Vibration analysis of the tension shadow mask with wire impact damping

Non-linear vibration of the CRT shadow mask with impact damping wires is analyzed in consideration of the mask tension distribution and the effect of wire impact damping. A reduced order FEM model of the shadow mask is obtained from dynamic condensation of the mass and stiffness matrices, and damping wire is modelled using the lumped parameter method to effectively describe its contact interactions with the shadow mask. The non-linear contact-impact model is composed of spring and damper elements, of which parameters are determined from the Hertzian contact theory and the restitution coefficient, respectively. The analysis model of the shadow mask with damping wires is experimentally verified through impact tests of shadow masks performed in a vacuum chamber. Using the validated analysis model of the shadow mask with damping wires, the ‘design of experiments’ technique is applied to search for the optimal damping wire configuration so that the vibration attenuation of the shadow mask is maximized.     

Chemical Analysis of Patterned Mask Cleaning in Organic Light Emitting Diode Fabrication with Raman Spectroscopy

Abstract

Despite the continually improving efficiency of the fabrication process used to manufacture the organic light emitting diode (OLED) emitter layer, which uses a shadow mask, a method for the cleaning and recycling of the shadow mask is still lacking. One of the main reasons for this is the absence of a quantitative/qualitative method to analyze the cleaning solution using simple in situ measurements. Recently, Raman analysis has become popular because of its convenience, ease of use, and suitability for in situ measurements. Thus, Raman spectroscopy has the capacity to analyze the solution used for cleaning shadow masks. A particular advantage of this approach is that it can detect organic contaminants in the cleaning solution, which are caused by the residue that remains on the shadow mask after the OLED emitter layer fabrication process. Raman spectroscopy has an advantage for analyzing solution condition and contaminant detection between the cleaning solution and organic chemical by using the Raman peak and fluorescence integration method.     

Stencil lithography of gold-black IR absorption coatings

Gold black coatings are deposited through a stencil shadow mask to produce infrared-absorbing patterns with sub-mm lateral dimensions. Such dimensions match the characteristic pitch of Long Wave Infrared (LWIR) array bolometers. Infrared spectral imaging with sub-micron spatial resolution reveals the spatial distribution of absorption across the pattern.     

Direct fabrication of physical relief structures via patterned photodeposition of a titanium alkoxide solution

Ultraviolet (lambda=248 nm) excitation of a photosensitive Ti alkoxide solution was found to generate a metal-oxide-based insoluble film on substrates in contact with the solution during illumination. Patterned deposition of 100 microm wide lines of material was demonstrated using a slit-shaped aluminum shadow mask during exposure. Stylus profilometry confirmed that the average thickness of the photodeposited film monotonically varied with accumulated UV fluence, exhibiting thicknesses of 10 to 310 nm for fluences of 12 and 192 J/cm(2), respectively. Moreover, the surface profile of the film surface at fluences greater than 12 J/cm(2) was found to reproduce the near-field Fresnel diffraction pattern anticipated from the slit mask used.     

Polarization-encoded optical shadow casting: an efficient multiprocessor design using truth-table partitioning

An efficient multiprocessor has been designed using a polarization-encoded optical shadow casting truth table partitioning scheme. As an example, the design algorithm for identifying the source patterns, input patterns, and output mask for the design of an adder-subtracter is presented.     

Charging effects of ErAs islands embedded in AlGaAs heterostructures

Self-assembled ErAs islands were grown on GaAs between a two-dimensional electron gas (2DEG) and a backgate electrode by molecular-beam epitaxy. The islands have overlapping Schottky barriers that form an insulating potential barrier. A TiAu topgate was added by shadow mask evaporation. Thermal activation and charging experiments were employed to gain insight into the electronic properties of the ErAs island systems. In addition the 2DEG was characterized as a function of topgate and backgate voltage.     

Nanostructuring of single crystal diamond by reactive and non-reactive accelerated cluster erosion

Reactive accelerated cluster erosion (RACE) of single crystal artificial diamond has been used to fabricate various nano- and microstructures. Carbondioxide clusters of about 1000 molecules are accelerated to 100 keV to act as the eroding agent. Using movable shadow masks, the accelerated cluster beam may erode staircase structures acting as an optical grating. A cycloid gear has been generated via a stationary nickel mask. Non-reactive accelerated cluster erosion using argon clusters will be considered for comparison. Received 30 November 2000     

Optical modes in wavelength-sized organic microcavity structures

We show the impact of lateral structuring on the optical properties of organic thin films in microcavities. The active material tris-(8-hydroxy quinoline) aluminium (Alq₃) was deposited using shadow mask evaporation, resulting in various micron sized shapes. A simplified box model is employed to describe the steady state electric field distribution in these mesa cavities. The complex mode structure measured in transmission and photoluminescence is confirmed by a transfer matrix calculation and a Fourier transform of the internal electric field distribution.     

