Presented here is a patent in the Bulgarian register of inventions (Reg. № 27611/1974), written in Bulgarian. The patent relates to novel types of leads for various semiconductor devices: integrated circuits, photodiodes, modular packaged discrete devices, etc. The new leads configuration is proposed in order to avoid some of the disadvantages of the existing ones. Illustrated are several examples of assemblies demonstrating the advantages and the versatility of packaging methods applying this novel leads configuration.

The invention described features two claims. The description is supported by five drawings.

A method is investigated to directly engineer the voltage swing in SiGe resonant interband tunnel diodes (RITDs). Voltage swing, defined here as the voltage difference between the peak voltage and the projected peak voltage, is independent of series resistance, and thus directly impacts the noise margin in hybrid tunnel diode memory and logic applications. The three components of the total RITD current are analyzed to describe the voltage swing. The dependence of voltage swing on -doping concentrations and post-growth annealing temperatures in SiGe RITDs grown by low-temperature molecular beam epitaxy (LT-MBE) is investigated and the experimental results are compared with a theoretical analysis. Techniques to increase the voltage swing are discussed.

Hysteresis behaviour of the current–voltage characteristics collected on spin coated synthetic eumelanin layer embedded in the Au/eumelanin/ITO/glass structure is shown. The effect has been observed under dark both in air and vacuum environment and its magnitude has been found related to the eumelanin hydration state. Moreover, in vacuum and under white light illumination, enhancement of the hysteresis loop area respect to those collected under dark has been observed. Space charge storage and charge trapping/detrapping as possible mechanisms responsible of the observed current–voltage behaviour are discussed. Preliminary experimental results have evidenced the possible integration of eumelanin layers in electro-optical charge storage based memory devices.

The electron and hole mobility of Si complementary metal on oxide field effect transistors (CMOS) can be enhanced by introducing a biaxial tensile stress in the Si channel. This paper outlines several key analytical techniques needed to investigate such layers. Raman scattering is used to measure the strain in the Si channel as well as to map the spatial distribution of strain in Si at a lateral resolution better than 0.5 μm. Atomic force microscopy (AFM) is used to measure the surface roughness. Transmission electron microscopy (TEM) is used to reveal dislocations in the structure, the nature of the dislocations and the propagation of the dislocations. Secondary ion mass spectrometry (SIMS) is used to monitor the Ge content profile in the structure and the thickness of each layer. In the long term, inline nondestructive techniques are desired for epi-monitoring in manufacturing. Two techniques, spectroscopic ellipsometry (SE) and x-ray reflectivity (XRR), have shown promise at this stage.

We investigated bulk and thin-film samples of the quaternary p-type semiconductor Cu2ZnSnS4 (CZTS) by µSR, in order to characterize the existing muonium signals. We find that the majority of the implanted muons form a diamagnetic state broadened by an interaction with the Cu nuclear moments, which we interpret as Mu + bound to sulphur. A paramagnetic fraction is also present at low temperatures and the ratio between the two muon charge states, Mu + and Mu 0 , varies between 20 and 40% prior to the onset of muon diffusion, which occurs at around 150 K. The fraction of Mu 0 is found to be sensitive to the defect content of the sample. The paramagnetic fraction has two different contributions and their origin is discussed and related with the muon role as a probe for charge carriers in the material.

This research is motivated by issues faced by a large manufacturer of semiconductor devices. Semiconductor manufacturing companies allocate millions of dollars every year for new types of machine tools for their facilities. Typically these are special purpose machine tools which are made to order. The rate of change in products and technology makes it diÅcult for manufacturers to have a

This study investigated the relationship between the self-efficacy of basic school headteachers in Effutu municipality and their leadership effectiveness. The purpose of the study was to determine whether the selfefficacy of Basic School Heads in Effutu Municipality affects their leadership effectiveness. The quantitative method was used for the study. A population of 85 headteachers and 145 teachers were drawn from the 85 basic schools in Effutu municipality via total/whole enumeration and random sampling techniques respectively. The structured questionnaires were used to collect the data. The quantitative survey data was analysed with SPSS, specifically, frequencies and correlation. One research question and two hypotheses were formulated to guide the study. The major finding of the study was that the basic school headteachers self-efficacy affects their leadership effectiveness and that there is a positive relationship between self-efficacy and leadership effectiveness. G.E.S. should consider the self-efficacy of teachers before selecting them as heads for Basic Schools for effective academic performance or should invest in stimulating the self-efficacy of heads so as to work effectively. Other organizations should consider building the self-efficacy of their leadership so as to improve their effectiveness in performing their duties and also, rate selfefficacy high on recruitment requirements of applicants at recruitment interviews.

