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PL
W artykule przedstawiono właściwości rezystancyjnego czujnika gazowego chloru z warstwą aktywną wykonaną z tlenku cynku domieszkowanego platyną. Materiał gazoczuły syntezowano metodą hydrotermalną (CBD). Badania za pomocą skangowego mikroskopu elektronowego (SEM) oraz metodą dyfrakcji rentgenowskiej (XRD) wykazały, że otrzymano mikropręty tlenku cynku domieszkowane metaliczną platyną. Analizę właściwości sensorowych przeprowadzono w obecności 2 ppm Cl2 w atmosferze o różnej wilgotności. Uzyskane wyniki wykazały, że konduktancja warstwy gazoczułej maleje w obecności gazowego chloru a jej wartość zależy od wilgotoności badanej atmosfery. W atmosferze o wilgotności względnej 75% czułość sensora jest na podobnym poziomie jak w powietrzu o wilgotności 30% RH, natomiast w 90% RH znacznie maleje.
EN
This article shows the resistive chlorine sensor with active layer made of zinc oxide doped with platinum. The sensing material was synthesized by hydrothermal methode (CBD). Scanning electron microscope (SEM) and X-ray diffraction (XRD) showed that zinc oxide microrods doped with platinum were obtained. Sensing analysis was performed in the presence of 2 ppm of Cl2 in atmospheres of varying humidity. The obtained results have shown that the conductivity of the active layer decreases in the presence of chlorine and its value depends on the moisture content of the tested atmosphere. At 75% RH the system sensitivity is similar to 30% RH, while 90% RH is significantly reduced.
2
Content available remote Ga2O3 nanowires preparation at atmospheric pressure
EN
An attempt has been undertaken to produce gallium oxide nanowires by thermal synthesis from metallic gallium source at atmospheric pressure. Silicon substrates of (1 0 0) and (1 1 1) orientation with and without silicon oxide layers (0.5 μm) were used as support. Evaporated thin gold films were deposited on the top of those silicon carriers as a catalytic agent. After thermal treatment by Rapid Thermal Processing RTP (at various temperatures and times), which was applied to make small Au islands with the diameters of about several tens of nanometers, the substrate surfaces were observed by SEM. The Ga2O3 syntheses were made at various conditions: time, temperature and gas mixture were changed. As a result, monoclinic gallium oxide β- Ga2O3 nanostructures with dominant [1 1 1] and [0 0 2] growth directions were grown. The obtained nanostructures of several tens micrometers length were studied by SEM, PL and X-ray methods.
PL
W artykule przedstawiono metodę otrzymywania mikroprętów ZnO na szklanych podłożach pokrytych ITO metodą chemical bath deposition w polu elektrycznym. Badania XRD potwierdziły uzyskanie struktur o heksagonalnej strukturze typu wurcytu, w których rozmiar krystalitów oraz naprężenia znacznie zależą od temperatury prowadzenia procesu osadzania. W strukturach ZnO o największym stopniu uporządkowania zmierzony moduł piezoelektryczny d33 wynosił 16,61 pm/V.
EN
The paper was presented a method for obtaining zinc oxide microrods on glass substrates coated with ITO. ZnO microrods were obtained by the chemical bath deposition method in the electric field, which allowed obtain the layers with a high level of order. XRD confirmed that obtained structure is hexagonal wurtzite type in which the crystallite size and stress depend on the temperatures of the deposition process. In the most ordered ZnO structures, the measured d33 piezoelectric module was 16.61 pm/V.