利用金属掩模法制备钉扎型磁性隧道结

利用金属掩模法和Ir22Mn78合金反铁磁钉扎层，制备了四种钉扎型的Py/Al2O3/Py，Py/Al2O3/Co，Co/Al2O3/Py和Co/Al2O3/Co磁性隧道结，坡莫合金的成分为Py＝Ni79Fe21.例如：利用狭缝宽度为100?μm的金属掩模，直接制备出室温隧穿磁电阻比值为17.2%的磁性隧道结Co/Al2O3/Co，其结电阻为76Ω,结电阻和结面积的积矢为76×10_{4Ωμm2，自由层的偏转场为1114?A/m，并且在外加磁场0.1114A·m-1之间时室温磁电阻比值 关键词： 磁性隧道结 隧穿磁电阻 磁随机存储器 金属掩模}     

Photoluminescence behavior of ZnO nanorods produced by eclipse PLD from a Zn metal target

In this work, arrays of one-dimensional ZnO nanostructures were deposited on c-axis sapphire by standard and eclipse pulsed laser deposition (EPLD) using a metallic Zn target. One reference sample was grown by standard PLD and nine were grown by EPLD using a 16 by 16 mm² square shadow mask. Three shadow mask positions were used, with three depositions at varying oxygen pressures for each mask position. The oxygen partial pressure was between 100 and 200 mTorr for all growth procedures with a substrate temperature of 600 C.SEM reveals that arrays of nanorods are formed when growing by standard PLD. When grown by EPLD the rods tend to clump together with ordering on the micron scale. Low temperature photoluminescence was carried out as a function of position over several of the samples with 1 or 2 mm spacing. In general, it was found that the luminescence intensity is maximum in the center of the samples and falls off toward the edges while the shape stays roughly the same. Free exciton emission was resolved in most samples along with several other emission peaks from donor-bound excitons. The integrated PL intensity for all the EPLD samples is an order of magnitude higher than for the standard PLD sample. Linewidths are significantly reduced as well. Hence, the EPLD grown samples have superior optical quality and this growth technique shows promise for growth of high quality ZnO nanostructures.     

Undercut structures fabricated by microtransfer printing combined with UV exposure and their applications

In this paper, the undercut structures were fabricated by microtransfer printing of metal films on the surface of photoresist combined with UV exposure and photoresist film developing. The patterned metal films were used as mask to realize the selective UV exposure of photoresist firstly. The undercut structures, which consist of the top metal films and the patterned bottom photoresist, formed in the subsequent developing process because of the lateral dissolving of photoresist at the edge of the unexposed regions. The method proposed in this paper has wider tolerance to the changing of the patterning parameters, but without effect on the patterning resolution since the metal film was used as the top layer. The undercut structures were used as separators to pattern passive-matrix display of organic light-emitting diodes (OLEDs). No visible difference of the device performance was observed compared with the OLEDs patterned by the shadow mask.     

Ultrafast tilting of the dispersion of a photonic crystal and adiabatic spectral compression of light pulses

We demonstrate, by theory and experiment, the ultrafast tilting of the dispersion curve of a photonic-crystal waveguide following the absorption of a femtosecond pump pulse. By shaping the pump-beam cross section with a nanometric shadow mask, different waveguide eigenmodes acquire different spatial overlap with the perturbing pump, leading to a local flattening of the dispersion by up to 11%. We find that such partial mode perturbation can be used to adiabatically compress the spectrum of a light pulse traveling through the waveguide.     

A shadowed off-axis production of Ge nanoparticles in Ar gas atmosphere by pulsed laser deposition

In this work, we report on the production of Ge nanoparticles (NPs) in an inert Ar gas atmosphere by pulsed laser deposition (PLD) at room temperature (RT). The direct deposition of energetic particles/droplets resulting from the ablation process of the target material has been avoided by using an original and customized off-axis shadow mask (shadowed off-axis) deposition set-up where the NPs deposition on the substrate takes place by means of scattering between the NPs formed in the vapor phase and the background Ar atoms. It is found that the Ar gas pressure parameter has a relevant role in the crystallization process, with better crystallinity obtained as the background Ar pressure is raised for the given experimental conditions.     

Top contact organic field effect transistors fabricated using a photolithographic process

This paper proposes an effective method of fabricating top contact organic field effect transistors by using a pho-tolithographic process.The semiconductor layer is protected by a passivation layer.Through photolithographic and etching processes,parts of the passivation layer are etched off to form source/drain electrode patterns.Combined with conventional evaporation and lift-off techniques,organic field effect transistors with a top contact are fabricated suc-cessfully,whose properties are comparable to those prepared with the shadow mask method and one order of magnitude higher than the bottom contact devices fabricated by using a photolithographic process.     

