Volume 45, Nº 7 (2016)
- Ano: 2016
- Artigos: 18
- URL: https://journals.rcsi.science/1063-7397/issue/view/11624
Article
Mathematical simulation of the influence of the doping concentration on the drain current of an SOI field-effect hall sensor
Resumo
The influence of the doping concentration in the active layer and in the bulk substrate on the drain current of a silicon-on-insulator (SOI) field-effect Hall sensor (FEHS) using Sentaurus TCAD is studied. At the initial stage, the numerical model is corrected by comparing the transfer current-voltage characteristics of the calculation and the experimentally measured SOI FEHS sample. It is shown that, under low concentrations in the active layer, the drain current depends on the capacity of the front gate, while the doping concentration in the bulk substrate affects the drain current only when the device is operating in depletion mode.
Formation of nanosized elements of microwave transistor gates by ion beam lithography
Resumo
A technique for forming a nanosized gate of a high-power microwave transistor is proposed. The optimal exposure parameters of 950-PMMA-A2 and ELP-20 resists are established. The technological route of ion beam lithography with the use of multilayer resists is investigated. A technique for fabricating a continuous mesh of earthed alignment marks formed on the ion-sensitive resist to visualize the alignment marks on a dielectric substrate by ion microscopy is developed.
Study of RF transistor with submicron T-shaped gate fabricated by nanoimprint lithography
Resumo
The results devoted to the development of a method for creating an RF transistor, in which a T-shaped gate is formed by nanoimprint lithography, are presented. The characteristics of GaAs p-HEMT transistors have been studied. The developed transistor has a gate “foot” length of the order of 250 nm and a maximum transconductance of more than 350 mS/mm. The maximum frequency of current amplification ft is 40 GHz at the drain-source voltage VDS = 1.4 V and the maximum frequency of the power gain fmax is 50 GHz at VDS = 3 V.
TCAD leakage current analysis of a 45 nm MOSFET structure with a high-k dielectric
Resumo
The models of electrophysical effects builtinto Sentaurus TCAD have been tested. The models providing an adequate modeling of deep submicron high-k MOSFETs have been selected. The gate and drain leakage currents for 45 nm MOSFETs with polysilicon gate and SiO2, SiO2/HfO2 and HfO2 gate dielectrics have been calculated using TCAD. It has been shown that the replacement of the traditional SiO2 gate oxide by an equivalent HfO2 dielectric reduces the gate leakage current by several orders of magnitude due to the elimination of the impact of the tunneling effect. Besides, the threshold voltage, saturation drain current, mobility, transconductance, etc., degrade within a range of 10–20%.
Features of the effect of the supply current on the operation mode of an oscillator based on an IMPATT diode taking into account the reflected signal
Resumo
A theoretical investigation of the IMPATT diode supply current on the operation mode of a generator is out. As additional parameters affecting the operation mode, the coefficients of signal reflection from the inhomogeneity in the output transmission line and the delay time of this signal have been analyzed. It is shown that the following modes of synchronization may appear at various relations between these parameters: with an instability of the amplitude, multifrequency mode, dynamic chaos mode, single-frequency mode, and oscillation suppression mode. Based on the solution to the autogenerator equation, the possible operation modes of a generator based on the IMPATT diode were analyzed. The results make it possible to assess the range of parameters where a negative effect upon the operation mode of the oscillator will be absent and the ranges of the oscillator’s parameters when the mode of dynamic chaos can be obtained.
A method for calculating the thermal characteristics of silicon TVS-diodes in the pulse mode
Resumo
The dependence of the thermal characteristics of TVS-diodes during the passage of the pulse overload has been studied. The time dependences of the pulse voltage limitation and current are analyzed. Based on the analysis of the dependences, the thermal characteristics of the TVS-diode are calculated. It is shown that the parameters of the TVS-diodes deteriorate on reaching a current density of 160–300 A/cm2 and critical temperature of 250–300°С. The dependences of the thermal resistance and critical temperature of the TVS-diodes on the current density and the pulse duration are presented.
320 × 240 CMOS array for the spectral range of 3–5 μm based on PtSi photodiodes
Resumo
The results of research and development of a 320 × 240 platinum silicide focal plane array (FPA) for the spectral range of 3–5 μm are presented. The development is based entirely on CMOS technology. It is shown that the FPA makes it possible to adjust the photosignal accumulation time at a fixed frame rate and subtract the background constant component in the output device.
Efficiency of frequency transformation on MOS transistors with a built-in channel under intensively handicapped radioreception
Resumo
An algorithm and a technique are developed for finding the maximum values of the target current components in a MOS transistor with an n-type built-in channel depending on the submicron and nanoscale topological norms for a frequency transformer in the presence of intensive noise at its input. The spectral making components of the intermediate frequency are evaluated and analyzed for the given amplitudes of the generator, signal, and handicap. The behavior of the n-MOS transistors designed according to the GPDK045 and GPDK0990 technological norms is investigated.
