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[en] Spin coating of multicomponent precursor solutions was employed in conjunction with block copolymer nanotemplates to fabricate nanopatterned functional multielemental materials. Nanodot and nanowire arrays of several multielemental materials exhibiting optoelectronic and multiferroic properties have been fabricated on various substrates to demonstrate the versatility of our approach. The shape, size and density of nanopatterned multielemental materials can be tuned in a variety of ways. This low cost and large scale solution nanopatterning process without a harsh etching step may offer a new opportunity for development of ultrahigh density device nanostructures.
[en] This paper reports nanoindentation examination of 600 nm thin carbon-doped low-k films spin-coated on silicon wafer. Our results confirm the recently discovered [R.J. Nay, O.L. Warren, D. Yang, T.J. Wyrobek, Microelectron. Eng. 75 (2004) 103] advantages of using sharp cube-corner indenter instead of conventional Berkovich pyramid for low-k films testing. We were able to detect three-layer structure of investigated films and to compare their relative characteristics using exclusively the registered nanoindentation data. This contrasts the previous works that concluded the existence of cap-layer from the microscopic inspection of the indentation impression. The pop-in behaviour is confirmed to be associated with fracture of the low-k film, while the details of the responsible mechanism remain undetermined at the present level of the knowledge in the field
[en] The development of micro lens arrays has garnered much interest due to increased demand of miniaturized systems. Traditional methods for manufacturing micro lens arrays have several shortcomings. For example, they require expensive facilities and long lead time, and traditional lens materials (i.e. glass) are typically heavy, costly and difficult to manufacture. In this paper, we explore a method for manufacturing a polydimethylsiloxane (PDMS) micro lens array using a simple spin coating technique. The micro lens array, formed under an interfacial tension dominated system, and the influence of material properties and process parameters on the fabricated lens shape are examined. The lenses fabricated using this method show comparable optical properties—including surface finish and image quality—with a reduced cost and manufacturing lead time. (paper)
[en] We developed and characterized a new laser bonding process with a nano adhesive layer for transparent materials. The adhesive is spin-coated on a glass substrate and cured locally with a focused laser beam. The minimum viscosity of the adhesive is very low, so that a thin layer only a few hundred nanometers thick can be coated on a cover substrate. Laser irradiation from a Nd:YAG laser system with a wavelength of 1064 nm is employed as the curing source for the localized nano layer bonding process. The measured thickness of the bonding layer is in the range of 400 nm to 3 μm. This process can be applied to the nano or micro bonding of various transparent systems such as flat panel displays, biochips, and heat-sensitive microelectronics. We present experimental results and discuss the process characteristics
[en] This paper reports a simple and scalable spin-coating technique for assembling 70 nm silica nanoparticles into non-close-packed colloidal crystals over a large area. The thickness of the shear-aligned colloidal crystals can be controlled from hundreds of layers to a single monolayer by adjusting the spin-coating conditions. We further demonstrate that the spin-coated colloidal monolayers can be used as structural templates to pattern sub-100 nm pillar arrays directly on silicon substrates. The resulting subwavelength-structured pillar arrays exhibit excellent broadband antireflective and superhydrophobic properties, which are promising for developing self-cleaning antireflection coatings for crystalline silicon solar cells. This bottom-up approach enables large-scale production of periodic nanostructures with resolution beyond the optical diffraction limit that have important technological applications ranging from high-density data storage and optoelectronics to biological sensing and subwavelength optics.
[en] In the present study, the potential of poly(ether imide) as corrosion protective coating for magnesium alloys was evaluated using the spin coating technique. The influence of different parameters on the coating properties was evaluated and the corrosion behaviour of the coatings was investigated using electrochemical impedance spectroscopy. The best corrosion protection was obtained preparing the coatings under N2 atmosphere, using 15 wt.% solution in N'N'-dimethylacetamide (DMAc) which resulted in a coating of approximately 2 μm thickness, with an initial impedance of 109 Ω cm2 and of 105 Ω cm2 after 240 h of exposure to a 3.5% NaCl solution.
[en] Strontium and calcium - modified lead titanate (Pb0.7 Ca0.15 Sr0.15 ) TiO3 (PCST)thin films were prepared by using spin coating technique. Phase transition of PCST was interpreted by means of Er-T characteristics. Process temperature dependence on micro-structure of PCST film was studied. Charge conduction mechanism of PCST thin film was also investigated for film qualification.
[en] Single-walled carbon nanotubes (CNTs) and double-walled CNTs with a selectivity of 93 % were obtained by means of the novel homemade iron catalysts which were spin coated on silicon wafer. The average diameters of the iron particles prepared from the colloidal solutions containing 30, 40, 50, 60, and 70 mmol/L of iron nitrate were 8.2, 5.1, 20.8, 32.2, and 34.7 nm, respectively, and growing thin-walled CNTs with the average diameters of 4.1, 2.2, 9.2, 11.1, and 18.1 nm, respectively. The diameters of the CNTs were correlated with the geometric sizes of the pre-growth catalyst particles. Thin-walled CNTs were found to have a catalyst mean diameter-to-CNT average diameter ratio of 2.31. Iron carbide was formed after the growth of CNTs, and it is believed that during the growth of CNTs, carbon source decomposed and deposited on the surface of catalyst, followed by the diffusion of surface carbon into the iron catalyst particles, resulting in carbon supersaturation state before the growth of CNTs.
[en] Large-area, close-packed, monolayer colloidal crystals can be used as templates in the preparation of micro/nano films. This work proposes a hybrid method of spin coating and peeling–draining for the production of large-area, close-packed, monolayer colloidal crystals. First, large-area monolayer polystyrene (PS) colloidal crystals were obtained through spin coating. Then, the colloidal crystal film was peeled from surface of the intermediate spin-coated silicon wafer and transferred to another substrate using a customized experimental device. Oxygen plasma treatment was utilized to modify the wettability of the silicon wafer, increase the uniformity of spin coating, and reduce the adhesion work of peeling. The key process parameters, such as the duration of oxygen plasma treatment, spin speed, peeling speed, and drop rate of water surface, of the proposed method were thoroughly analyzed and optimized. Three-inch, wafer-scale, large-area, close-packed monolayer colloidal crystals were obtained using the proposed method, which combines the advantages of spin coating and gas-liquid interface self-assembly and offers a stable and controllable approach to the fabrication of monolayer PS colloidal crystals. - Highlights: • A hybrid method of spin coating and peeling-draining was proposed. • Three-inch high quality close-packed monolayer colloidal crystals were acquired. • Spin speed, peeling speed and draining rate were thoroughly analyzed and optimized.
[en] The effects of the solvent on in-plane stress evolution were studied on sol-gel-derived silica gel coatings during heating. Si(OC2H5)4-H2O-HNO3-ROH (ROH = CH3OH, C2H5OH, n-C3H7OH, and n-C4H9OH) solutions were prepared where the mole ratio Si(OC2H5)4:H2O:HNO3 = 1:8:0.01 and the volume ratio Si(OC2H5)4:ROH = 1:1.1. Silica gel films were deposited by spin coating on Si (100) wafers 4 in. in diameter, and heated at 5 deg. C /min up to 500 deg. C , where in situ stress measurement was conducted by measuring the substrate curvature. The stress was tensile and increased with increasing temperature. The stress was found to be identical below 200 deg. C between the films prepared with different alcohols while the stress above 200 deg. C was larger in the order, n-C4H9OH < n-C3H7OH ∼ C2H5OH < CH3OH, namely in the order of the boiling points of the solvents