High Sensitivity Dual-Gate Four-Terminal Magnetic Sensor Compatible with SOI FinFET Technology

This letter presents a unique device concept of split-current magnetic sensor that is fully compatible with SOI FinFET technology. The fabricated dual-gate four-terminal device brings a step change in SOI integrated sensor capabilities, its measured current related relative sensitivity is as high as 3400 % T-1 at 2 μA of total supply current, comparing to the sensitivity of 3%T-1 exhibited by commercially available silicon MagFETSs. The device’s very high sensitivity is attributed to its novel current conduction phenomena and the internal magnetic deflection enhancement loop demonstrated using 3D TCAD numerical simulations. This new magnetic sensor is a very promising candidate for the next generation of magnetic sensitive smart-power integrated circuits

Transport simulations of ZnO nanowires and semiconductor devices in the presence of scanning probes.

A simulation methodology to model contact and non-contact microscopy measurements has been developed within a 3-D finite element commercial device simulator by Silvaco. The tip-sample system is modelled self-consistently including tip-induced band bending and realistic tip shapes. When modelling scanning tunnelling microscopy, the resulting spectra from III-V semiconductors show good agreement with experimental results and a model based on the Bardeen tunnelling approach. We have found that the image force induced barrier lowering increases the tunnelling current by three orders of magnitude when tunnelling in to the sample valence band, and by six orders of magnitude when tunnelling in to the sample conduction band. We have shown that other models which use a single weighting factor to account for image force in the conduction and valence bands are likely to underestimate the valence band current by three orders of magnitude. The role of probe shank oxide formed at the tip in air has been examined by carrying out contact and non-contact current-voltage simulations of GaAs when the probe oxide has been controllably reduced. For both contact and non-contact simulations, the contact resistance change due to oxide is dependent on polarity and as confirmed experimentally. An electrostatic tip apex interaction with an In203 thin film transistor under operation is studied using a combination of experimental electrostatic force microscopy measurements and simulations. An error in the surface potential near the drain electrode is observed in simulations due to the tip induced band bending. Two point probe measurements on ZnO nanowires and 3-D transport simulations reveal the change in the electrical behaviour of nanoscale contacts from Schottky-like to Ohmic-like when the size of Au catalyst particles is changed at the ends of free-standing ZnO nanowires in relation to the nanowire cross-section. In addition, a geometry dependent current crowding effect was analysed in the combination with self-heating calculations. Finally, we have investigated carrier confinement at the ZnO/GaZnO interface due to band offset and polarization effects. We have found that this material system is a good candidate for polarization heterostructure field effect transistors

The effects of surface stripping ZnO nanorods with argon bombardment

ZnO nanorods are used in devices including field effects transistors, piezoelectric transducers, optoelectronics and gas sensors. However, for efficient and reproducible device operation and contact behaviour, surface contaminants must be removed or controlled. Here we use low doses of argon bombardment to remove surface contamination and make reproducible lower resistance contacts. Higher doses strip the surface of the nanorods allowing intrinsic surface measurements through a cross section of the material. Photoluminescence finds that the defect distribution is higher at the near-surface, falling away in to the bulk. Contacts to the n-type defect-rich surface are near-Ohmic, whereas stripping away the surface layers allows more rectifying Schottky contacts to be formed. The ability to select the contact type to ZnO nanorods offers a new way to customize device behaviour

Способы увеличения точности линейных преобразователей с обратной связью

Наведено схему лінійного перетворювача зі зворотним зв’язком. В статті запропоновано схему лінійного перетворювача змінної напруги з використанням термоперетворювачів та наведено два способи підвищення точності шляхом взаємозаміщення прямого і зворотного перетворювачів, наведено аналітичні вирази для вихідних сигналів, а також відповідні аналітичні вирази похибок.The schematic of a linear transducer with a back coupling is given. The schematic of a linear AC voltage transducer with the use of thermal transducers is given in the article. Two methods for output signal determination were considered, analytical equations for output signal determination and inherent equations for errors determination are given.Приведена схема линейного преобразования с обратной связью. В статье предложена схема линейного преобразования переменного напряжения с использованием термопреобразователей и приведены два способа для определения выходного сигнала, приведены аналитические выражения для выходных сигналов, а также соответствующие аналитические выражения погрешностей

Nondestructive Method for Mapping Metal Contact Diffusion in In2O3 Thin-Film Transistors