This paper presents the selection process of the best suited topology for a bidirectional charger, intended to be economically implemented for a small electric vehicle with a 16 kWh battery package. The first stage is a State-of-the-Art revision, whose results are a reduced number of topologies pre-selected. Second stage is the evaluation through Multisim-NI Simulation of the pre-selected topologies; looking for the better relation: number of semiconductor devices, stresses to which semiconductor devices are subjected, number of control signals needed with its associated measurement devices, passive elements size and total losses.

The lithography is a basic operation in the fabrication process of semiconductor devices. The scaling ability is the reason why the atomic force microscopy (AFM) nanolithograpy is currently studied in many laboratories. In the paper, the results of the mechanical AFM lithography, named nanoscribing or nanoscratching, are presented. In this method, the pattern is created by mechanical interaction between the AFM tip and a sample. This interaction requires the application of large forces in micronewtons scale.

This paper presents an integrated stimulator that can be embedded in implantable electrode books for interfacing with nerve roots at the cauda equina. The Active Book overcomes the limitation of conventional nerve root stimulators which can only support a small number of stimulating electrodes due to cable count restriction through the dura. Instead, a distributed stimulation system with many tripole electrodes can be configured using several Active Books which are addressed sequentially.

I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public.

Based on an active transmission line concept and twodimensional (2-D) device simulations, an accurate and computationally efficient simulation technique for high frequency noise performance of MOSFETs is demonstrated. Using a Langevin stochastic source term model and small-signal equivalent circuit of the MOSFET, three intrinsic noise parameters ( , , and ) for the drain noise and induced gate noise are calculated. Validity and error analysis for the simulation are discussed by comparing the simulation results with theoretical results as well as measured data.

The LabVIEW system suitability for a device research laboratory is evaluated in this paper. The system is applied successfully to the study of MOSFET device degradation under low radiation doses with the highly repetitive measurement using the well known charge pumping technique. Radiationinduced threshold voltage shift (ΔV TH ), Radiation-induced flatband voltage shift (ΔV FB ), radiation-induced oxide-trap (ΔN OT ), and radiation-induced interface-trap (ΔN IT ) are extracted. The irradiated MOSFET transistors are characterized with the developed software.

We have designed and built a new type of chemically sensitive semiconductor device based on the operation of a gate-controlled diode. This structure provides both electrical and chemical shielding of the contact regions from the solution. Ions in the solution provide the driving force for the chemically sensitive layer.

We have carried out a detailed experimental investigation of the trap parameters -trap energy, trap density, and hole capture crosssection -in a large number of p-Si/SiO 2 /HfO 2 /TaN MOS capacitors fabricated on wafers with graded SiO 2 layer, and of the flat-band voltage, using a newly developed admittance spectroscopy technique, which yields accurate values of the surface potential and the flat-band voltage, and makes use of the measured conductance to obtain accurate values of the trap parameters. The correlation, if any, between the trap density and the flat-band voltage has been analyzed.

Growing interest in battery performance and cost reduction for hybrid and electric vehicles has restimulated interest in the United States in the use of high-power batteries as a potential source of pulsed power. Recent progress in high-powerdensity lithium-ion batteries and high-power semiconducting switches has suggested that a battery-inductor-based pulsed power system could become a viable option to pulsed alternators for electromagnetic (EM) launchers and other pulsed loads in the megajoule range. Approximate system sizing and a parametric study are presented, showing the effects of battery and inductor parameters on the overall efficiency and system size for a conceptual 2-MJ muzzle energy EM launch system utilizing the STRETCH circuit topology. The results show the relationship between potential increases in future component performance on overall system size reduction and efficiency.

ABSTRACT Silicon carbide (SiC) semiconductor devices for high power applications are now commercially available as discrete devices. Recently Schottky diodes are offered by both USA and Europe based companies. Active switching devices such as bipolar junction transistors (BJTs), field effect transistors (JFETs and MOSFETs) are now available on the commercial market. The interest is rapidly growing for these devices in high power and high temperature applications. The main advantages of wide bandgap semiconductors are their very high critical electric field capability. From a power device perspective the high critical field strength can be used to design switching devices with much lower losses than conventional silicon based devices both for on-state losses and reduced switching losses. This paper reviews the current state of the art in active switching device performance for both SiC and GaN. SiC material quality and epitaxy processes have greatly improved and degradation free 100 mm wafers are readily available. The SiC wafer roadmap looks very favorable as volume production takes off. For GaN materials the main application area is geared towards the lower power rating level up to 1 kV on mostly lateral FET designs. Power module demonstrations are beginning to appear in scientific reports and real applications. A short review is therefore given. Other advantages of SiC is the possibility of high temperature operation (> 300 degrees C) and in radiation hard environments, which could offer considerable system advantages.

