonon spectra of InAs/AlAs QD nanostructures were observed: 1) asymmetric lines of QD LO phonons affected by strain, confinement and size inhomogeneity of QD’s; 2) confined phonons of InAs wetting layer (WL); 3) two bands of interface phonons in the AlAs frequency region, attributed to modes associated with the planar interface WL/AlAs matrix and the three-dimensional QD/matrix interface; 4) doublets of folded acoustic phonons caused by periodicity in the multilayer QD structures. The influence of growth temperature, varied from 420 to 550°C, on the morphology of QD’s was investigated. QD’s grown at 420°C are found to have the smallest size. Increasing the temperature up to 480°C leads to the formation of larger InAs islands and improved size homogeneity. Further temperature elevation (above 500°C) causes partial re-evaporation of InAs leading to a decrease of QD size and density, and, finally, their complete disappearance. InAs QD’s embedded in aluminium oxide were fabricated by selective oxidation of the AlAs matrix in self-assembled InAs/AlAs QD’s. Micro-Raman spectroscopy data show that depending on oxidation conditions (humidity, temperature) InAs QD’s in an oxide matrix can be even more strained than before oxidation, or become fully relaxed. At the boundaries of oxidized/non-oxidized areas the presence of amorphous and crystalline As clusters is evident.

The paper states the operating principles of subminiature semiconductor emitters and offers the research results of the performance for those emitters that were developed and manufactured at the Rzhanov Institute of Semiconductor physics of SB RAS over the last three years. Single photon emitter based on Al $${}_{x}$$ In $${}_{1-x}$$ As/Al $${}_{y}$$ Ga $${}_{1-y}$$ As quantum dots has been developed. Hanbury Brown and Twiss experiment has been carried out to measure the photon statistics. The photon correlation function demonstrates a clear photon antibunching effect ( $$g^{2}$$ (0) $$\approx$$ 0.04), which is a direct evidence of single photon emission by single Al $${}_{x}$$ In $${}_{1-x}$$ As quantum dots. The results of developing single-mode vertical-cavity surface-emitting lasers with a wavelength of 794.8 nm future-oriented for application in chip-scale atomic clock and operating at the transition 5S $${}_{1/2}\to$$ 5P $${}_{1/2}$$ of Rb $${}^{87}$$ are reported.

Описаны конструкция и технологии изготовления мощных СВЧ-мезафотодиодов с барьером Шоттки диаметром от 10 до 40 μm и обратной засветкой через подложку на основе гетероструктур InAlAs/InGaAs/InP, выращиваемых методом молекулярно-лучевой эпитаксии. Рабочая частота фотодиодов диаметром 10 μm составляет 40 GHz, а максимальная выходная СВЧ-мощность на частоте 20 GHz для фотодиодов диаметром 15 μm достигает 58 mW. Коэффициент амплитудно-фазового преобразования составил 1.5 rad/W, что превосходит литературные данные и делает данную конструкцию фотодиодов перспективной для применения в системах генерации и передачи аналоговых СВЧ-сигналов с высокими требованиями к фазовым шумам. Ключевые слова: мощные СВЧ-фотодиоды, гетероструктуры InAlAs/InGaAs, барьер Шоттки, планарная технология.

A new type of AlGaAs/InGaAs/GaAs heterostructures with energy barriers formed in the AlGaAs transistor layers adjacent to the InGaAs channel, modulation-doped with donors and acceptors is presented. The height of the barriers associated with the potential of the space charge region in AlGaAs layers reaches 0.8 eV, which makes it possible to double the concentration of electrons in the channel, prevent the transition of hot electrons heated by the electric field into surrounding layers, and increase their saturation drift velocity by around $$1.2{-}1.3$$ times. As a result, microwave power output density of the transistor exceeded the world level by more than 50 $$\%$$ .