Development and research of MIS varicaps with charge transfer
Resumo
A new type of a double-electrode MIS varicap with a carrier transfer has been proposed. It is shown that in a device of this type, there are no negative effects associated with the processes of thermal generation and accumulation of minority carriers. This makes it possible to increase the limiting frequency and improve the temperature stability of varicap operation. Two designs of the device are considered. The characteristics of the varicaps that were measured experimentally agree with the results of the calculations.
Intelligent system and electron components for controlling individual heat consumption
Resumo
An intelligent system and its electron components are developed that implement an innovative method for measuring individual heat consumption. For the intelligent system and its electron components, original design-technological, circuit, hardware, and software solutions are proposed. The methods and mathematical models for evaluating individual heat consumption are developed and validated.
Refined model of low-impedance film resistors with a comb-like structure
Resumo
Using the methods of finite element and conformal mapping, analytical models with low and ultralow resistance of the film resistors of the main types of comb-like (interdigital) structures with an arbitrary ratio between the surface resistivities of resistive and conductive films have been worked out. In the resultant resistance, the resistances of comb-like and connecting electrodes are taken into account, as well as the additional resistance caused by the passage of the current from the conductive to the resistive film and vice versa. The conditions under which an interface between the films can be treated as an equipotential surface are revealed. An equivalent circuit of low-impedance comb resistors, which are used as the sensors of the current in the circuits of stabilization and control, as well as thermal and current protection.
Double stage low-frequency noise equivalent circuit of green InGaN LEDs for description of noise characteristics
Resumo
To explain the current dependences of the mean-square value of low-frequency (LF) noise current in green InGaN light emitting diodes (LEDs), a double stage low-frequency noise equivalent circuit of the LED is proposed. It is shown that the nonmonotonic dependence of the LF noise on the injection current in the LED can be explained by the effect of two LF noise generators: a noise current generator, which is localized near the heterojunction and is determined by tunnel-recombination processes at the interface, and a generator determined by recombination processes in the active region of the structure.
Computer-aided design flow of devices for generating and processing signals for satellite navigation systems
Resumo
The models of the analog and digital parts of a GLONASS receiver obtained using a Matlab Simulink simulation environment are presented. The possibilities of estimating the characteristics of the analog part of the GLONASS receiver in the ADS CAD software are investigated. The design flow is proposed based on the construction of a cross-cutting radio channel model using a different CAD software. The considered models expand the opportunities for thoroughly investigating radio channels in the field of satellite navigation and improving the existing devices for receiving and processing GLONASS signals.
Design of a multielement infrared thermal detector
Resumo
Solutions obtained in the course of designing integral multielement thermal detectors, in which an array of detector elements of a thin ferroelectric film is formed, are presented. Based on the tools of the CAD system, the parameters of the signal readout circuit of the pyroelectric detectors are optimized and a set of documents for manufacturing an integrated circuit (IC) of the detector with design rules of 0.18 μm is formed. A distinctive feature of the proposed development is the possibility of the parametric trimming of the conversion coefficients due to the repolarization of each element of the ferroelectric array in the process of calibration.
Narrowband microwave microelectromechanical switch on gallium arsenide substrates for operation in a frequency band of 10–12 GHz
Resumo
Discrete electrostatic microwave microelectromechanical switches on gallium arsenide wafers are designed and fabricated. The possibility of integrating the switches in one circuit with monolithic integrated circuits of transreceiving devices fabricated in one production cycle is estimated.
Simulation of characteristics and optimization of the constructive and technological parameters of integrated magnetosensitive elements in micro and nanosystems
Resumo
The features of the technology computer aided design of integrated magnetosensitive elements in micro and nanosystems are considered. The results of the simulation and optimization of the constructive and technological parameters for magnetosensitive transistors, integrated Hall elements based on the standard CMOS technology, the Hall field sensor based on SOI-structures, and the characteristics of magnetic field concentrators are presented.
Development of magnetic semiconductor microsystems technology
Resumo
The results of the development of technologies of magnetic semiconductor chips based on thinfilm magnetoresistive multilayer structures are presented. A brief overview of the main achievements in the field of magnetometric devices based on anisotropic and giant magnetoresistive effects is made.
Implementation of fast high-order digital filters based on new-generation FPGAs
Resumo
Creation of a multichannel block of the 32nd-order bandpass recursive digital filters with a sampling frequency of 48 MHz is considered. Block diagrams of the unit and its component parts are presented. The detailed description of operation of the unit is given.