Good Surface Smoothness Research Articles

Nanocrystalline Diamond Films Deposited by the Hot Cathode Direct Current Plasma Chemical Vapor Deposition Method with Different Compositions of CH4/Ar/H2 Gas Mixture

Nanocrystalline diamond films with different grain sizes were synthesized on Si substrate by the hot cathode direct current plasma chemical vapor deposition method with different compositions of CH4/Ar/H2 gas mixture. The morphology and microstructure of the obtained products were characterized by scanning electron microscopy, atomic force microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. The results showed that the composition of the CH4/Ar/H2 gas mixture affected greatly the grain sizes, surface smoothness, and crystal quality of the nanocrystalline diamond films. With the increase of CH4 concentration, the grain sizes got smaller and the surface of the films got smoother. However, the grain sizes got smaller and the crystal quality was weakened with the increase of Ar concentration. In the process of deposition, SiC was formed at the substrate before the growth of nanocrystalline diamond films, which increased the secondary nucleation of nanocrystalline diamonds. To obtain the nanocrystalline diamond films with uniform small grain sizes, good surface smoothness, and little non-diamond phase, the optimal composition of the CH4/Ar/H2 gas mixture is 6/70/30 and 7/70/30.

Photocurable Organic Gate Insulator for the Fabrication of High‐Field Effect Mobility Organic Transistors by Low Temperature and Solution Processing

A new organic gate insulator in OTFT devices, which satisfies the requirements for the fabrication of a practical TFT array, such as a good chemical resistance, a low moisture uptake, a low temperature process, and a good film surface smoothness, is introduced. Since this gate insulator film is formed by photo-curing after spincasting on the top of the gate electrode, the process does not require high temperatures.

Sequential Changes in Implanted Cartilage After Autologous Osteochondral Transplantation: Postoperative Acoustic Properties up to 1 Year in an In Vivo Rabbit Model

For successful autologous osteochondral transplantation, it is important that the cartilage in an implanted plug provide histologic replacement of damaged cartilage with cartilage that is structurally and mechanically normal. The purpose of this study was to investigate whether the press-fit technique reconstructs the normal hyaline cartilage and provides acoustic stiffness equal to that of normal intact cartilage. In 36 rabbits an osteochondral plug, 6 mm in diameter, was removed from the right patellar groove and grafted into a recipient hole, 5 mm in diameter, in the left patellar groove. Specimens at 2, 4, 8, 12, 24, and 52 weeks postoperatively were assessed by macroscopic and histologic observation and by use of an ultrasonic system. The ultrasonic acoustic stiffness, acoustic surface irregularity, and acoustic thickness of the implanted cartilage were examined and compared with normal intact cartilage. The gross appearance of the implanted cartilage was glossy, maintained good surface smoothness, and survived well throughout the observation period. The cartilage recovered histologic features of hyaline cartilage. The acoustic stiffness decreased up to 12 weeks and then increased at 24 and 52 weeks after surgery. The acoustic stiffness at 8 or 12 weeks was significantly lower (acoustically softer) than that of control cartilage (P < .001). The acoustic stiffness at 52 weeks was equal to that of the control. The difference in acoustic surface irregularity was not significant. The acoustic thickness at 8 weeks was higher (acoustically thicker) than that of the control (P < .01). Although the reason acoustically soft cartilage in plugs becomes acoustically stiff and whether the histology of the implanted cartilage had recovered completely remain unclear, the acoustic stiffness recovered to normal control values by 52 weeks postoperatively. Postoperative care for up to 12 weeks should be taken after autologous osteochondral transplantation.

The effect of substrate temperature on the properties of ITO thin films for OLED applications

Indium tin oxide (ITO) thin films have been deposited by rf magnetron sputtering on glass substrates at different substrate temperatures. The structural, electrical and optical properties of these films have been investigated to obtain optimum values for resistivity, optical transmittance and surface smoothness. The film deposited at a substrate temperature of 300 °C shows good conductivity, optical transmittance, crystallinity and surface smoothness. These ITO films were used to fabricate organic light emitting diodes (OLEDs). The dc current–voltage (I–V) studies on ITO/PEDOT:PSS/MEH-PPV/Al test structures show better rectifying behaviour on a smoother ITO substrate.