Abstmct-At low temperatures, a mean free path of electrons in semiconductors may exceed device dimensions. Current-voltage characteristics, potentials, electrical field, and carrier distributions are calculated for a two-terminal device under such conditions when the electron transport is ballistic. Current-voltage characteristics of a "ballistic" FET are analyzed using an approach similar to the Shockley model. It is shown that very high drift velocities can be obtained at low voltages leading to high speed and low power consumption in possible applications in logic circuits. For example, GaAs logic devices with characteristic dimensions about a micrometer or less at 77 K will be comparable with or better than Josephson tunneling logic gates.

The modern integrated circuit evolved from developments at Fairchild Semiconductor during the late 1950s and early 1960s. Using information from laboratory notebooks, internal company memoranda, oral histories, and personal communications, this article reconstructs and analyzes the activities of the Fairchild development team, including the company's efforts to improve and market ICs during the early 1960s.

Electrical and Electronics Engineering: An International Journal (ELELIJ) is a Quarterly peer-reviewed and refereed open access journal that publishes articles which contribute new results in all areas of the Electrical and Electronics Engineering. The journal is devoted to the publication of high quality papers on theoretical and practical aspects of Electrical and Electronics Engineering. The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on Electrical and Electronics Engineering advancements, and establishing new collaborations in these areas. Original research papers, state-of-the-art reviews are invited for publication in all areas of Electrical and Electronics Engineering. Topics of interest include but are not limited to, the following Authors are solicited to contribute to the conference by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe significant advances in the following areas, but are not limited to  Advanced Power System and Control system  Analog and digital circuit design

The energy spectrum and density of states of graphene bilayer superlattices (SLs) are evaluated. We take into account doping and/or gating of the layers as well as tunnel coupling between them. In addition, we evaluate the transmission through such SLs and through single or double barriers. The transmission exhibits a strong dependence on the direction of the incident wave vector.

This work describes a novel system for device development that automates and fully integrates the workflow from test chip construction, from placement and routing to electrical test program generation. In addition to accelerating test chip and test program development, this system facilitates parameterized data analysis, thereby providing a framework that finally allows the user to realize the full benefits of complex and elegant experimental device designs. By utilizing a centralized database and eliminating parameter re-entry, the automation provided by this integrated approach eliminates many of the sources for human error while maximizing reuse between technologies.

An InP-based high-speed optical modulator is presented. The Schottky-i-n waveguide structure on InP-based material was used to reduce the switching voltage V and the excess loss, while maintaining high-modulation efficiencies. To minimize residual amplitude modulation and to improve power handling capability, the bulk electrooptic effect in InGaAlAs was utilized for phase shifting. As a result, a simple structure InAlAs-InGaAlAs Mach-Zehnder optical modulator with traveling-wave electrodes was fabricated and characterized. This device achieved a switching voltage V of 3.6 V, extinction ratio (>23 dB) and high-speed operation at 1.55-m wavelength.

Semiconductor devices generally take advantage of the charge of electrons, whereas magnetic materials are used for recording information involving electron spin. To make use of both charge and spin of electrons in semiconductors, a high concentration of magnetic elements can be introduced in nonmagnetic III-V semiconductors currently in use for devices. Low solubility of magnetic elements was overcome by low-temperature nonequilibrium molecular beam epitaxial growth, and ferromagnetic (Ga,Mn)As was realized. Magnetotransport measurements revealed that the magnetic transition temperature can be as high as 110 kelvin. The origin of the ferromagnetic interaction is discussed. Multilayer heterostructures including resonant tunneling diodes (RTDs) have also successfully been fabricated. The magnetic coupling between two ferromagnetic (Ga,Mn)As films separated by a nonmagnetic layer indicated the critical role of the holes in the magnetic coupling. The magnetic coupling in all semiconductor ferromagnetic/nonmagnetic layered structures, together with the possibility of spin filtering in RTDs, shows the potential of the present material system for exploring new physics and for developing new functionality toward future electronics.

