Topological thermal compensation in a hybrid-film micro thermostat containing thermally stable substrate

The application of a minimal statistical error effect when controlling the temperature under topological thermal compensation of thermally sensitive electric radio components on the construction level in order to minimize the temperature inaccuracy of thermostatically controlled radio electronic devices in a hybrid-film thermostat with thermally stable substrate is considered. Numerical modeling of the two-dimensional non-stationary temperature fields of a thermally stable substrate taking into account real mechanisms of heat exchange for a proportional temperature controller is conducted.     

Active elements on a basis of ZnO nanorods for energy harvesting devices

It is represented the research of piezoelectric properties of nanorods and their application in energy harvesting devices. According to the simulation results with method of finite elements the value of electromechanic coupling coefficient of monolayer from ZnO nanorods is greater than one in compare to uniform film application. The sample manufacturing method consists of application of traditional microelectronic technique for shaping of top and bottom electrodes and also application of two-steps low-temperature chemical synthesis for ZnO nanorods. To provide acoustic perturbation of the sample the piezoceramic element is used in multilayer structure fixed on the glassceramic substrate. The results are obtained for two measurement modes, providing oscillations perturbation by rectangular pulses source and by harmonic generator. Obtained results demonstrate high efficiency of piezoelectric transformation for monolayer, which consists of ZnO nanorods that is possible to be used in different self-powered devices.     

Application of functional spaces theory in the simulation of nonlinear radio engineering devices

The problem of simulation of nonlinear radio engineering devices is considered on the basis of the functional analysis theory. It has been shown that in particular cases such approach results in known techniques of harmonic balance and Volterra series. The new algorithm, which has better computing characteristics compared with techniques of harmonic balance and of Krylov subspaces, has been developed.     

Estimation of efficiency and noise-immunity of radio communication system on a basis of linguistic diagnosis

It is shown a possibility of linguistic diagnosis for efficiency and noise immunity estimation of radio communication system. On a basis of direct experts questioning membership functions for one of the system parameters are built.     

铂电阻测温非线性补偿的研究

针对铂电阻在测量温度中存在的非线性,分析了产生非线性误差的主要原因,讨论了改善铂电阻线性度以及消除测量电路非线性误差的方法,为铂电阻的非线性补偿方法提供了理论依据.最后给出误差分析和实验结论.     

Processing of signals from land-based radio emission sources in a monostatic air-borne monitoring system

The problem of processing of signals from fixed land-based radio emission sources (RESs) measured in a monostatic air-borne radio monitoring system is considered. On the basis of the Bayesian approach, an optimal joint procedure for RES identification from radio measurements, estimation of RES state coordinates, and RES type recognition is developed. Relationships obtained in the synthesis of the joint procedure are analyzed. The results of application of the joint procedure are compared with the results obtained by independently synthesized algorithms for RES identification, estimation of RES state coordinates, and RES type recognition.     

Injection lasers with a broad emission spectrum on the basis of self-assembled quantum dots

It is shown that one can attain simultaneously width of the lasing spectrum in excess of 15 nm and average spectral power density higher than 10 mW/nm in injection continuous-wave lasers based on self-assembled quantum dots and emitting in the wavelength range of approximately 1.3 μm.     

Effect of high temperature annealing on tunnel oxide properties in TANOS devices

We investigate the effect of high temperature Post-Deposition Annealing of Al₂O₃ on the tunnel oxide of TANOS-like non-volatile memories. We found that, when temperature steps above 850 °C are applied after the stack deposition, a transition layer is forming by the intermixing of the Si₃N₄ with the upper part of the underneath SiO₂. We found that this transition layer has worse dielectric properties as compared to SiO₂, altering in a not-negligible way the performance of TANOS memories, and in particular severely penalizing retention.     

Rare-earth elements in the technology of III–V compounds and devices based on these compounds

Semiconductors - The results of our studies concerned with the use of rare-earth elements in the liquid-phase epitaxial technology of the InP, InGaAsP, InGaAs, and GaP compounds and with the...     

低温对毛果杨韧皮部筛分子胼胝质沉积的影响

利用光学显微镜和扫描电子显微镜观察了低温对毛果杨韧皮部筛分子胼胝质沉积以及筛域结构的影响。观察结果显示,低温(4℃)处理1周后,毛果杨韧皮部筛分子的胼胝质沉积明显减少,筛孔的面积也呈现降低趋势。结果表明低温抑制了胼胝质在筛分子中的沉积,已有的胼胝质也快速降解消失,胼胝质沉积变化伴随着筛孔面积改变。研究结果将有助于揭示杨树年生长周期过程中环境因素对于韧皮部筛分子结构与功能的调控机制。     

Effects of turbulence in a planetary atmosphere on radio occultation

There has been considerable interest in the amplitude and phase fluctuations of the radio signal received from a flyby spacecraft during occultation by a planetary atmosphere. For planetary flyby missions, the Fresnel-zone size exceeds the outer scale size of turbulence, and existing formulations for the frequency spectra of the amplitude and phase fluctuations are inadequate because they do not account for the inhomogeneity of the turbulence in the direction transverse to the propagation path. In this paper, the formulation is given for the correlation functions for the log-amplitude and phase fluctuations of both spherical and plane waves propagating in a turbulent medium whose correlation function for refractive index fluctuations is described by the product of a function of the average coordinate and a function of the difference coordinate. The results are applied to radio occultation of a flyby space probe by the atmosphere of Venus, assuming that the turbulence in the atmosphere exists as a layer, that it is localized, isotropic, and smoothly varying, and that the localized turbulence is described by the Kolmogorov spectrum. Closed-form solutions for both variances and frequency spectra of the log-amplitude and phase fluctuations are obtained using Rytov's method, and it is seen that the shape of the frequency spectra depends a great deal on the characteristics and extent of the turbulence.     

