Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine 8 PACS 85

Abstract. We consider the features of formation of AuTiPd ohmic contacts to p + -Si. Metallization was made by vacuum thermal sputtering of Pd, Ti and Au films onto the Si substrate heated up to 330 С. It is shown that the contact resistivity increases with temperature; this is typical of metallic conductivity. We suggest that the ohmic contact is formed owing to appearance of shunts at Pd deposition on dislocations or other structural defects. The number of shunts per unit area is close to the measured density of structural defects at the metalSi interface

БІОХІМІЧНІ СЕНСОРНІ СИСТЕМИ НА ОСНОВІ ПОРИСТИХ ПЛІВОК ОКСИДУ АЛЮМІНІЮ З НАНОЧАСТКАМИ ЗОЛОТА В УМОВАХ ПОВНОГО ВНУТРІШНЬОГО ВІДБИТТЯ

The possibility of the development of the biochemical sensor systems on the base of the films with the controlled level of the spectral selective absorption under the total internal reflection (TIR) conditions. It was demonstrated that porous Al2 O3 films with the Au nanoparticles obtained by the impulse laser deposition are characterize by the presence of the minimum at the angle dependence of the reflectance factor under TIR conditions. The optical model of the sensor system in the limits of the macroscopic Maxwell theory. The effectiveness of the use of introduced transducers was demonstrated on the case of the refractometric measurements and the monitoring of the protein-protein interactions.Рассмотрена возможность разработки биохимических сенсорных систем на основе пленок с контролируемым уровнем спектрально селективного поглощения в условиях полного внутреннего отражения (ПВО). Показано, что пористые пленки Al2 O3 с наночастицами Au, полученные импульсным лазерным осаждением, характеризуются наличием минимума на угловой зависимости коэффициента отражения в условиях ПВО. Проанализирована оптическая модель сенсорной системы в рамках макроскопической теории Максвелла. Эффективность использования предложенных преобразователей в качестве оптоэлектронных сенсорных элементов продемонстрирована на примере рефрактометрических измерений и мониторинга белок-белковых взаимодействий.Розглянуто можливість розробки біохімічних сенсорних систем на основі плівок з контрольованим рівнем спектрально селективного поглинання в умовах повного внутрішнього відбиття (ПВВ). Показано, що пористі плівки Al2 O3 з наночастками Au, отримані імпульсним лазерним осадженням, характеризуються наявністю мінімума на кутовій залежності коефіцієнту відбиття в умовах ПВВ. Проаналізовано оптичну модель сенсорної системи в рамках макроскопічної теорії Максвела. Ефективність використання запропонованих перетворювачів як оптоелектронних сенсорних елементів продемонстрована на прикладі рефрактометричних вимірів і моніторингу білок-білкових взаємодій

Forming of 4НSiC p–i–n-diodes mesastructures by the ion-plasmous etching method

The results of research and optimization of 4НSiC p–i–n-diodes mesastructures manufacturing method are presented as well as analysis of current-voltage characteristics and switching characteristics of p–i–n-diodes in the 25—500°C temperature range

Effect of external actions on characteristics of gallium arsenide Schottky-barrier diode structures

In this paper we analyze briefly literary information about an effect of external actions on electrophysical characteristics of gallium arsenide Schottky-barrier diode structures and their stability to external influences. We discussed radiation changes of gallium arsenide Schottky-barrier diode structures, and also we discuss effects of small radiation dose treatment

Features of temperature dependence of contact resistivity in ohmic contacts on lapped n-Si

The temperature dependence of contact resistivity rho(c) in lapped silicon specimens with donor concentrations of 5 x 10(16), 3 x 10(17), and 8 x 10(17) cm(-3) was studied experimentally. We found that, after decreasing part of the rho(c)(T) curve in the low temperature range, an increasing part is registered with increasing temperature T. It is demonstrated that the formation of contact to a lapped Si wafer results in the generation of high dislocation density in the near-surface region of the semiconductor and also in ohmic contact behavior. In this case, current flows through the metal shunts associated with dislocations. The theory developed is in good agreement with experimental results. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4752715

Terahertz self-induced oscillations in the injection p-n junction with fixed reverse bias

The results of numerical solutions of the complete equations of the diffusion-drift model (DDM) of Ge, Si and GaAs reverse-biased abrupt p–n junctions with injection of the constant-intensity electron flow into the p–region have been presented. The excitation mechanism of p–n junctions was examined and the factors affecting the frequency and amplitude of self-induced oscillations were established. The spectra of power and electron efficiency have been also presented. Abrupt Ge, Si and GaAs p–n junctions were shown to generate oscillations over the entire microwave range, while the second harmonic frequency could reach the terahertz (THz) range