2015 International Conference on Noise and Fluctuations (ICNF), 2015
We present results of a comprehensive study of the liquid-back gate coupling effect in our Si nan... more We present results of a comprehensive study of the liquid-back gate coupling effect in our Si nanowire (NW) field-effect transistor (FET) structures using noise spectroscopy in different operation modes, including variable back-gate voltage. The constant channel resistance regime was used for measurements of the transport and noise properties of the liquid-gated Si NW FETs and simulations using Sentaurus TCAD software to improve our understanding of the coupling effect phenomena. The concentration profiles were simulated for different liquid- and back-gate voltages, which correspond to the experimental working points. The noise spectra were studied while tuning the position of the conducting channel in the liquid-gated Si NW FET. Results demonstrate that the dominant flicker noise mechanism in such structures is the number fluctuations due to the localization of the conducting channel near the dielectric layer of the liquid gate.
The transport and noise properties of fabricated, high‐performance, gate‐all‐around silicon liqui... more The transport and noise properties of fabricated, high‐performance, gate‐all‐around silicon liquid‐gated nanowire field‐effect transistor devices are investigated in different concentrations of MgCl2 solutions. The critical concentration of MgCl2 solution for charge inversion at the solid‐liquid interface is verified using noise spectroscopy and confirmed using the capacitance‐voltage measurement technique. In this study, it is found that the Hooge parameter (αH) and the equivalent input noise (SU) can effectively reflect the ion behavior on the surface of the nanowire. Moreover, the noise curves for αH and SU indicate two turning points at concentrations of 10−4 and 10−1 m for a peak and a valley, respectively. The noise transformation is related to the behavior of ions near the solid‐liquid interface in solutions with different MgCl2 concentrations is revealed. The results show that noise spectroscopy is a powerful method for monitoring charge dynamic processes in the research fie...
У данiй роботi представлено результати дослiдження електричних властивостей плiвок нових тернарни... more У данiй роботi представлено результати дослiдження електричних властивостей плiвок нових тернарних нанокомпозитiв дiелектричного полiмеру полiвiнiлiденфториду (ПВДФ), провiдного полiмеру полiанiлiну, допованого додецилбензолсульфоновою кислотою (ПАНI), з рiзним вмiстом мультистiнних вуглецевих нанотрубок (МСВНТ). На основi результатiв дослiджень електричного опору нанокомпозитiв у широкому iнтервалi температур 4,2–300 К показано, що при низьких температурах для нанокомпозитiв iз вмiстом МСВНТ 0–15 мас.% перенесення електричних зарядiв вiдбувається за рахунок тунелювання носiїв заряду мiж локалiзованими станами вiдповiдно до механiзму стрибкової провiдностi зi змiнною довжиною стрибка R ∼ exp[(T0/T)1/2]. Встановлено, що величина характеристичної температури T0 i температурний iнтервал стрибкової провiдностi залежать вiд вмiсту МСВНТ. Збiльшення вмiсту МВСНТ у плiвках нанокомпозитiв вiд 0–15 мас.% приводить до зменшення характеристичної температури T0 на два порядки i звуження темпера...
The influence of the cyclic heating and cooling on properties of the aggregates (aka "ferrof... more The influence of the cyclic heating and cooling on properties of the aggregates (aka "ferrofluid clusters") in a ferrofluid, which made on the basis of magnetite nanoparticles, are investigated. The heating of the ferrofluid layer with such aggregates leads to equalization of the concentration between high- and low-concentrated phases. The temperature of the equalization of the phase concentrations was determined at different values of an external constant magnetic field, which was applied parallel to the layer of the ferrofluid. The temperature of the destruction of a periodic structure of the magnetic aggregates, which were formed during cooling of a homogeneous phase of the ferrofluid, was obtained at the different values of the applied external magnetic field.
Proceedings of the IEEE 21st International Conference on Noise and Fluctuations, ICNF 2011, 2011
ABSTRACT We report results of noise spectroscopy of field-effect transistors (FETs) fabricated ba... more ABSTRACT We report results of noise spectroscopy of field-effect transistors (FETs) fabricated based on individual carbon nanotube (CNT) using back-gate topography. The registered noise spectra allow us to estimate the numbers of carriers in working point with maximal transconductance. Lorentzian-shape noise components were analyzed in wide temperature range. The analysis enables us to find the energy, position and concentration of traps in the CNT-FET structures.