The results of the development and implementation of a single photon source based on a bottom semiconductor Bragg reflector, top deterministic GaAs microlens structures and a single (111) In(Ga)As QD are presented. The structure of the microcavity ensures effective pumping of a single (111) In(Ga)As QD and high emission output efficiency, a clear single-photon emission was detected with a second-order correlation function at zero delay g((2))(0) = 0.07. A system of QD's on the basis of AlXIn1-XAs/AlYGa1-YAs solid solutions has been studied. The usage of broadband AlXIn1-XAs solid solutions as the basis of quantum dots makes it possible to expand considerably the spectral emission range into the short-wave region, including the wavelength region near 770 nm being of interest for the design of aerospace systems of quantum cryptography. The optical characteristics of single AlXIn1-XAs quantum dots grown according to the Stranski-Krastanov mechanism are studied by the cryogenic microphotoluminescence method.

AbstractGrowth-related structural defects present on the surface of InAlAs layers grown by molecular beam epitaxy on InP(001) substrates influence the temperature dependences of the current–voltage characteristics of Au/Ti/InAlAs Schottky barriers. It is established that these defects in the form of pits cause the appearance of regions with reduced barrier height. At a surface density of ≥10^7 cm^–2, these defects significantly influence the parameters of the Schottky barriers at temperatures below 200 K.

The design and technology of manufacturing of high-power Schottky barrier UHF-photodiodes with microstrip contacts made on the basis of InAlAs/InGaAs heterostructures have been developed. The operation frequency of 15-micron diameter photodiodes is greater than 25 GHz, while the maximum attainable output UHF power exceeds 50 mW at a frequency of 20 GHz. This allows one to utilize these photodiodes in analog fiber-optic UHF signal transmission lines as well as for generation and processing of UHF signals by optical techniques in radar systems and UHF measurement and instrumentation.

В работе показана зависимость плотности структурных дефектов в решёточно-согласованныхслоях InAlAs от условий отжига подложки (001)InP в потоке As. Отработана технология отжига, наоснове которой синтезированы структуры мощных СВЧ фотодиодов и модуляторов.Гетероструктуры на основе слоев InAlAs решёточно-согласованных с подложкой (001)InP, внастоящее время привлекают большое внимание исследователей из-за применения в широкомспектре современных приборов[1]. Характеристики приборов напрямую зависят от качествагетероэпитаксиальных слоёв [2]. В работе показана зависимость плотности структурных дефектов врешёточно-согласованных слоях InAlAs от условий отжига подложки InP в потоке As.Образцы выращены методом MЛЭ на установке Riber Compact-21T, оснащенной с системойдифракции быстрых электронов на отражении. Для роста использовались полуизолирующиелегированные Fe (001) InP подложки фирмы AXT.Подложки отжигались в широком диапазоне температур 500-560°C, для удаления окисного слоядо появления сверхструктуры (4х2). Отжиг проводился в потоке мышьяка, препятствующемразложению подложки и образованию индиевых капель. Поток мышьяка варьировался в широкомдиапазоне (0.5-7)*10-5 Торр. В процессе отжига происходит замещение атомов фосфора атомамимышьяка и на поверхности подложки образуется слой InAs. Методом сканирующей электронноймикроскопией (СЭМ) в режиме энергодисперсионной спектроскопии (EDS) было показано, что этотслой может достигать нескольких нанометров, в зависимости от условий отжига. Постояннаякристаллической решётки InP составляет 5.869Å, тогда как InAs 6.058Å. Такая существенная разницаприводит к решёточному рассогласованию на начальных этапах роста слоёв InAlAs и возникновениюнапряжений, которые релаксируют в виде прорастающих дислокаций. На АСМ картинахповерхности наблюдаются структурные дефекты в виде ямок сформированные комплексамидислокаций. Плотность ямок на поверхности слоя InAlAs увеличивается с увеличением толщиныслоя InAs на гетерогранице слой/подложка, и может достигать 10-9см2. Толщина слоя InAs зависит оттемпературы отжига и времени экспозиции подложки в потоке мышьяка. В работе экспериментальнополученные оптимальные условия отжига: температура подложки <520℃, эквивалентный потокмышьяка <1,6x10-5Торр, время экспозиции при формировании сверхструктуры (4x2) <30 секунд. Приэтих условиях с поверхности удаляются окислы, но не формируется существенный слой InAs, чтопозволяет синтезировать высококачественные слои InAlAs для оптоэлектронных приборов. Намибыли получен мощные СВЧ фотодиоды 1.55 мкм спектрального диапазона, с частотами до 40Ггц, атакже продемонстрированы гетероэпитаксиальные структуры для модуляторов