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Plasma Etching (plasma + etching)
Kinds of Plasma Etching Selected AbstractsPolystyrene Arrays: Non-Close-Packed Crystals from Self-Assembled Polystyrene Spheres by Isotropic Plasma Etching: Adding Flexibility to Colloid Lithography (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 20 2009Mater. Hexagonally ordered arrays of non-close-packed spherical polystyrene (PS) particles are prepared by A. Plettl et al. on page 3279, and exhibit precisely controlled diameters and interparticle distances. An isotropic low-temperature plasma-etching process is applied to extended monolayers of PS colloids deposited onto hydrophilic silicon. These non-close-packed PS arrays are used as masks for the fabrication of arrays of cylindrical nanopores by reactive ion etching. [source] Non-Close-Packed Crystals from Self-Assembled Polystyrene Spheres by Isotropic Plasma Etching: Adding Flexibility to Colloid LithographyADVANCED FUNCTIONAL MATERIALS, Issue 20 2009Alfred Plettl Abstract Hexagonally ordered arrays of non-close-packed nanoscaled spherical polystyrene (PS) particles are prepared exhibiting precisely controlled diameters and interparticle distances. For this purpose, a newly developed isotropic plasma etching process is applied to extended monolayers of PS colloids (starting diameters <300,nm) deposited onto hydrophilic silicon. Accurate size, shape, and smoothness control of such particles is accomplished by etching at low temperatures (,150,°C) with small rates not usually available in standard reactive ion etching equipment. The applicability of such PS arrays as masks for subsequent pattern transfer is demonstrated by fabricating arrays of cylindrical nanopores into Si. [source] Correlation of Optical Emission and Ion Flux with GaN Etch Rate in Inductively Coupled Ar/Cl2 Plasma EtchingPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2003S.A. Rizvi Abstract The etching of GaN was investigated in an Ar/Cl2 inductively coupled plasma. Optical emission spectroscopy and an ion flux probe were used to obtain insight into the etch mechanisms during processing. Langmuir probe measurements were also used to determine the basic Ar/Cl2 plasma characteristics. Etch rates of ,500 nm/min were obtained at relatively low Cl2 fractions of ,50%. The dominant emission species observed were Ga (at 294 nm) and up to six GaCl peaks between 320 and 345 nm. Plasma characterisation and ion flux indicate etch mechanisms that depend strongly on atomic chlorine but with increasing power and at low Cl2, the significance of ion-based processes cannot be ruled out. [source] Creating Anti-Reflective Nanostructures on Polymers by Initial Layer Deposition before Plasma EtchingPLASMA PROCESSES AND POLYMERS, Issue S1 2009Irmina Wendling Abstract The generation of nanostructures by initial layer deposition and plasma etching offers a simple and cost-effective method for imparting broadband anti-reflection properties to polymer optics. In this study, we have investigated the possibility of controlling the structure growth on the cycloolefin polymer Zeonex®. It has been found that the geometry of the emerging nanostructures can be adjusted from "island-like," through "sponge-like," to "pinholes" merely by changing the thickness of the initial layer before the etching step. However, not all structure types provided a satisfactory transmittance enhancement. Only when the initial layer thickness and the etching time were matched in such a way that a certain material/air filling factor range and a sufficient structure depth were obtained could an outstanding anti-reflection effect be realized. [source] In Situ Monitoring of Silicon Plasma Etching Using a Quantum Cascade Laser Arrangement,CHEMICAL VAPOR DEPOSITION, Issue 6-7 2007D. Stancu Abstract In etch plasmas used for semiconductor processing, concentrations of the precursor gas NF3 and of the etch product SiF4 are measured online and in situ using a new diagnostic arrangement, the Q-MACS Etch system, which is based on quantum cascade laser absorption spectroscopy (QCLAS). In addition, the etch rates of SiO2 layers and of the silicon wafer are monitored including plasma-etching endpoint detection. For this purpose the Q-MACS Etch system is working as an interferometer arrangement. The experiments are performed in an industrial, dual-frequency, capacitively coupled, magnetically enhanced, reactive ion etcher (MERIE), which is a plasma reactor developed for dynamic random access memory (DRAM) technologies. In the spectral range 1028 ± 0.3 cm,1, the absorption cross-sections of SiF4 and NF3 are determined to be ,,=,(7.7 ± 0.7) × 10,18 cm2 molecule,1 and ,,=,(8.7 ± 0.8) × 10,20 cm2 molecule,1, respectively. [source] High-Performance Photoresponsive Organic Nanotransistors with Single-Layer Graphenes as Two-Dimensional ElectrodesADVANCED FUNCTIONAL MATERIALS, Issue 17 2009Yang Cao Abstract Graphene behaves as a robust semimetal with the high electrical conductivity stemming from its high-quality tight two-dimensional crystallographic lattice. It is therefore a promising electrode material. Here, a general methodology for making stable photoresponsive field effect transistors, whose device geometries are comparable to traditional macroscopic semiconducting devices at the nanometer scale, using cut graphene sheets as 2D contacts is detailed. These contacts are produced through oxidative cutting of individual 2D planar graphene by electron beam lithography and oxygen plasma etching. Nanoscale organic transistors based on graphene contacts show high-performance FET behavior with bulk-like carrier mobility, high on/off current ratio, and high reproducibility. Due to the presence of photoactive molecules, the devices display reversible changes in current when they are exposed to visible light. The calculated responsivity of the devices is found to be as high as ,8.3,A,W,1. This study forms the basis for making new types of ultrasensitive molecular devices, thus initiating broad research interest in the field of nanoscale/molecular electronics. [source] Arrays of Inorganic Nanodots and Nanowires Using Nanotemplates Based on Switchable Block Copolymer Supramolecular AssembliesADVANCED FUNCTIONAL MATERIALS, Issue 17 2009Bhanu Nandan Abstract Here, a novel and simple route to fabricate highly dense arrays of palladium nanodots and nanowires with sub-30,nm periodicity using nanoporous templates fabricated from supramolecular assemblies of a block copolymer, polystyrene- block -poly(4-vinylpyridine) (PS- b -P4VP) and a low molecular weight additive, 2-(4,-hydroxybenzeneazo) benzoic acid (HABA) is demonstrated. The palladium nanoparticles, which are directly deposited in the nanoporous templates from an aqueous solution, selectively migrate in the pores mainly due to their preferential attraction to the P4VP block covering the pore wall. The polymer template is then removed by oxygen plasma etching or pyrolysis in air resulting in palladium nanostructures whose large scale morphology mirrors that of the original template. The method adopted in this work is general and versatile so that it could easily be extended for patterning a variety of metallic materials into dot and wire arrays. [source] Graphene Shape Control by Multistage Cutting and TransferADVANCED MATERIALS, Issue 44 2009Lijie Ci Cutting graphene by a catalytic hydrogenation process can generate graphene pieces with smooth edges of atomic precision and well-defined shapes. Controlled cutting of graphene by creating graphene step edges by oxidation or plasma etching is demonstrated. A combination of cutting, transfer, and lithography is shown to allow the fabrication of isolated graphene devices with specific edge and shape control. [source] One-Step Direct-Patterning Template Utilizing Self-Assembly of POSS-Containing Block CopolymersADVANCED MATERIALS, Issue 43 2009Tomoyasu Hirai We report the self-assembly of organic-inorganic block copolymers (BCP) in thin-films by simple solvent annealing on unmodified substrates. The resulting vertically oriented lamellae and cylinders are converted to a hard silica mask by a single step highly selective oxygen plasma etching. The size of the resulting nanostructures in the case of cylinders is less than 10,nm. [source] Patterned Graphene Electrodes from Solution-Processed Graphite Oxide Films for Organic Field-Effect TransistorsADVANCED MATERIALS, Issue 34 2009Shuping Pang A replacement for gold as the hole-injecting metal in organic electronic devices is presented: patterned graphene electrodes prepared from graphite oxide sheets by oxygen plasma etching. Solution-processed organic FETs with poly(3-hexylthiophene) as the semiconductor and these graphene electrodes are shown to perform as well as or even better than devices with gold contacts. [source] Wafer-Level Patterned and Aligned Polymer Nanowire/Micro- and Nanotube Arrays on any SubstrateADVANCED MATERIALS, Issue 20 2009Jenny Ruth Morber A novel technique for fabrication of patterned and