Peter Benko

Electrical Properties of Recessed Algan/Gan Schottky Diodes Under off–State Stress

Abstract Electrical properties of recessed and non-recessed AlGaN/GaN Schottky diodes under off-state stress were investigated. The samples were consecutively stressed by the stepped negative bias (−60 V). Before and after the stress I−V and C−V characteristics were evaluated to verify the device degradation process. Finally, the degradation mechanism and the influence of AlGaN recessed layer thickness on the electrical properties of the Schottky diodes were analysed. It was found that the short time stress influence on I−V characteristics was most negligible for the non-recessed sample. Shallow and deep recessed samples exhibited initial trap filling and reverse current decrease. Generally it was found that the stress voltage near 60 V caused recoverable device degradation

Massive open online courses in microelectronics education

A massive open online course (MOOC) is a model for delivering learning content online with no limit on attendance to any person who expresses interest. This paper highlights the challenges, advantages and rewards of the MOOC model in microelectronics education. The authors are focusing on the practical experiences acquired in design and realization of MOOC located on an educational portal called “eLearn central” based on LMS Moodle.

3-D device and circuit electrothermal simulations of power integrated circuit including package

In this paper we present an advanced methodology for effective 3-D device electrothermal simulation of power structures and power integrated circuits. The proposed electrothermal simulation is based on direct interconnection of a 3-D FEM thermal model and electrical circuit model of the device using a mixed-mode setup supported in Synopsys TCAD Sentaurus environment. This approach combines the speed and accuracy, and couples temperature nonuniformity to the active device electrothermal behaviour. The simulation results are compared with circuit electrothermal simulation which uses electrical RC network as an equivalent of the thermal system. The features and limitations of the methods are analyzed and presented.

Coupled Defect Level Recombination in the P—N Junction

Coupled Defect Level Recombination in the P—N Junction The well known Shockley-Read-Hall (SRH) model considers emission and capture processes at defects exhibiting a single level or multiple non-coupled levels in the band gap of the semiconductor. The present paper generalizes the model to the case of two mutually coupled defect levels acting as trapping centres. If the intercenter transition is not considered, the model reduces to the case of two non-coupled levels treated by the SRH model.

How to prepare university graduates as highly skilled key enabling technologies professionals

Key Enabling Technologies represent the background of a greener economy and Europes industrial modernization. High quality preparation of great number of highly skilled Key Enabling Technologies professionals is essential for the future economic growth, competitiveness and innovation of Europe. This article presents experiences acquired by long term involvement of the Institute of Electronics and Photonics, Slovak University of Technology in Bratislava, in training Key Enabling Technologies professionals. Authors focused their attention on selected examples of available effective tools to prepare highly skilled university graduates.

Through ICT and new pedagogical approaches to skills for key enabling technologies

This article deals with the issue of Key Enabling Technologies (KETs), representing a basis for innovative approaches shifting to a greener economy and Europes industrial modernisation. Requirements to prepare university graduates as highly skilled KETs professionals, is are becoming more and more important. Facing this challenge authors see the solution in effective application of ICT and new pedagogical approaches.

Model of Coupled Defect Level Recombination with Participation of Multiphonons

We present a new model of two coupled defect-level recombination. Calculation of the generation and recombination rates is based on the so-called exchange times. These allow calculating the occupation probability of the trapping centres and subsequently the generation-recombination rates of free charge carriers appearing in the continuity equations. Each of these two coupled defect levels has its specific trap density, position in the forbidden band and capture cross-section obtained from DLTS measurements.

Degradation processes in AlGaN/GaN HEMTs under high drain-bias off-state stress

This paper reports on degradation processes in the AlGaN/GaN HEMTs under high drain-bias off-state stress. The devices were off-stressed at the drain voltage of 60 V and the gate voltage of -5 V for 30 min, resp.60 min. Static device performance was evaluated before, during and after the stress. Performed measurements show a slight degradation in the drain current and a decrease of the threshold voltage. However, these effects are partially recovered as follows from the measurement performed 30 min after the stress. All these indicates that the electrons that accumulate in the structure as well as on the surface of AlGaN layer create an electrostatic charge induced by high electric field between gate and drain. This causes a reduction in the channel current and plays a major role during the off-state degradation of AlGaN/GaN HEMTs.

DLTS study of electrically active defects in triple quantum well InGaAsN/GaAs heterostructures

Deep Level Transient Fourier Spectroscopy study of charge carrier emission from quantum wells and electrically active defects in triple quantum well InGaAsN/GaAs heterostructures is discussed. Main attention is focused on the comparison and evaluation of measured spectra and to state the conditions of quantum well charge carrier emission identification. The presence of several deep energy levels and their parameters typical for GaAs are reported.

Power MOSFET interactive e-learning course

This paper shows authors motivation and experience in design and realization of interactive e-learning course “Power MOSFET”. The course deals with the basic theory of power electronic devices, working principles, advantages, disadvantages, new trends and with practical results obtained from measurements and 3-D TCAD simulations in this course. Aim of course is to assure the rise of education efficiency and help students to reduce knowledge differences. This e-learning project will be accessible on the educational portal “eLearn central”. This portal uses learning environment Moodle.