130 kHz 7.5 kW current source inverters using static inductiontransistors for induction heating applications

A control scheme of a high-frequency high-power current source inverters using static induction transistors is described which aims at the suppression of the surge voltage and reduction of the switching loss during the commutation of current. The inverter is operated at a leading power factor, which requires the phase angle of the output current to be adjusted to each specific load point by the controller. The stable operation is verified by the experiments under the commutation inductance 1.8 μH, i.e., 18% reactance (130 kHz, 250 V, 30 A, base). As a result, the inverter efficiency is estimated to be 97%, excluding the loss of the drive circuit and the control circuit     

New micromechanical display using thin metallic films

A new mechanical display is described, working on a simple electrostatic principle and yielding good contrast ratio (20-25), low power consumption, and short response time (1 ms). The device, which relies on the torsion of thin Al straps and works at some tens of volts, is fabricated using standard IC technology.     

Small-sized MMIC amplifiers using thin dielectric layers

Miniaturized MMIC amplifiers utilizing a multilayer structure composed of thin film transmission lines are presented. The fundamental characteristics of the thin film transmission lines for use in microwave active circuits are discussed through calculations by numerical analysis. A two-stage low-noise amplifier, a single-stage wideband amplifier, and a balanced amplifier are designed within very small areas, while good performance is maintained. The results include that a Ka-band single-stage amplifier is fabricated in a 0.8 mm×0.6 mm area with a gain of 8.0-9.5 dB in the frequency range of 16-26.5 GHz and input/output return losses of better than 8 dB at 26.5 GHz. The proposed amplifier configurations can be applied to high density integration of one-chip MMIC modules     

Infrared detection of delaminations using induction heating

The paper presents nondestructive method of investigation of multilayer structures containing conducting material, such as thyristor structures. The proposed method is based on induction heating of examined object and infrared detection of temperature field. Infrared images of examined thyristor structures registered with the help of this method are presented. Short discussion of advantages and disadvantages of the method is also included. The main benefit from usage of the proposed method is extremely short time of registration. Therefore, this method can be applied in industry for quick quality assessment of thyristor structures. Moreover, the source of excitation does not dazzle the infrared detector. Obtained preliminary results confirm usability of the method.     

Complex dispersion relation of 1D dielectric photonic crystal with thin metallic layers

We have carried out the analytical and numerical analysis of metallic insets embedded in a dielectric photonic crystal (DPC). The corresponding one-dimensional metallo-dielectric photonic crystal (MDPC) is studied in relation to the substratum DPC. We describe the complex MDPC dispersion relation curves and the transmission coefficient at the different propagation regimens trough the finite stack. While in the DPC, the band gap argument corresponds to undefined complex solutions of a real dispersion relation, in a MDPC corresponds to a definite complex solution, function of the metal thickness; and analytic continuation of the dispersion curve on the imaginary K plane. The metal absorption is described by the Drude model, and as a result of the absorption in the inset metallic films, complex Bloch vectors are produced for all frequencies as evanescent waves that differ from the straightforward metal absorption.     

Multilayer MMIC directional couplers using thin dielectric layers

Low-loss and small-sized MMIC directional couplers utilizing a multilayer structure composed of coupled thin-film transmission lines on a GaAs wafer surface are newly proposed. The fundamental characteristics of the couplers are discussed through calculations by numerical analysis, and the performance of the couplers and an application to reverse-phase hybrid ring are demonstrated. The results show that a 3 dB coupler can be designed within a 0.8 mm×0.8 mm area for a center frequency of 20 GHz. Coupling losses of 3.7 dB±0.2 dB over a 4-GHz bandwidth and isolation of better than 26 dB in the frequency range of 0-30 GHz are achieved. The proposed coupler configurations can be applied to the high-density and multifunction integration of MMIC's     

Active layers for device applications by using high-energy selenium implantation into GaAs

High-energy, doubly charged selenium ions have been used to produce dopant profiles suitable for GaAs devices, such as f.e.t.s. Selenium has the advantage that beams of high purity may be formed.     

Oscillator-circuit thyristor converters for induction heating

For the induction heating of metals it is advisable in many cases to use higher frequencies. So far, the input required has been supplied by rotary converters or high-vacuum tubes. Recently, static converters with thyristors have also been employed. Equipment already installed is described, and details are given on the considerations leading to the solution adopted.     

Ultra-low-energy ion-beam-synthesis of Ge nanocrystals in thin ALD Al2O3 layers for memory applications

Structural and electrical properties of ALD-grown 5 and 7 nm-thick Al₂O₃ layers before and after implantation of Ge ions (1 keV, 0.5–1 × 10¹⁶ cm^?2) and thermal annealing at temperatures in the 700–1050 °C range are reported. Transmission Electron Microscopy reveals the development of a 1 nm-thick SiO₂-rich layer at the Al₂O₃/Si substrate interface as well as the formation of Ge nanocrystals with a mean diameter of ～5 nm inside the implanted Al₂O₃ layers after annealing at 800 °C for 20 min. Electrical measurements performed on metal–insulator–semiconductor capacitors using Ge-implanted and annealed Al₂O₃ layers reveal charge storage at low-electric fields mainly due to location of the Ge nanocrystals at a tunnelling distance from the substrate and their spatial dispersion inside the Al₂O₃ layers.     

Low-temperature pulsed CVD of thin layers of metallic ruthenium for microelectronics and nanoelectronics. Part 3: Nucleation phenomena during the growth of ruthenium layers

The data on the peculiarities of nucleation and initial stages of the growth of ruthenium layers on different surfaces in the temperature range 110–350°C under the pulsed deposition from the vapor phase with the participation of the carbonyl-diene precursor Ru(CO)₃C₆H₈, as well as NH₃, N₂O, and H₂ as the second reagent are generalized.     