The channel width-to-length ratio is an important transistor parameter for integrated circuit design. Contact diffusion into the channel during fabrication or operation alters the channel width and this important parameter. A novel methodology combining atomic force microscopy and scanning Kelvin probe microscopy (SKPM) with self-consistent modeling is developed for the nondestructive detection of contact diffusion on active devices. Scans of the surface potential are modeled using physically based Technology Computer Aided Design (TCAD) simulations when the transistor terminals are grounded and under biased conditions. The simulations also incorporate the tip geometry to investigate its effect on the measurements due to electrostatic tip–sample interactions. The method is particularly useful for semiconductor– and metal–semiconductor interfaces where the potential contrast resulting from dopant diffusion is below that usually detectable with scanning probe microscopy

Potentiometric parameterization of dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene field-effect transistors with a varying degree of non-idealities

Organic transistors with different structures are investigated to address the applicability and reliability of parameter extraction. A dinaphtho[2,3‐b:2′,3′‐f]thieno[3,2‐b]thiophene channel is coupled with pristine or functionalized gold bottom and top contacts to reveal a geometrical impact on the device performance and nonidealities. Scanning Kelvin probe microscopy is employed as a key method to quantify the channel and contact potential in operation. Taking full account of the contact effects and including an explicit threshold voltage in calculation are shown to be critical to access the intrinsic carrier mobility, while simple derivative‐based extraction may over‐ or underestimate it. Further analytical developments correlate individual physical parameters, leading to the discovery that pentafluorobenzenethiol self‐assembled on gold predominantly affects the carrier mobility rather than the injection barrier

Space Charge at Nanoscale: Probing Injection and Dynamic Phenomena Under Dark/Light Configurations by Using KPFM and C-AFM

International audienc

The precision measurements of ac voltage in wide frequency range

В приведеній статті досліджено характеристики існуючих на даний час в світі вимірювачів напруги змінного струму. З урахуванням недоліків існуючих пристроїв запропоновано структурну схему більш точного та більш широкополосного вимірювача.В приведенной статье исследованы характеристики существующих на данное время в мире измерителей напряжения переменного тока. С учетом недостатков существующих устройств предложена структурная схема более точного и более широкополосного измерителя.Characteristics of the existing precision AC voltage instruments are given in the following article. Considering all shortcomings of existing devices the structure chart of the new more accurate and higher bandwidth device is given in the article

The effects of surface stripping ZnO nanorods with argon bombardment

Abstract ZnO nanorods are used in devices including field effects transistors, piezoelectric transducers, optoelectronics and gas sensors. However, for efficient and reproducible device operation and contact behaviour, surface contaminants must be removed or controlled. Here we use low doses of argon bombardment to remove surface contamination and make reproducible lower resistance contacts. Higher doses strip the surface of the nanorods allowing intrinsic surface measurements through a cross section of the material. Photoluminescence finds that the defect distribution is higher at the near-surface, falling away in to the bulk. Contacts to the n-type defect-rich surface are near-Ohmic, whereas stripping away the surface layers allows more rectifying Schottky contacts to be formed. The ability to select the contact type to ZnO nanorods offers a new way to customize device behaviour. S Online supplementary data available from stacks.iop.org/NANO/26/415701/mmedi

The analysis of characteristics and parameters of thermal convertor

В приведеній статті досліджено параметри характеристик термоперетворювачів типу ТВБ, ДТПТ та ДТПС. Досліджена нестабільність у часі, зокрема п’ятихвилинна нестабільність. Запропонована модель перехідних процесів диференційних термоперетворювачів. Наведені результати експериментальних досліджень. Зроблено порівняння похибок нестабільності різних термоперетворювачів.В приведенной статье исследованы параметры характеристик термопреобразователей типа ТВБ, ДТПТ и ДТПС. Исследована нестабильность во времени, в частности пятиминутная нестабильность. Предложена модель переходных процессов дифференциальных термопреобразователей. Приведены результаты экспериментальных исследований. Сделано сравнение погрешностей нестабильности разных термопреобразователей.In the article parameters and characteristics for thermal convertors type ТВБ, ДТПТ and ДТПС were described. Investigation of the time instability took place, in particular the 5 minutes instability. The model of transient process for differential thermal convertors was proposed. Experimental research data is given. The comparison of instability errors for different convertors was made