Synthesis of a New Cross-Linkable Perfluorocyclobutane-Based Hole-Transport Material

[reaction: see text] A new curable arylamine containing a perfluorocyclobutane (PFCB) structure without an acidic group was synthesized. The material was thermally cured on ITO after spin-coating. The polymer showed excellent solvent resistance, high thermal stability, high transparency, and good surface smoothness.

Characterization of crystalline Pb 0.92La 0.08Zr 0.4Ti 0.6O 3 thin films grown by off-axis radio frequency magnetron sputtering

In this study, we examine the growth conditions for Pb 0.92La 0.08Zr 0.4Ti 0.6O 3 thin films with a linear electro-optical response. Films grown on SrTiO 3(100) substrate show good crystalline quality and surface smoothness, if deposited within a narrow range of substrate temperatures around 530 °C. Such films had a (002) rocking curve full width at half maximum less than 0.2°, and a surface roughness less than 0.4 nm. X-ray photoelectron spectroscopy analysis confirmed the absence of surface impurity phases and revealed a single oxidation state for Pb 2+, Zr 4+, and Ti 4+cations. Good crystalline quality and a smooth film surface are required for the use of these materials in optical device applications.

Nb/AlOx–Al/Nb Josephson junction fabricated using facing target sputtering system

Nb and Al films have been deposited under the high-density plasma using facing target sputtering applied with DC power. An SiO2 film has been also deposited using facing target sputtering applied with RF power. We have obtained an damage-less SiO2 film with good surface smoothness and uniformity under the high deposition rate condition. Fabricated Nb/AlOx–Al/Nb junction indicated the I–V characteristics with small sub-gap leakage current in spite of having no a substrate water-cooled mechanism in the sputtering system. We think it is effective for the facing target sputtering technique to obtain the junction with small sub-gap leakage current, because the γ electrons generated in the plasma are retained and reciprocated between a pair of targets and those hardly do damage to the junction interface during the deposition.

Surface Smoothness of Glass Mat Reinforced Polypropylene Stampable Sheet

Stampable sheets can be made consisting of polypropylene (PP) plies and long glass fibre mat plies. Because stampable sheet is recyclable, and it shows good mechanical properties and processability, it is used for automotive products. However, products made of stampable sheet do not have sufficient surface smoothness, so they are not used for exterior parts that require high surface quality. In this study, the moulding conditions needed for good surface smoothness was investigated. The results indicated that surface smoothness is affected by mould temperature. When the mould temperature was near the melting temperature of the resin, the products had high surface smoothness, but this condition was not appropriate for mass production because it lengthened the production cycle too much Finally, we proposed suitable moulding conditions.

Fabrication of YBCO thick films on Nd 2CuO 4 buffered Ni tapes by liquid phase epitaxy

REBa 2Cu 3O 7− δ (RE=rare earth, REBCO) thick films with T cs of 91 K and J cs over 1 MA/cm 2 have successfully been grown on single crystal substrates by liquid phase epitaxy (LPE), with a fast growth rate of 1 μm/min. However, the growth of REBCO thick films on metallic substrate is much more difficult. There is an urgent need to find a suitable metallic substrate and its buffer layers, which can meet the special conditions of the LPE growth. We have developed a new buffer, Nd 2CuO 4, on surface oxidised Ni tape by a number of liquid-phase processing methods. The Nd 2CuO 4 buffer layers grown from liquid phase had excellent biaxial texture and a good surface smoothness suitable for subsequent REBCO growth. LPE growth of YBCO on such Nd 2CuO 4/NiO/Ni substrates showed that dense nucleation of YBCO on Nd 2CuO 4 was possible without any REBCO seed layer and there was little reaction between the Nd 2CuO 4 buffer and the high-temperature CuO:BaO solution.

Novel Candidate of c-axis-oriented BLSF Thin Films for High-Capacitance Condenser

ABSTRACTc-axis-oriented SrBi2Ta2O9 thin films with various thickness ranging from 20–170 nm were epitaxially grown on (100)SrRuO3 (SrRuO3 is give for the pseudo-cubic unit cell)//(100)SrTiO3 substrates by metalorganic chemical vapor deposition (MOCVD). The relative dielectric constants of these films kept a constant value of about 55 with decreasing film thickness down to 20 nm. The capacitances of these films were almost independent of the applied electric field; change of capacitance for these films on applied electric field from 0 kV/cm to 100 kV/cm was within 0.017 % and tano value was within 1.3 %. The leakage current densities were constant against the film thickness on the order of 10-8 A/cm2 at 150 kV/cm. Surface flatness of these films were also almost the same irrespective of the film thickness. These characteristics are very attractive for high-capacitance condenser application. Therefore, c-axis-oriented BLSF thin films are novel candidates for high-capacitance condenser application having both bias-free and thickness independent characteristics together with the good surface smoothness.