International Journal of High Speed Electronics and Systems, 2004
Transport and low frequency noise properties of undoped AlGaN/GaN high electron mobility transist... more Transport and low frequency noise properties of undoped AlGaN/GaN high electron mobility transistor (HEMT) heterostructures with 33% and 75% Al mole fractions in the ohmic and non-linear regimes of applied voltages are studied. In contrast to the low Al mole fraction, the noise properties of 75 % content structures are not affected by passivation. At small voltages both kinds of structures demonstrate about the same level of l/f excess noise. Deviations from conventional flicker noise were observed at high applied voltages. Additionally, differences in noise behaviour between the two structures were revealed. In the 75% content structures, a noise level suppression was registered in the non-linear regime, which is important for the development of low noise oscillator circuits.
2017 International Conference on Noise and Fluctuations (ICNF), 2017
GaN-based nanoribbons (NRs) represent important structures because of their unique transport prop... more GaN-based nanoribbons (NRs) represent important structures because of their unique transport properties. They have high breakdown voltage and can be scaled down to nanosizes. We studied the transport and noise properties of NRs in a wide temperature range applying different external treatments: ultraviolet (UV) excitation and high voltage bias. Characteristic features in the form of bumps were revealed in the temperature dependences of conductivity. The effect becomes more pronounced with decreasing NR width. Such exceptional behavior is related to a contribution of depletion regions at the edges of the NR to the sample conductivity. Characteristic energies of the deep traps in NR structures were obtained using generation-recombination components of measured noise spectra. Noise spectroscopy provides information about dynamic processes in structures. Depletion effects in AlGaN/GaN nanoribbons can be controlled using external UV excitation and applied electric fields. The results are...
Junctionless p+-p-p+ silicon nanowire (NW) field-effect transistors with various geometries were ... more Junctionless p+-p-p+ silicon nanowire (NW) field-effect transistors with various geometries were fabricated. Noise measurements were performed for the samples with different widths and in different operation modes. Results demonstrate significant changes in noise and Hooge parameter when the NW geometry is changed. The dependences obtained can be explained by considering the different impacts of the top and two side silicon oxide interfaces formed on the nanowire walls. According to the fabrication process, where anisotropic wet etching was used, almost atomic flat side wall surfaces make a smaller contribution to the noise compared to top walls in NWs of different widths. This effect results in a decreased noise level in NW FETs of smaller NW widths, operating in a weak accumulation regime. The effects thus revealed are important for improving the signal-to-noise ratio in liquid-gated biosensors.
In this work we present steady-state characteristics and low-frequency noise spectra of AlGaN/GaN... more In this work we present steady-state characteristics and low-frequency noise spectra of AlGaN/GaN based high electron mobility transistors (HEMTs) exposed to gamma ray radiation. The devices with a variety of gate length (150-350 nm) and width (100-400 νm) were irradiated by 60Co gamma rays with doses in the range of 104-109 Rad and flux of 102 Rad/s. Dose dependencies of basic operating parameters of the transistors, such as saturation current (Isat), transconductance (gm), channel conductance (gc), and threshold voltage (VT) are analysed. Our study show that visible changes of above mentioned parameters are observed under relatively small doses (105 Rad) and strongly depend on the HEMT's topology. The transconductance decreases and threshold voltage becomes more negative for all devices while deviation of these parameters from its initial values does not exceed 20% at highest irradiation dose. At the same time variation of the channel conductance as well as saturation current ...
International Semiconductor Device Research Symposium, 2003
In this paper, we presented results of steady state and pulse measurement of AlGaN/GaN heterostru... more In this paper, we presented results of steady state and pulse measurement of AlGaN/GaN heterostructures up to ultra high electric fields accompanied by low frequency noise measurements. Hot electron relaxation process were analysed. The contact resistance was measured in low field (ohmic) region and taken into account when calculating the average electric field. The velocity-field characteristics in AlGaN/GaN heterostructures obtained by measurement of the current-voltage characteristics. The spectra of the normalised current noise for different values of electric field E measured at T=300 K for the device with channel length of 25 μm and width of 100 μm is studied through experimental results.