Most of the thermal characterization of packaged semiconductor devices is carried out in the time domain by measuring and recording the values of a temperature sensitive electrical parameter (TSEP) as a function of time, during the heating or cooling transient caused by the application of a given power function, generally a step, to the device. Although this time response contains, within measurement resolution, all the relevant information about device thermal behaviour, the ''packed'' form of this information is not so convenient for its immediate use when we want to obtain a thermal model for further simulation or extract some information on device structure. Real and imaginary parts of device frequency response are a better way of dealing with measurement results because its ''unpacked'' form leads easily to thermal model and structural information.

We report on a cost-effective optical setup for characterizing light-emitting semiconductor devices with optical-feedback confocal infrared microscopy and optical beam-induced resistance change. We utilize the focused beam from an infrared laser diode to induce local thermal resistance changes across the surface of a biased integrated circuit (IC) sample. Variations in the multiple current paths are mapped by scanning the IC across the focused beam. The high-contrast current maps allow accurate differentiation of the functional and defective sites, or the isolation of the surface-emitting p-i-n devices in the IC. Optical beam-induced current (OBIC) is not generated since the incident beam energy is lower than the bandgap energy of the p-i-n device. Inhomogeneous current distributions in the IC become apparent without the strong OBIC background. They are located at a diffraction-limited resolution by referencing the current maps against the confocal reflectance image that is simultaneously acquired via optical-feedback detection. Our technique permits the accurate identification of metal and semiconductor sites as well as the classification of different metallic structures according to thickness, composition, or spatial inhomogeneity.

The offset voltage in heterojunction bipolar transistors (HBTs) can be read graphically from a plot combining the forward Gummel (FG) and reverse Gummel (RG) plots. We use a Gummel-Poon model to show when this graphical construction works, and illustrate the method with measurements for InP/InGaAs double HBTs.

Full Text (PDF) Abstract Full Text (PDF) Abstract Full Text (PDF) Trapping in 1nm EOT high-k / MG Abstract Full Text (PDF) Abstract Full Text (PDF) Abstract Full Text (PDF) Electrical and Chemical Properties of the HfO2/SiO2/Si Stack: Impact of HfO2 Thickness and Thermal Budget Abstract Full Text (PDF) Scanning Transmission Electron Microscopy Studies of Interface Abstract Full Text (PDF) Abstract Full Text (PDF) Abstract Full Text (PDF) Growth and Characterization of Alternative Gate Dielectrics by Molecular-Beam Epitaxy Abstract Full Text (PDF) Abstract Full Text (PDF) Atomic Layer Deposited Lanthanum-(Zirconate/Aluminate) Based High-K Dielectric Stacks For Future CMOS-Technology Abstract Full Text (PDF) Abstract Full Text (PDF) Thermally Stable Hf-silicate with Modification of Si Doping and Thermal Budget in MIM Capacitors Abstract Full Text (PDF) Abstract Full Text (PDF) Abstract Full Text (PDF) Abstract Full Text (PDF) Abstract Full Text (PDF) Abstract Full Text (PDF) Physical Characterization of the Metal/High-k Layer Interaction upon Annealing Abstract Full Text (PDF) Abstract Full Text (PDF) Real Space Surface Reconstructions of Decapped As-rich In0.53Ga0.47As(001)-(2×4) Abstract Full Text (PDF) Abstract Full Text (PDF) Abstract Full Text (PDF) Abstract Full Text (PDF) Abstract Full Text (PDF) Clear Get All Checked Abstracts

We report design, growth, and characterization of midwavelength infrared nBn photodetectors based on a type-II InAs/InAs1-xSbx superlattice
on a GaSb substrate grown by metal-organic chemical vapor deposition. An InAs/AlAs1-ySby/InAs/InAs1-xSbx superlattice design was
used as the large bandgap electron barrier in the photodetectors. At 150 K, the photodetector exhibits a peak responsivity of 1.23 A/W,
corresponding to a quantum efficiency of 41% at an applied bias voltage of 100mV under front-side illumination, with a 50% cut-off wavelength
of 4.6 um.

Sensor devices are an integral part of human movement analysis.  The use of sensors in sports performance and injury prevention is extremely useful.  Over the years wireless systems have become increasingly popular and the analysis of human movement has been therefore simplified.  Inertial measurement units are very popular in physical activity monitoring and have become readily available for consumers.  The use of more advanced sensors to measure electrical and mechanical muscle activity tend to be tethered devices, thus data collection on more complex movements is limited.  This paper looks at the need for wireless solutions to these sensors and the proposal for a multi-channel sensor which incorporates all the necessary sensors for complete human movement analysis.  Wireless systems have the advantage of allowing the participant or athlete to perform the movement in their ecologically valid environment while giving both reliable and accurate results to the practitioner.  In terms of human movement, to achieve accurate information about the position, kinematic and external forces of the segments of the body being studied, a single multi-channel sensor device is necessary.  The combination of sensors in one device can give accurate information on muscle activity, forces, directionality and acceleration.