SiO2 Insulation Layer Fabricated using RF Magnetron Facing Target Sputtering and Conventional RF Magnetron Sputtering

We have investigated the deposition conditions for a SiO2 insulation layer, such as the substrate-target length, Ar pressure and applied RF power density, using both RF magnetron facing target sputtering and the conventional RF sputtering techniques. We have fabricated an SiO2 layer having with a good surface smoothness under the high deposition rate condition using the RF magnetron facing target sputtering technique.

反応性ポリマーによるカーボンブラック粒子のグラフト化および生成粒子の特性

Carbon black powders were grafted with a polymer by using a reactive polymer, and their characteristics were examined. First, a reactive polymer, which easily reacted with the carbon black particles, was prepared. Then, the graft reaction of the carbon black with the polymer was carried out. The polymer-grafted carbon black showed high dispersibility in both the dispersion solutions and the coated layers. The former and latter were suggested from small particle size of the carbon black and high gross value, respectively. The low viscosity of the polymer-grafted carbon black solution suggested its high stability. Spin-coated layers of the polymer-grafted carbon black had a good surface smoothness. The polymer-grafted carbon black dispersed binder layer showed smooth change in electrical resistivities with the carbon black concentration. It can be concluded that grafting carbon black particles with a reactive polymer improves their dispersibility and stability.

Single-Crystal Epitaxial Thin Films of the Isotropic Metallic Oxides Sr 1– x Ca x RuO 3 (0 ≤ × ≤ 1)

Single-crystal epitaxial thin films of the isotropic metallic oxides Sr 1– x Ca x RuO 3 (0 ≤ x ≤ 1) were grown on miscut SrTiO 3 (100) substrates in situ by 90° off-axis sputtering. These thin films exhibit low isotropic resistivities, excellent chemical and thermal stability, good surface smoothness, and high crystalline quality. Furthermore, the lattice parameters and magnetic properties can be varied by simply changing the strontium/calcium ratio. These epitaxial thin films, and their multilayer structures with other oxide materials, can be used for the fabrication of superconducting, ferroelectric, magneto-optic, and electro-optic devices.

Cylindrical mandrel drawing of tubes: A matrix method simulation compared with experiment

The demand from industry for metal-forming simulation models has increased during the last ten years. Such models are found to be valuable tools considering process optimization and the development of new processes. The application of simulation models makes it possible to reduce the number of time-consuming experiments. The present work concentrates on the cylindrical mandrel drawing of tubes. If the total reduction is small, i.e., if not more than one drawing pass is necessary, this process is characterized by high productivity: compared to pilger rolling the process has been estimated to be about eight times faster. Tubes which have been manufactured by means of cylindrical mandrel drawing are distinguished by close tolerance and good surface smoothness. The tubes are often delivered in the cold-drawn, strain-hardened condition, i.e., without a subsequent annealing. Because the customer often orders a product of minimum yield stress, it is of great importance to be able to predict the strains of the tube material. The theoretical part of this study comprises the development of a simulation model based on the matrix method, the model being utilized for prediction of strains. In the experimental part a high precision investigation considering one workpiece is presented. This sample was furnished with a square network in the axial plane of symmetry. Strain distributions from theory and experiment are found to be in good agreement.