2015 International Conference on Noise and Fluctuations (ICNF), 2015
We present results of a comprehensive study of the liquid-back gate coupling effect in our Si nan... more We present results of a comprehensive study of the liquid-back gate coupling effect in our Si nanowire (NW) field-effect transistor (FET) structures using noise spectroscopy in different operation modes, including variable back-gate voltage. The constant channel resistance regime was used for measurements of the transport and noise properties of the liquid-gated Si NW FETs and simulations using Sentaurus TCAD software to improve our understanding of the coupling effect phenomena. The concentration profiles were simulated for different liquid- and back-gate voltages, which correspond to the experimental working points. The noise spectra were studied while tuning the position of the conducting channel in the liquid-gated Si NW FET. Results demonstrate that the dominant flicker noise mechanism in such structures is the number fluctuations due to the localization of the conducting channel near the dielectric layer of the liquid gate.
The transport and noise properties of fabricated, high‐performance, gate‐all‐around silicon liqui... more The transport and noise properties of fabricated, high‐performance, gate‐all‐around silicon liquid‐gated nanowire field‐effect transistor devices are investigated in different concentrations of MgCl2 solutions. The critical concentration of MgCl2 solution for charge inversion at the solid‐liquid interface is verified using noise spectroscopy and confirmed using the capacitance‐voltage measurement technique. In this study, it is found that the Hooge parameter (αH) and the equivalent input noise (SU) can effectively reflect the ion behavior on the surface of the nanowire. Moreover, the noise curves for αH and SU indicate two turning points at concentrations of 10−4 and 10−1 m for a peak and a valley, respectively. The noise transformation is related to the behavior of ions near the solid‐liquid interface in solutions with different MgCl2 concentrations is revealed. The results show that noise spectroscopy is a powerful method for monitoring charge dynamic processes in the research fie...
У данiй роботi представлено результати дослiдження електричних властивостей плiвок нових тернарни... more У данiй роботi представлено результати дослiдження електричних властивостей плiвок нових тернарних нанокомпозитiв дiелектричного полiмеру полiвiнiлiденфториду (ПВДФ), провiдного полiмеру полiанiлiну, допованого додецилбензолсульфоновою кислотою (ПАНI), з рiзним вмiстом мультистiнних вуглецевих нанотрубок (МСВНТ). На основi результатiв дослiджень електричного опору нанокомпозитiв у широкому iнтервалi температур 4,2–300 К показано, що при низьких температурах для нанокомпозитiв iз вмiстом МСВНТ 0–15 мас.% перенесення електричних зарядiв вiдбувається за рахунок тунелювання носiїв заряду мiж локалiзованими станами вiдповiдно до механiзму стрибкової провiдностi зi змiнною довжиною стрибка R ∼ exp[(T0/T)1/2]. Встановлено, що величина характеристичної температури T0 i температурний iнтервал стрибкової провiдностi залежать вiд вмiсту МСВНТ. Збiльшення вмiсту МВСНТ у плiвках нанокомпозитiв вiд 0–15 мас.% приводить до зменшення характеристичної температури T0 на два порядки i звуження темпера...
The influence of the cyclic heating and cooling on properties of the aggregates (aka "ferrof... more The influence of the cyclic heating and cooling on properties of the aggregates (aka "ferrofluid clusters") in a ferrofluid, which made on the basis of magnetite nanoparticles, are investigated. The heating of the ferrofluid layer with such aggregates leads to equalization of the concentration between high- and low-concentrated phases. The temperature of the equalization of the phase concentrations was determined at different values of an external constant magnetic field, which was applied parallel to the layer of the ferrofluid. The temperature of the destruction of a periodic structure of the magnetic aggregates, which were formed during cooling of a homogeneous phase of the ferrofluid, was obtained at the different values of the applied external magnetic field.
Proceedings of the IEEE 21st International Conference on Noise and Fluctuations, ICNF 2011, 2011
ABSTRACT We report results of noise spectroscopy of field-effect transistors (FETs) fabricated ba... more ABSTRACT We report results of noise spectroscopy of field-effect transistors (FETs) fabricated based on individual carbon nanotube (CNT) using back-gate topography. The registered noise spectra allow us to estimate the numbers of carriers in working point with maximal transconductance. Lorentzian-shape noise components were analyzed in wide temperature range. The analysis enables us to find the energy, position and concentration of traps in the CNT-FET structures.