Electroluminescent studies of emission characteristics of InGaAsN/GaAs injection lasers in a wide temperature range

Light-current, spectral, and far-field characteristics of InGaAsN injection lasers on GaAs substrates were studied in a wide temperature range (77–300 K) at various driving current densities. The increase in indium content in InGaAsN solid solution results in a modification of the QW structure, which is manifested in the spontaneous formation of InGaAsN nanoclusters. These changes result in N-shaped temperature dependences of the threshold current density and slope efficiency.     

Determination of the channel temperature in a GaAs MESFET from the emission transients of deep traps

A technique is proposed by which the self-heating in the channel of a GaAs MESFET may be determined from the observation of thermally activated transients due to the emission of electrons from indigenous deep traps. The advantage of this technique over others is that its spatial resolution is automatically equal to the channel length. The feasibility of the technique has been demonstrated on 1 micron gate-length small-signal devices, for which a thermal resistivity of 200°C mm/W was found.     

Logic synthesis and circuit modeling of a programmable logic gate based on controlled quenching of series-connected negative differential resistance devices

The circuit concept of programmable logic gates based on the controlled quenching of series-connected negative differential resistance (NDR) devices is introduced, along with the detailed logic synthesis and circuit modeling. At the rising edge of a clocked supply voltage, the NDR devices are quenched in the ascending order of peak currents that can be reordered by the control gates and input gates biases, thus, providing programmable logic functions. The simulated results agree well with the experimental demonstration of the programmable logic gate fabricated by a monolithic integrated resonant tunneling diode/high electron mobility transistor technology.     

A specimen-drift-free EDX mapping system in a STEM for observing two-dimensional profiles of low dose elements in fine semiconductor devices

We developed a specimen-drift-free energy-dispersive X-ray (EDX) mapping system in a scanning transmission electron microscope (STEM) to improve the sensitivity and spatial resolution of EDX elemental mapping images. The amount of specimen drift was analysed from two STEM images before and after specimen drift by using the phase-correlation method, and was compensated for with an image-shift deflector of the STEM by the displacement of the scanning electron beam. We applied this system to observe the two-dimensional distribution of low dose arsenic in silicon semiconductor devices. The sensitivity of the elemental mapping was improved to several tenths atomic % for arsenic atoms while maintaining a spatial resolution of 2 nm.     

The effect of post-oxygen-implant annealing temperature on the channel mobilities of CMOS devices in oxygen-implanted silicon-on-insulator structures

The effects of post-oxygen-implant annealing temperature on the characteristics of MOSFET's in oxygen-implanted silicon-on-insulator (SOI) substrates are studied. The results show significant improvements in the electron and hole mobilities near the silicon/buried-oxide interface and in the electron mobility of the front-gate n-channel transistors in SOI substrates with higher post-oxygen-implant annealing temperature. The improvements in the transistor characteristics hence are attributed to the annihilation of oxygen precipitates and the reduction of defect density in the residual silicon film. By comparing the ring oscillators fabricated in SOI substrates annealed at 1150°C and 1250°C after oxygen implantation, a speed improvement of 15 percent is observed in substrates annealed at higher temperature.     

Effect of the pre-gate oxide cleaning temperature on the reliability of GOI and devices performances in deep submicron CMOS technology

This paper reports the impacts of the pre-gate oxide cleaning on the statistic fluctuations of a deep submicron CMOS devices’ saturation current, leakage current, threshold voltage, and gate oxide integrity (GOI) in detail. These statistic distributions are based on a foundry’s batch production line. This study concludes that the pre-gate oxide hot water clean enhances silicon surface’s micro-roughness and stress effects, thus are responsible to the higher fluctuations of devices performance distributions. Similar results were found in the GOI of the thin gate oxide. The micro-roughness and stress effects of silicon surface were evaluated systematically through atom force microscope (AFM) and thin film stress measurement system, and their mechanisms are interpreted comprehensively with schematic models.     

Display devices based on low-voltage excitation of ZnO in a gas plasma

Using a gas plasma as a source of free electrons, a brightness of 60 fL is obtained from an extended layer of ZnO phosphor with about 5 V applied to it. The phosphor efficiency, >10 lm/W, shows little change during 5000 h of operation. For display purposes devices have been constructed incorporating multiple phosphor-coated anodes whose potentials are controlled by low-voltage semiconductor circuits.     

Secondary information processing in angular-measuring systems on a basis of invariants

On a basis of complete set of independent invariants problems of bearing angle match and identification of targets movement model are solved applying to multi-position angular-measuring system. It is shown application of invariants of passive location provides maximal possible decentralization of measurements processing.