The effect of coercivity on short wavelength output for barium ferrite particulate tapes

Five barium ferrite tapes were prepared from pigments similar except for coercivity (H/sub c/). These tapes had their greatest squareness ratio in the longitudinal direction. The short wavelength output was measured on two different systems. With barium ferrite particles of 0.05- mu m diameter it is possible to make tape with a longitudinal squareness ratio of 0.68 and good surface smoothness. On an experimental test apparatus (a drum tester) the output was the same for all tapes, similar to the results reported by M. Isshiki et al. (1985). However, on an 8-mm video system the peak output increased as the pigment coercivity increased from 625 to 1100 Oe.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Reactive synthesis of well-oriented zinc-oxide films by means of the facing targets sputtering method

Well-oriented ZnO films are reactively synthesized by means of the facing targets sputtering (FTS) method. In this paper, the change in the crystallographic characteristics of ZnO films with respect to sputtering conditions are described in detail. Films obtained by means of the FTS method exhibit one of the best c-axis orientations reported to date. The following conditions are necessary for formation of well-oriented ZnO films with good surface smoothness: (1) High-energy particle bombardment on the film surface during deposition should be suppressed and (2) the sputtered particles landing on the substrate surface should have an appropriate energy level of several eV.

Bi-substituted garnet films crystallized during RF sputtering for M-O memory

We have successfully got Bi-substituted garnet films on glass substrates by in situ sputter growth above 500°C. When sputter-crystallized just above 500°C, the films had a good surface smoothness and a high crystallographic quality as compared to the post-annealed Film. The films had a preferred crystal orientation of

High rate preparation of C‐axis oriented aln films by reactive sputtering

AbstractHighly oriented AlN film has been formed at a high rate of a Targets Facing Type Sputtering (TFTS) method which has reduced substrate bombardment by various high energy particles. The relation between its crystal structure and the formation condition has been studied in detail. As a result, C‐axis oriented AlN film can be obtained for a wide nitrogen gas pressure range of 0.2 ‐ 10 mtorr at a relative low substrate temperature of around 400°C. In particular, at a low pressure of 0.5 ‐ 2 mtorr, C‐axis oriented film with good surface smoothness can be formed. Also, higher film deposition rate results in improved film orientation, and a good orientation with ΔO50 of 1.9° (σ002 of 0.9°) can be obtained at a rate of 0.6 μm/h even for a thin film of 0.2 μm thickness. Furthermore, it has been found that the orientation degrades with bias application to the substrate, and that a high‐orientation AlN film can be obtained by the TFTS method because of the suppression of substrate bombardment by high‐energy particles. From the forementioned results, to obtain a good quality C‐axis oriented AlN film with good orientation and surface smoothness, the necessity of using a sputtering method, such as the TFTS method, has been shown. In this case, particles with sufficient energy to destroy the film do not bombard the substrate, and sputtering particles themselves reach the substrate with an appropriate energy (several eV).

Crystallization of Silicon on Electro-Optic Plzt by a Laser Beam Modulated in Shape and Intensity Profile

AbstractPLZT, a ferroelectric material with a high quadratic electro-optic coefficient, is combined with silicon technology via chemical vapor deposition to enable the realization of Si/PLZT spatial light modulators. Laser crystallization is required to produce device quality silicon deposited on PLZT. The critical issues in the laser crystallization are (i) achieving crystallization in the absence of a good seed, and (ii) preventing damage to the PLZT. To prevent PLZT damage during the laser heating, a 3.5 μm silicon dioxide layer is used as a thermal buffer between the silicon and the PLZT and the effective scanning time is shortened to 100 μs. A double humped cw argon ion laser with a shaped beam is used to achieve successful crystallization with good surface smoothness and large grain size. This technology and devices fabricated on these samples will be discussed.

Dependence of magnetic properties of Co-Pt films on sputtering conditions

Magnetic properties, Young’s modulus, and corrosion resistance of Co-Pt films deposited by targets-facing type of sputtering (TFTS) have been investigated. The films deposited at a Ar gas pressure PAr of 2 mTorr present good surface smoothness and dense texture. The c axis of the hexagonal crystallites in the film orients normal to the film plane. The films have nearly the same value of Young’s modulus (≊17×1011 dyn/cm2) as that of the bulk Co-Pt alloy. On the other hand, the films deposited at PAr of 30 mTorr exhibit rough surface and columnar structure and do not exhibit any preferred orientation of crystallites. In addition, they have a small value of Young’s modulus (≊5×1011 dyn/cm2) and poor corrosion resistance compared with the film deposited at low PAr. They have coercive force Hc larger than 1 kOe, which is mainly caused by their porous structure. Besides, the Co-Pt films have large in-plane uniaxial magnetic anisotropy, which is caused by both dc magnetic field applied to substrate during deposition and oblique incidence of sputtered particles upon substrate.