Low temperature pulsed gas-phase deposition of thin layers of metallic ruthenium for micro- and nanoelectronics: Part 2. Kinetics of the growth of ruthenium layers

Experimental data of growth kinetics of layers of ruthenium in a temperature range of 110–350°C by pulsed deposition from the gas phase with the participation of the carbonyl-diene precursor complex Ru(CO)₃(C₆H₈), as well as NH₃ and N₂O as the second reagent are generalized.     

Gaq3有机薄膜电致发光器件

首次报道了采用８－羟基喹啉镓螯合物作为发光层制备有机薄膜电致发光器件，器件的结构为：ＩＴＯ导电玻璃／ＴＰＤ／Ｇａｑ３／Ａｌ。研究了Ｇａｑ３薄膜的光致发光和器件的电致发光机理，同时测量和研究了器件的电流密度－－电压（Ｊ－Ｖ）特性和发光亮度－电压（Ｂ－Ｖ）特性。结果表明器件的电致发光峰值波长为５４０ｎｍ，在２０Ｖ直流电压驱动下的最大发光亮度约２５００ｃｄ／ｍ＾２明显高于上同结构和工艺参数制备的Ａｌｑ３     

Drift mobility measurements in thin epitaxial semiconductor layers using time-of-flight techniques

The conventional time-of-flight technique for measuring drift velocity in high mobility semiconductors is limited to relatively thick (> 200 μm) and high resistivity material. The microwave time-of-flight technique described here allows thin (～ 10 μm) low resistivity epitaxial layers to be measured with greater accuracy than is afforded by the conventional technique. The new experimental method is applied to the measurement of electron drift velocity in n-type GaAs at room temperature. The method, and its theory, is described in detail and its advantages and limitations are discussed.     

Composition and thickness control of thin LPE HgCdTe layers using x-ray diffraction

Double-axis x-ray rocking curve measurements have been used to nondestructively characterize the composition profile of HgCdTe heterojunction photodiode structures grown by liquid phase epitaxy (LPE). In particular, the thickness and composition profile of the thin graded-composition cap layer are determined through an empirical correlation between rocking curve parameters and composition profiles measured by SIMS. Spatial maps of cap layer thickness and composition are generated from automated measurements of x-ray rocking curves across a wafer. X-ray mapping has been instrumental in improving the spatial uniformity of cap layers and in maintaining control of the growth process in Hg-rich LPE dipping reactors.     

Properties of amorphous carbon layers for bio-tribological applications

This paper analyses the influence of composition, structure and adhesion of amorphous coatings with high wear resistance, low friction coefficient and good adhesion to coated CrCoMo material for parts of implants. By different deposition techniques, different mechanical and tribological properties were obtained. This work reviews amorphous carbon (a-C) films deposited by magnetron sputtering and diamond-like carbon (DLC) films grown by glow arc discharge technology on CrCoMo substrates. Films were investigated under static load under dry conditions (nanohardness, elastic module), and also with dynamic load (coefficient of friction, wear resistance). The following topics were investigated: surfaces and subsurface properties of a-C films, namely adhesion in connection with different techniques, different film properties in dependence on various technology conditions.     

Flanged coaxial microwave probes for measuring thin moisture layers

We obtain an analytical, closed-form expression for the input admittance of a flanged, open-ended coaxial line radiating into a layered lossy material. The effect of higher modes as well as the dominant mode have been taken into consideration. The results obtained in the experimental measurement of the microwave reflection coefficient of the probe radiating into very thin water layers are described and compared with the results obtained from numerical calculations based on a theoretical model. The measurements were made in the 5.0-7.0 GHz range. The results demonstrate, for example, the usefulness of this type of device in measuring thin moisture layers in the outer layer of the human skin.     

Fringe field corrections for capacitors on thin dielectric layers

An approximate formula is derived which yields the fringe field correction explicitely in terms of the parameters of the electrode configuration for the frequently encountered case of plane parallel electrodes, of which one is circular and the other infinitely large. Other related cases are also discussed. The error is typically of the order of 1%. The formulae are useful in determining the dielectric constants of crystalline platelets.     

RFID超薄抗金属标签天线设计

设计了一款UHF频段RFID超薄抗金属电子标签天线,该天线采用Koch分形结构实现小型化。天线采用FPC材料作为标签天线的介质基板,厚度仅为0.25 mm。其良好的柔韧性使其能用于有共形要求的场合。仿真和测试表明,提出的天线具有较宽的带宽(900~930 MHz)、相对高的增益(约–10.7 d B)、较高的天线效率及较大的阅读距离(约3 m),可应用于物联网中对金属物体的管理。     

Self-assembled metallic nanocrystal structures for advanced non-volatile memory applications

Nanocrystal (NC) based non-volatile memories are a leading candidate to replace conventional floating gate memory. Substituting the poly-silicon gate with a layer of discrete nanocrystals or nanodots provides increased immunity to charge loss. Metallic nanocrystals have been found to be advantageous over Si- or Ge-based approaches due to good controllability of the size distribution and the achievable NC densities as well as increased charge storage capacity of metallic nanocrystals. Sufficiently high NC densities have been achieved to demonstrate feasibility for sub-32 nm node non-volatile memory devices.     

Polarisation referencing in refractometry using fibre to planarwaveguide couplers incorporating thin metal layers

The wavelength response of fibre to metal clad planar waveguide couplers has been investigated as a function of superstrate index. The TE resonance wavelengths remain fixed with superstrate index variation while the TM resonance position demonstrates good superstrate index sensitivity. Such a technique may be used for polarisation referencing and temperature compensation in refractometry