An overview of a variety of examples that deploy intelligent manipulation of controllable magnetic fields is presented. Magnetic Field Assisted Assembly is described in detail as a future scalable manufacturing process for semiconductor device integration with significant improvement in yield and reduction in costs. Magnetic field augmented rotational system is presented as a future approach to energy needs in a number of situations. The proposed examples address applications in key areas of the economy including energy, healthcare, manufacturing and materials.

To qualify the feasibility of standard semiconductor materials and Schottky-barrier diodes (SBDs) for THz high-order harmonic generation and extraction, the harmonic intensity, intrinsic noise and signal-to-noise ratio are calculated by the Monte Carlo method when a periodic high-frequency large-amplitude external signal is applied to a semiconductor device. Due to very high signal-to-noise ratio heavily doped GaAs SBDs are found to exhibit conditions for frequency mixing and harmonic extraction that are definitively superior to those of bulk materials.

Zero-voltage switching (ZVS) is implemented using a half-bridge (HB) topology for high-frequency offline applications. Two ZVS techniques are discussed: one is a quasiresonant technique (QRC) the other a multiresonant technique (MRC). A breadboarded HB ZVS-QRC is presented which operates from a 300±50 V input with maximum output power of 75 W (5 V, 15 A) and an efficiency of 83.5% at low line and full load and 79.2% at high line and full load. In ZVS-MRCs, all semiconductor devices are operated with no abrupt changes of the voltage across the devices. The technique permits utilization of junction capacitances of all semiconductor devices and the transformer leakage inductance to form a multiple-resonant-tank network to implement zero-voltage switching for all semiconductor devices. Employing this technique, a HB ZVS-MRC is breadboarded with the same specifications as the HB ZVS-QRC. The efficiency of the HB ZVS-MRC is slightly lower than that of the HB ZVS-QRC, 81.7% at full load and low line and 78.5% at full load and high line

Electrical and Electronics Engineering: An International Journal (ELELIJ) is a Quarterly peerreviewed and refereed open access journal that publishes articles which contribute new results in all areas of the Electrical and Electronics Engineering. The journal is devoted to the publication of high quality papers on theoretical and practical aspects of Electrical and Electronics Engineering.

The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on Electrical and Electronics Engineering advancements, and establishing new collaborations in these areas. Original research papers, state-of-the-art reviews are invited for publication in all areas of Electrical and Electronics Engineering.

This letter introduces a method based on electroluminescence imaging to determine mappings of the local series resistance of large area semiconductor devices such as solar cells. The method combines the local electroluminescence emission ⌽ i ͑U͒ and its derivative ⌽ i Ј͑U͒ with respect to the applied voltage U. The combined analysis of these two quantities yields the local series resistance R i se and proves the physical validity of the used current transport model and thus the physical relevance of the determined R i se value. The method is verified on a monocrystalline silicon solar cell with local shunts and local series resistance problems.

The exact transmission co-efficient T c and reflection co-efficient R c of a one dimensional (1D) potential step, potential barrier, deformed step and asymmetrical potential barrier have been obtained. The nature of the T c and R c have been studied by varying potential parameters in all the above cases. Finally,a general FORTRAN program is developed for the calculation of T c and R c for all the above cases by using Gauss Elimination Method.

A novel electroplating system and approach for selectively coating of probe tips for wafer and package testing are presented. A Ni-alloy probe tip with an overcoat layer of 3.5um thick PdCo provided less tip wear and better electrical contact resistance performance in wafer testing. Microstructures of films resulting from different conditions of electroplating process were analyzed, most uniform films were obtained at 5 mA of plating current conditions. The probe tip wear throughout probe life testing was monitored which indicates PdCo film with Au underlayer establishes good electrical contacts.

Technology computer aided design (TCAD) of semiconductor devices exhibits the advantages of reduced development costs and development time. In this worka TCAD methodology has been developed for high-speed photodetectors. The calibration procedure for fixing the free parameters in the physical models employed in the simulation has been illustrated for a commercially available InGaAs/InP p–i–n photodetector. This approach has been illustrated using a specific example where the task was to optimize the absorption layer thickness of a novel photodetector structure.