Dual-functional diffraction grating based on selective metal deposition of photochromic diarylethene

Dual-functional diffraction gratings, which show different diffractions in transmission and reflection, are proposed as an essential optical element. We utilize a flattening effect of photochromic diarylethene (DAE) in the low glass transition temperature state and selective metal deposition to prepare the gratings. The uncolored lines of the colored DAE layer on a grating substrate with grooves were formed by red-laser scanning, and Mg evaporation onto the substrate without a shadow mask enabled Mg-line formation at right angles to the grooves. After being stored at 27 °C for 500 min, the sample showed two-dimensional diffraction in reflection but one-dimensional diffraction in transmission, meaning that a dual-functional grating was achieved. This result shows great potential as a key element for various future optical devices and systems.     

Visualization of the inverse layer-plus-island growth in Fe islands on W(110) substrate

Many experiments have been conducted so far to control the growth mode in heterostructures, but success has only been restricted to strain-controlled growth systems. In this study, using the shadow mask deposition technique, we have changed the growth mode in the Fe/W heterostructures from the layer-plus-island growth mode to island-plus-layer growth mode. From this, we have ignited the competing growth between forming the islands and wetting the first layer, and have directly visualized the island-plus-layer growth by controlling the annealing temperature of the system. This unconventional growth mode may play an important role in studying the hidden boundaries of hetero-interfaces.     

Straight single-crystalline germanium nanowires and their patterns grown on sol-gel prepared gold/silica substrates

Straight single-crystalline Ge nanowires with a uniform diameter distribution of 50-80 nm and lengths up to tens of micrometers were grown in a high yield on sol-gel prepared gold/silica substrates by using Ge powder as the Ge source. Detailed electron microscopy analyses show that the nanowires grow through a vapor-liquid-solid growth mechanism with gold nanoparticles located at the nanowire tips. By using transmission electron microscope grids as the shadow mask, the sol-gel technique can be readily adapted to prepare patterned film-like gold/silica substrates, so that regular micropatterns of Ge nanowires were obtained, which could facilitate the integration of Ge nanowires for characterization and devices.     

非对称开口六边形谐振单环的微波透射特性

受自然界树型结构的启发，设计了分叉树型微结构单元，用电路板刻蚀技术制作了非对称开口六边形谐振单环及其组合结构.采用计算机模拟和实验研究了单个和多个谐振环在微波段(7—12 GHz)的电磁响应行为.研究结果表明：该结构具有负磁导率特性，开口谐振环几何尺寸影响环的磁谐振频率；两环环间距较小时出现二次谐振；带高级分支的辐射状环列相对于不带分支环列透射峰向低频移动.实验和模拟结果相符. 关键词： 负磁导率 开口谐振环 透射率     

Formation of a high hydrophilic/hydrophobic contrast surface on PET substrates by ECR generated sulfur hexafluoride plasma

High hydrophilic/hydrophobic contrast surfaces on polyethylene terephthalate (PET) substrates were formed by shadow mask technique in electron cyclotron resonance generated sulfur hexafluoride plasma atmosphere. The X-ray photoelectron spectroscopy (XPS) analyses indicate that the unmasked PET surfaces contained a high proportion of the CF₂-CF₂ groups, and therefore were hydrophobic with large water contact angle. However, the surface wettability was found to increase drastically on the masked PET surfaces. This could be resulted from a mass of COF (acid fluoride) compounds observed by XPS on the masked film surfaces. The COF compounds could react with atmospheric moisture to form -COOH groups, which in turn increased the surface wettability. In addition, the surface wetting property of the masked areas was found to change significantly with the plasma treatment time, the mask-to-substrate distance and the storage time after the treatment. The best contract in water contact angle obtained from the treated PET samples was larger than 100° after 168 h of storage.     

Multi-exciton spectroscopy on a self-assembled InGaAs/GaAs quantum dot

We report about spatially resolved magneto-optical experiments on a self-assembled InGaAs quantum dot. Using electron beam lithograpy for patterning a metal shadow mask we can isolate a single dot. This allows us to study the optical response of a single dot as a function of excitation power and magnetic field. We investigate the influence of many body interaction in the emission spectra for different exciton occupation numbers of the dot. The diamagnetic/orbital shift as well as Zeeman splitting in a magnetic field can be fully resolved and are used to identify the observed emission lines. Further we report on absorption properties of the quantum dot as a function of magnetic field. We analyse in detail the phonon-assisted absorption process connected with the GaAs LO-phonon 36 meV above the single-exciton ground state.