4
EN
The main goal of the studies on epitaxial regrowth process of InP on patterned substrates is to gain knowledge about growth rates and interface quality on various areas to improve the fabrication technology for future applications. Prepared samples were measured at every step of the process by scanning electron microscope (SEM), optical microscope with dark field and phase contrast modes, atomic force microscope (AFM) and also using optical profilometer WLI (White Light Interferometer). Fabrication steps were divided into three main groups. First was the epitaxial growth of 5 µm thick InP layer. Next was patterning, which was made by applying a mask film on the epilayer. Shapes of the mesas after wet chemical etching with photoresist as a mask as well as the shapes of mesas slopes were irregular on the whole substrate area. These problems were solved by the use of silicon nitride mask. The mesas shapes and their slopes became then regular, independently of etching depth. Second fabrication step was etching of selected area. Couple of solutions were examined, but in details HCl:H3PO4 mixture in various proportions, which gave the best results in mesas shapes and orientations relative to the substrate. After that, the etching mask material was removed from the epilayer using a buffered hydrofluoric acid (BHF). The last step was epitaxial regrowth. To see how the epitaxial growth process was performed on different areas of patterned substrate it was suggested using a “sandwich”, which consisted of 50 layers of indium phosphide and indium gallium arsenide. This idea helped to understand the phenomena occurring during the epitaxial growth on that kind of substrate. The highest growth rate occurred on the top of the mesas and the lowest on their slopes. Described experiments are introduction to the studies on epitaxial growth of buried heterostructure (BH).
5
Content available remote Impact of processing parameters on the LTCC channels geometry
EN
A great advantage of Low Temperature Co-fired Ceramics (LTCC) yields the possibility of channel and air cavity fabrication. Such empty spaces have numerous applications, for example, in microfluidics, microwave techniques and integrated packaging. However, improper geometry of these structures can degrade the performance of the final device. The processing parameters recommended by the LTCC tape supplier are relevant for the production of multilayer circuits but not surface embedded channels and/or cavities. Thus, it is important to examine which factors of the fabrication process are the most significant. In our study, special attention has been paid to the geometric performance of the channel structure resulting from the applied processing parameters. Laser cutting parameters were checked to obtain the structures with great fidelity. The impact of an isostatic lamination on the quality of the final structure was analyzed. The influence of pressure and temperature of the lamination process on the channel geometry and tape shrinkage were examined. The performed experiments showed that some improvements in channel/cavity geometry may be achieved by optimizing the processing procedures. The microscopic observations combined with the Analysis of Variance (ANOVA) showed which combinations of the processing parameters are the best for achieving a channel/cavity structure with the desired geometry.
EN
Studies on electromigration phenomenon in thick-film structures on alumina and LTCC substrates are presented in this paper. The effects of storage of Au and Ag electrode patterns in temperature range up to 300 °C under voltage bias were examined. The leakage characteristics of electrodes with 100 μm spacing at 50 V dc bias as a function of time and temperature are presented and analyzed. Scanning electron microscope (SEM) equipped with the energy-dispersive X-ray spectroscopy (EDX) detector was applied for determination of metal ions transport. Test structures with Au-based conductive material are much more resistant to electromigration than Ag-based layers.
EN
In this study, the results of reactive ion etching (RIE) process of diversified Al content AlxGa1–xN/AlN/GaN/sapphire heterostructures were presented. The Al fractions of 22, 25, 31 and 36% were examined. An impact of Al content in the heterostructures on the etch rates and surface morphology was investigated. The influence of used Cl2/BCl3/Ar gas mixture with varying of BCl3 flow on the etch rate of Al0.2Ga0.8N/GaN/sapphire, surface morphology and angle of mesa slope, was discussed.
8
Content available remote Stability of ZnO nanofibers in processing liquid agents
EN
The aim of the research was to determine the impact of developers, removers and solvents on the stability of ZnO nanofibers. Surface imaging of nanofiber morphology was studied using Scanning Electron Microscope. From the obtained results a set of factors which have the least influence on the etching of ZnO nanofibers during device processing was selected. The dependence of the grains size on the fibers robustness in the liquid solutions was investigated. It was found that the nanofibers calcinated at higher temperatures were more stable. This was due to the grain size of the fiber as the fibers calcinated at higher temperatures revealed larger grain size. The studies have shown that smaller grains were dissolved much faster, leaving the porous core of the ZnO nanofiber.
