Том 45, № 1 (2016)
- Жылы: 2016
- Мақалалар: 9
- URL: https://journals.rcsi.science/1063-7397/issue/view/11592
Article
Influence of the annealing temperature on the ferroelectric properties of niobium-doped strontium–bismuth tantalate
Аннотация
Characteristics of ferroelectric thin films of niobium-doped strontium–bismuth tantalate (SBTN), which were deposited by magnetron sputtering on Pt/TiO2/SiO2/Si substrates, are investigated. To form the ferroelectric structure, deposited films were subjected to subsequent annealing at 700–800°C in an O2 atmosphere. The results of X-ray diffraction showed that the films immediately after the deposition have an amorphous structure. Annealing at 700–800°C results in the formation of the Aurivillius structure. The dependences of permittivity, residual polarization, and the coercitivity of SBTN films on the modes of subsequent annealing are established. Films with residual polarization 2Pr = 9.2 µC/cm2, coercitivity 2Ec = 157 kV/cm, and leakage current 10–6 A/cm2 are obtained at the annealing temperature of 800°C. The dielectric constant and loss tangent at frequency of 1.0 MHz were ε = 152 and tan δ = 0.06. The ferroelectric characteristics allow us to use the SBTN films in the capacitor cell of high density ferroelectric random-access non-volatile memory (FeRAM).
Multilayer graphene-based flash memory
Аннотация
For the memory element based on a Si/HfO2/multilayer graphene/SiO2/Si structure, the write/erase and charge storage characteristics are evaluated. A sufficiently large work function of electrons in multilayer graphene (MLG) makes it possible to increase the time of storing the charge injected into it. Using MLG in flash memory devices allows one to increase the speed and/or reduce the voltage of reprogramming such devices.
Simulation of the spectroscopic response and electron dynamics in a double quantum dot
Аннотация
We present the results of the numerical simulation of the dependence of the absorption spectrum of a single-electron semiconductor double quantum dot placed in a microcavity on structural parameters and the time dependence of populations of quantum dot states. The investigated physical system can be used for quantum information coding and processing. Initialization and one-qubit operations correspond to the redistribution of populations of localized states of a quantum dot under the action of laser and cavity optical fields.
Formation and certain properties of zinc chalcogenide nanolayers on semiconductor matrices
Аннотация
The generalized results on the synthesis of zinc chalcogenide ultrathin layers using an atomic layer deposition on the surface of silicon and AIIIBV compounds have been presented. The main regularities inherent in the chemosorption of the components and the conditions required for the layered mechanism responsible for the formation of nanostructures of the compounds mentioned are established. The electrical properties of the synthesized nanostructures have been estimated.
System-on-chip: Specifics of radiation behavior and estimation of radiation hardness
Аннотация
The analysis results of typical radiation faults of the system-on-chip have been presented. The specifics of digital, analog-to-digital (mixed), and microwave system-on-chip are considered. A set of the basic parameters-criteria for the radiation hardness of system-on-chip of various classes is determined. Methodical and technical designs for controlling the operability of the System-on-chip by carrying out radiation tests are proposed.
Effect of a diamond heat spreader on the characteristics of gallium nitride-based transistors
Аннотация
A problem, which concerns the effect of the diamond heat-spreading layer on the temperature and voltage-current characteristics of gallium nitride (GaN) high-electron-mobility transistors (HEMTs) is solved for the first time in a hydrodynamic model (which includes the continuity equation, Poisson equation, and equations for electron and lattice temperatures). The mechanism of the occurrence of peak electron and lattice temperatures (hot spots) is analyzed. It is shown that introducing a heat spreader considerably reduces the maximum temperature (by 263 K for a sapphire substrate and by 163 K for a silicon carbide substrate) and improves the voltage-current characteristics. The effectiveness of the heat spreader is evaluated depending on its thickness, gate size, and substrate material to find the optimum design.
Influence of ionizing radiation on the parameters of an operational amplifier based on complementary bipolar transistors
Аннотация
The influence of a 4 MeV energy electron flux and 60Co gamma radiation with an average energy of 1.25 MeV on the characteristics of silicon complementary bipolar transistors (BTs) and a wide-band operational amplifier (OA) has been studied. It is established that an action of FE = 3×1014 el/cm2 electron fluence causes a decay in the common–emitter current gain (ß) of 61% for NPN and 66% for PNP transistors, as well as a decrease in the maximum value of the transition frequency (fT) of 12% for NPN and by 4% for PNP transistors. When the absorbed dose DG amounts to 3 Mrad, a decrease in ß by 39% for NPN and by 44% for PNP transistors, and in fT of 10% for NPN and 11% for PNP transistors is observed. Despite the substantial decay in ß of transistors, the OA circuitry provided the retention of the operation speed and a small decrease in the offset voltage (about 1.5 mV) in the irradiation range mentioned. The circuitries of OA cascades and the experimental characteristics of the BTs and OAs are presented.
The circuit and functional blocks for radiation-hard transceiver LSICs in SOI CMOS
Аннотация
The results of designing a set of basic circuit and functional blocks (amplifying, oscillating, mixing, etc.) to construct the radiation-hard transceiver CMOS Silicon-on-Insulator (SOI) large-scale integration circuits (LSICs) are presented. It was established experimentally that the test chips of the circuit and functional blocks (CFBs) produced by domestic CMOS SOI technologies at a feature size of 0.35 µm are functionally operable in the frequency range of 1 MHz to 1.8 GHz, and the values of the main parameters are close to the calculated ones. The results of the experimental research on the hardness of the developed CFBs to pulse and dose impact of ionizing radiation are presented and the hardness levels were evaluated.