International Journal of High Speed Electronics and Systems, 2004
Transport and low frequency noise properties of undoped AlGaN/GaN high electron mobility transist... more Transport and low frequency noise properties of undoped AlGaN/GaN high electron mobility transistor (HEMT) heterostructures with 33% and 75% Al mole fractions in the ohmic and non-linear regimes of applied voltages are studied. In contrast to the low Al mole fraction, the noise properties of 75 % content structures are not affected by passivation. At small voltages both kinds of structures demonstrate about the same level of l/f excess noise. Deviations from conventional flicker noise were observed at high applied voltages. Additionally, differences in noise behaviour between the two structures were revealed. In the 75% content structures, a noise level suppression was registered in the non-linear regime, which is important for the development of low noise oscillator circuits.
2017 International Conference on Noise and Fluctuations (ICNF), 2017
GaN-based nanoribbons (NRs) represent important structures because of their unique transport prop... more GaN-based nanoribbons (NRs) represent important structures because of their unique transport properties. They have high breakdown voltage and can be scaled down to nanosizes. We studied the transport and noise properties of NRs in a wide temperature range applying different external treatments: ultraviolet (UV) excitation and high voltage bias. Characteristic features in the form of bumps were revealed in the temperature dependences of conductivity. The effect becomes more pronounced with decreasing NR width. Such exceptional behavior is related to a contribution of depletion regions at the edges of the NR to the sample conductivity. Characteristic energies of the deep traps in NR structures were obtained using generation-recombination components of measured noise spectra. Noise spectroscopy provides information about dynamic processes in structures. Depletion effects in AlGaN/GaN nanoribbons can be controlled using external UV excitation and applied electric fields. The results are...
Junctionless p+-p-p+ silicon nanowire (NW) field-effect transistors with various geometries were ... more Junctionless p+-p-p+ silicon nanowire (NW) field-effect transistors with various geometries were fabricated. Noise measurements were performed for the samples with different widths and in different operation modes. Results demonstrate significant changes in noise and Hooge parameter when the NW geometry is changed. The dependences obtained can be explained by considering the different impacts of the top and two side silicon oxide interfaces formed on the nanowire walls. According to the fabrication process, where anisotropic wet etching was used, almost atomic flat side wall surfaces make a smaller contribution to the noise compared to top walls in NWs of different widths. This effect results in a decreased noise level in NW FETs of smaller NW widths, operating in a weak accumulation regime. The effects thus revealed are important for improving the signal-to-noise ratio in liquid-gated biosensors.
In this work we present steady-state characteristics and low-frequency noise spectra of AlGaN/GaN... more In this work we present steady-state characteristics and low-frequency noise spectra of AlGaN/GaN based high electron mobility transistors (HEMTs) exposed to gamma ray radiation. The devices with a variety of gate length (150-350 nm) and width (100-400 νm) were irradiated by 60Co gamma rays with doses in the range of 104-109 Rad and flux of 102 Rad/s. Dose dependencies of basic operating parameters of the transistors, such as saturation current (Isat), transconductance (gm), channel conductance (gc), and threshold voltage (VT) are analysed. Our study show that visible changes of above mentioned parameters are observed under relatively small doses (105 Rad) and strongly depend on the HEMT's topology. The transconductance decreases and threshold voltage becomes more negative for all devices while deviation of these parameters from its initial values does not exceed 20% at highest irradiation dose. At the same time variation of the channel conductance as well as saturation current ...
International Semiconductor Device Research Symposium, 2003
In this paper, we presented results of steady state and pulse measurement of AlGaN/GaN heterostru... more In this paper, we presented results of steady state and pulse measurement of AlGaN/GaN heterostructures up to ultra high electric fields accompanied by low frequency noise measurements. Hot electron relaxation process were analysed. The contact resistance was measured in low field (ohmic) region and taken into account when calculating the average electric field. The velocity-field characteristics in AlGaN/GaN heterostructures obtained by measurement of the current-voltage characteristics. The spectra of the normalised current noise for different values of electric field E measured at T=300 K for the device with channel length of 25 μm and width of 100 μm is studied through experimental results.
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Papers by Mykhaylo Petrychuk