PL
W pracy przedstawione zostały wyniki charakteryzacji lokalnych właściwości detektorów MSM (Metal-Semiconductor-Metal) oraz rezystancyjnych wytworzonych w warstwach GaN, struktur tranzystorów unipolarnych wykonanych w warstwach azotku galu, cienkich warstw metali katalitycznych, heterostruktur AlAs/AIGaAs/GaAs oraz powierzchni węglika krzemu wykonanych różnymi trybami mikroskopii sił atomowych. Badania zostały przeprowadzone metodami Skaningowej Mikroskopii Potencjału Powierzchniowego SSPM (ang. Scanning Surface Potential Microscopy), Skaningowej Mikroskopii Rezystancji Rozproszonej SSRM (ang. Scanning Spreading Resistance Microscopy) oraz obrazowania fazowego.
EN
In this work characterization results of MSM (metal-semiconductor-metal) and resistive detectors fabricated in gallium nitride layers, GaN based unipolar transistors, thin catalytic metal layers, AlAs/AIGaAs/GaAs heterostructures and silicon carbide surface by various techniques of atomic force microscopy are presented. The examinations were performed by Scanning Surface Potential Microscopy (SSPM), Scanning Spreading Resistance Microscopy (SSRM) and in phase imaging mode.
EN
A designing problem of the monastery can be generally described as a difficulty in creating the space of sacrum, i.e. the space which facilitates concentration and which has a tranquilizing influence on the user. The analysis of the existing solutions, although it is helpful in understanding the phenomenon, does not constitute the primary source of knowledge. A greater emphasis should be placed on man, man’s psyche, and various ways of exploring and feeling the space.
PL
Problem projektowy klasztoru można ogólnie opisać trudnością w wykreowaniu przestrzeni sacrum, przestrzeni, która ma uspakajający, ale ułatwiający skupienie wpływ na użytkownika. Analiza istniejących rozwiązań, jakkolwiek pomocna w zrozumieniu zjawiska, nie jest podstawowym źródłem wiedzy. Skupić by się bardziej należało na człowieku, na jego psychice, sposobach poznawania przestrzeni i jej odczuwania.
11
Content available remote Application of AFM technique for creation of patterns in nanoscale
EN
The lithography is a main technology process which determines the properties of semiconductor devices. The resolution of optical lithography is insufficient for creation of submicrometer patterns, like, e.g., gate electrode in HEMT transistors. Thus, a novel technique that uses AFM technique and common photolithography was proposed. In the paper, the results of nanoscratching lithography were presented and discussed. Also the transmission and root mean square of thin metal films measurements were summarized.
12
Content available remote Properties of AlNx thin films prepared by DC reactive magnetron sputtering
EN
In this paper, the results of investigation of the influence of cathode current on optical and dielectric AlNx thin-film properties are presented. AlNx films were prepared by pulsed DC reactive magnetron sputtering of Al target on substrates at room temperature. For characterization of fabricated test structures C-V spectroscopy, ellipsometry measurement and atomic force microscopy (AFM) were used.
EN
Ohmic contacts to AlGaN/GaN heterostructures which have low contact resistance and good surface morphology are required for the development of high temperature, high power and high frequency electronic devices. One of the keys to the advancement of such devices is the understanding of ohmic contacts formation to epitaxial aluminium gallium nitride layers. The paper presents the investigation of Ti/Al/Ni/Au based ohmic contact to n-AlGaN/GaN heterostructures grown by LP-MOVPE technique. Multilayer metallization of Ti/Al/Ni/Au with thicknesses of 10/100/40/150 nm, respectively, was evaporated by an electron gun (Ti, Ni) and resistance heater (Al, Au). The contacts were annealed at RTA (rapid thermal annealing) system in nitrogen ambient atmosphere over the temperature range from 775 °C to 850 °C. The time of annealing process was 60 seconds. The morphology of Ti/Al/Ni/Au ohmic contacts to n-AlGaN/GaN heterostructures was studied as a function of the annealing process conditions by an optical microscope and AFM (atomic force microscope). Simultaneously, the electrical parameters of Ti/Al/Ni/Au ohmic contacts were studied as a function of the annealing process conditions by the current-voltage (I-V ) method on dedicated test structures. The characteristic resistances of the Ti/Al/Ni/Au/n-AlGaN/GaN ohmic contacts were evaluated from the circular transmission line method (CTLM). The formation and deterioration mechanisms of the ohmic contacts to n-AlGaN/GaN hesterostructures were studied. One of the mechanisms of agglomerates enlargement during the thermal annealing of Ti/Al/Ni/Au metallization has been proposed.