aligned polymer-nanowire/micro-and nanotube (PNW/PNT) arrays on a wafer-level substrate of any material is reported. By creating a designed pattern on a spin-coated polymer film using techniques, such as stamping or micro-tip writing, plasma etching results in the formation of aligned PNW arrays distributed according to the pattern. [source] Superficial modification in recycled PET by plasma etching for food packagingJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010S. A. Cruz Abstract An oxygen plasma treatment has been used to improve the adhesion of amorphous hydrogenated carbon (a-C:H) films onto surfaces of recycled poly(ethylene terephthalate) (PET). Modifications produced by the oxygen plasma on the PET surface in chemical bonds and morphology were investigated by X-ray photoelectron spectroscopy and atomic force microscopy, respectively. Contact angle measurements were used to study the changes in the surface wettability. Adhesion of the a-C:H film onto the PET surface was investigated by the tape test method. It was observed that the improvement in film adhesion is in good correlation with the increase in surface roughness, due to plasma etching, and with the appearance of oxygen-related functional groups at the surface. The results of this study indicate that a-C:H-coated recycled PET can be used in food packaging. The a-C:H film could be used as a functional barrier to reduce or prevent migration of contaminants from the polymer to the package content. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Construction of a polymer skeleton that is cut in half by ionizing radiationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2005Takashi Shimizu Abstract Polystyrene with a benzyl ester of carboxylic acid at the center of a polymer skeleton was synthesized by living radical polymerization. The initiator used had two functional groups for 2,2,6,6-tetramethylpiperidinoxyl (TEMPO)-mediated living radical polymerization on the benzyl and the carboxylic sides of the benzyl ester. Introduction of the benzyl ester changed the polystyrene from a crosslink type to a scission type polymer on ,-irradiation. Irradiation of the polymer resulted in a binary change of the molecular weight because of the dissociative capture of secondary electrons by the benzyl ester, as: The binary change of the molecular weight suggests that the polymer can be used as a new type of radiation resist with high sensitivity and spatial resolution to ionizing and high resistivity to plasma etching. The number of scissions per 100 eV radiation energy absorbed was 0.29, which was about one fourth of the yield of secondary electrons. The low efficiency was because of the recombination of polymer radicals generated by the dissociative electron attachment. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1068,1075, 2005 [source] Diamond kinoform hard X-ray refractive lenses: design, nanofabrication and testingJOURNAL OF SYNCHROTRON RADIATION, Issue 1 2009A. F. Isakovic Motivated by the anticipated advantageous performance of diamond kinoform refractive lenses for synchrotron X-ray radiation studies, this report focuses on progress in designing, nanofabricating and testing of their focusing performance. The method involves using lift-off and plasma etching to reproduce a planar definition of numerically determined kinoform refractive optics. Tests of the focusing action of a diamond kinoform refractive lens at the APS 8-ID-I beamline demonstrate angular control of the focal spot. [source] GaN nanorods and LED structures grown on patterned Si and AlN/Si substrates by selective area growthPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7-8 2010Shunfeng Li Abstract GaN nanorods (NRs) show promising applications in high-efficiency light emitting diodes, monolithic white light emission and optical interconnection due to their superior properties. In this work, we performed GaN nanostructures growth by pre-patterning the Si and AlN/Si substrates. The pattern was transferred to Si and AlN/Si substrates by photolithography and inductively-coupled plasma etching. GaN NRs were grown on these templates by metal-organic vapour phase epitaxy (MOVPE). GaN grown on Si pillar templates show a truncated pyramidal structure. Transmission electron microscopy measurements demonstrated clearly that the threading dislocations bend to the side facets of the GaN nanostructures and terminate. GaN growth can also be observed on the sidewalls and bottom surface between the Si pillars. A simple phenomenological model is proposed to explain the GaN nanostructure growth on Si pillar templates. Based on this model, we developed another growth method, by which we grow GaN rod structures on pre-patterned AlN/Si templates. By in-situ nitridation and decreasing of the V/III ratio, we found that GaN rods only grew on the patterned AlN/Si dots with an aspect ratio of about 1.5 - 2. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Optical cavity formation on GaN using a conventional RIE systemPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2006F. G. Kalaitzakis Abstract We report on the fabrication of mirror-like facets on GaN-based laser structures, using a conventional RIE system and photoresist AZ 5214 as the etch mask. The roughness of the etched sidewalls is below 100 nm and the slope is practically vertical. For enhanced material protection during plasma etching, we describe an alternative lithography procedure with a double photoresist layer. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Photoluminescence depth-profiling of lattice-mismatched InGaN thick film on GaN using inductively coupled plasma etchingPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2006Ji-Myon Lee Abstract Photoluminescence depth profiling of highly strained In0.1Ga0.9N and In0.15Ga0.85N epitaxial films have been studied employing an inductively coupled Cl2 plasma etching. The photoluminescence measurements showed that thick InGaN films (0.2 ,m) consist of three different structural phases; (i) an InN-rich region near the InGaN film surface, (ii) a region that was free from InN-rich phase under stress-relaxation in the middle of the film, and (iii) an InGaN/GaN interface region. In region (i), a higher wavelength peak from the InN-rich phase was dominant. After removing the surface layer of 500 Å, the PL peaks from InN-rich phases completely disappeared, suggesting that the InN-rich phase region is confined to a depth of 500 Å. In regions of (ii) and (iii), the strain-relaxation between InGaN and GaN had a significant influence on the luminescence properties of InGaN. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Creating Anti-Reflective Nanostructures on Polymers by Initial Layer Deposition before Plasma EtchingPLASMA PROCESSES AND POLYMERS, Issue S1 2009Irmina Wendling Abstract The generation of nanostructures by initial layer deposition and plasma etching offers a simple and cost-effective method for imparting broadband anti-reflection properties to polymer optics. In this study, we have investigated the possibility of controlling the structure growth on the cycloolefin polymer Zeonex®. It has been found that the geometry of the emerging nanostructures can be adjusted from "island-like," through "sponge-like," to "pinholes" merely by changing the thickness of the initial layer before the etching step. However, not all structure types provided a satisfactory transmittance enhancement. Only when the initial layer thickness and the etching time were matched in such a way that a certain material/air filling factor range and a sufficient structure depth were obtained could an outstanding anti-reflection effect be realized. [source] Reactive ion etching of dielectrics and silicon for photovoltaic applicationsPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 7 2006Prakash N. K. Deenapanray Abstract This paper investigates the reactive ion etching of SiO2, Si3N4, and Si using CHF3/O2 plasma. In particular, we have characterized the time and rf power dependence of the carrier lifetimes in n- and p-type FZ Si. The time dependence of reactive ion etching (RIE) at different rf powers provide insight into the two competing processes of damage accumulation and damage removal in the near-surface region of the Si during plasma etching. The carrier lifetime, measured using the quasi-steady-state photoconductance (QSSPC) technique, has a quadratic dependence on the rf power, which can be related to changes in the dc self-bias generated by the plasma at different rf powers. The change in carrier lifetime is similar in both n- and p-type Si of the same doping concentration. Using this fact, together with the electronic properties of defects obtained by deep level transient spectroscopy (DLTS), we have modeled the injection-dependence of the measured carrier lifetimes using the Shockley,Read,Hall model. The isochronal annealing behavior of plasma etched Si has also been studied. Copyright © 2006 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||