Modelling electroforming process under constant bias voltage conditions

In order to understand changes in defect concentration during the electroforming process, we modelled the electroforming process in Ta/HfO2/Pt under constant bias voltage. For this purpose, kinetic Monte-Carlo and finite element methods were utilized. Vacancy profiles were obtained for forming voltages from 3 V to 5 V; modelling of lower stresses is time-consuming. It was found that with decreasing voltage, vacancies begin to accumulate near the inert electrode. When the voltage was dropped from 5 to 3 V, the thickness of such a layer increased by 1 nm, and electroforming time exponentially increase.

Исследование плотности интерфейсных состояний на границах раздела диэлектрик / In-=SUB=-0.52-=/SUB=-Al-=SUB=-0.48-=/SUB=-As

The capacitance-voltage (С-V) characteristics of Au/Al2O3/In0.52Al0.48As and Au/SiO2/In0.52Al0.48As metal-insulator-semiconductor (MIS) structures were studied. It was found that the measurement of the C-V characteristics of MIS structures based on InAlAs by the fragment method, in contrast to the standard technique at a constant bias voltage scan rate, significantly reduces the hysteresis effect and allows to obtain stationary curves. It was shown that the fast interface states density calculated by the Terman method from such C-V characteristics varies slightly along the InAlAs band gap and amounts to (3-6) 1011 eV-1cm-2 and (1-3)·1011 eV-1cm-2 for MIS structures with Al2O3 and SiO2, respectively.

Spectacular oscillations in the dark and photocurrent in thiol-capped CdS quantum dots embedded in PMMA matrix

Oscillatory behaviour of current in thiol-capped CdS QDs embedded PMMA matrix under dark conditions at different sample cell temperatures: (1) 303, (2) 308, (3) 313, (4) 318, (5) 323 and (6) 328 K with a constant bias voltage of 27 V.

NOISE PROPERTIES OF HIGH TEMPERATURE SUPERCONDUCTING BOLOMETERS

The review describes the noise properties of the high temperature superconducting (HTS) bolometers developed for the applications in the optical electronic devices of infrared and submillimeter wave-lengths. The principle of high-Tc transition edge bolometer operation and bolometer noise theory are considered, taking into account the peculiarities of constant bias current and constant bias voltage modes. The published results of bolometer noise modeling are discussed. Various sources of the excess 1/f-noise in HTS films as temperature sensitive element for bolometer are reviewed, including the experimental data and modern noise models. Comparative analysis of noise characteristics of the most developed HTS bolometers for application (antenna-coupled microbolometers and bolometers based on silicon micromachining technology) is reported.