PL
W artykule przedstawiono sposób określenia dolnej i górnej granicy obszaru pomiarowego mierników impedancji i rezystancji obwodu zwarciowego, typu "mieszkaniowego", o nierozdzielonych torach napięciowych i prądowych, i typu "przemysłowego", o rozdzielonych torach. Przedstawiona procedura pomiarowa dostarcza informacji, których z reguły nie podają producenci mierników.
PL
Przedstawiono procedurę pomiarową umożliwiającą wyznaczenie dolnej granicy obszaru pomiarowego mierników impedancji i rezystancji obwodu zwarciowego, nie wymagającą stosowania specjalizowanych przyrządów i układów.
EN
The paper presents a measurement procedure, which allows for estimation of the lower end of measurement range for earth fault loop impedance meter. The procedure does not require specialized devices and set-ups.
PL
W artykule przedstawiono analizę porównawczą metod: techniczną, różnicową, różnicową z przestawieniem i różnicową z podstawieniem stosowanych w pomiarach impedancji obwodu zwarciowego. Rozważania przeprowadzono dla układów przetwarzających sygnały analogowe oraz przy założeniu, że przebiegi napięcia i prądu są sinusoidalne. Uzyskane wyniki pokazują że najlepszymi parametrami, przy powyższych założeniach, charakteryzuje się metoda różnicowa z przestawieniem. Przedstawiona analiza nie uwzględnia zagadnień obliczeniowych oraz wpływu zastosowania przetworników analogowo-cyfrowych w torach pomiarowych, dotyczy ona tylko analizy wpływu metody na dokładność pomiaru.
EN
Comparative analysis based on the classical metrological analysis of earth fault loop impedance (short circuit loop impedance) measurement methods was presented. Four methods were analysed. These were technical method, differential method, dif-ferential with replacement method and differential with substitution method. The analysis was carried out for analogue signal processing layouts assuming sinusoidal waveform of source supply. Also the influence of different ratios of casual to systematic errors on the meas-urement error was analysed. Considering this, obtained results point out to the differential method with re-placement as the best. Presented analysis does not concern calculation issues or the consequences of using analogue-to-digital converters. It is dedicated to the assessment of influence of measurement method on accuracy of loop impedance measurement.
PL
W artykule przedstawiono klasyczną analizę metrologiczną metod pomiarowych stosowanych w pomiarach impedancji obwodu zwarciowego. Przeanalizowano metody: techniczną, różnicową, różnicową z przestawieniem i różnicową z podstawieniem. Rozważania przeprowadzono dla układów zbudowanych tylko z przetworników analogowych i wykonujących operacje na sygnałach analogowych oraz przy założeniu że zasilanie jest sinusoidalne. Przedstawiona analiza nie uwzględnia zagadnień obliczeniowych oraz wpływu zastosowania przetworników analogowo-cyfrowych, dotyczy ona tylko analizy wpływu metody pomiaru na dokładność pomiaru.
EN
The paper presents the metrological analysis of earth fault loop impedance (short circuit loop impedance) measurement methods. Four methods were analysed: voltme-ter and ampermeter method, differential method, differential with replacement method and differential with substitution method. The analysis was carried out for analogue signal processing layouts assuming sinusoidal waveform of source supply. Presented analysis does not concern calculation issues or the consequences of using analogue-to-digital converters. It is dedicated to the assessment of influence of meas-urement method on measurement accuracy.
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