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We have investigated the relation among ρ – T characteristics, superconductivity, annealing conditions and the crystallinity of polycrystalline (In 2 O 3 ) 1− x –(ZnO) x films. We annealed as-grown amorphous films in air by changing annealing temperature and time. It is found that the films annealed at 200 °C or 300 °C for a time over 0.5 h shows the superconductivity. Transition temperature T c and the carrier density n are T c n ≈ 10 25 –10 26 m −3 , respectively. Investigations for films with x = 0.01 annealed at 200 °C have revealed that the T c , n and crystallinity depend systematically on annealing time. Further, we consider that there is a suitable annealing time for sharp resistive transition because the transition width becomes wider with longer annealing times. We studied the upper critical magnetic field H c2 ( T ) for the film with different annealing time. From the slope of dH c2 / dT for all films, we have obtained the resistivity ρ dependence of the coherence length ξ (0) at T = 0 K.

A micro-beam NRA system, by means of a resonant nuclear reaction 1H(15N, αγ)12C, has been developed for the purpose of the 3D mapping of the hydrogen distribution in solids. To obtain the tens μm size of the beam spot, the combination of the newly proposed tapered glass capillary and a conventional quadrupole magnetic lens is employed. An Y patterned film on a substrate is prepared as an application of the developed system. The 6 MeV 15N beam focused by glass capillaries down to 50 μm successfully shows the hydrogen distribution. The in-plane NRA profile implies that the beam emitted from the glass capillary outlet is parallel, although the original beam has a considerable divergence. The NRA measurements in the 103 Pa N2 atmosphere due to the low gas conductance of the glass capillary is also demonstrated.

To improve overcoat films for giant magnetoresistive (GMR) heads, we developed a commercial multi-film deposition system capable of performing three diamond-like carbon (DLC) deposition methods, i.e. electron cyclotron resonance-chemical vapor deposition (ECR-CVD), ion beam deposition (IBD), and filtered cathodic vacuum arc (FCVA); pre-cleaning with Ar sputtering etch; and Si adhesion layer deposition. In comparative evaluations of 50-nm-thick films deposited on a Si wafer, ta-C film by FCVA shows higher hardness/density compared to DLC films by ECR-CVD or IBD. Scratch testing and electron spectroscopy for chemical analysis (ESCA) measurements of films prepared by ECR-CVD and FCVA on an Al 2 O 3 TiC substrate indicate that substrate bias enhances mixing between the carbon film and either the Si film or Al 2 O 3 TiC substrate such that good adhesion occurs.

We performed direct measurement of hydrogen content in diamond-like carbon (DLC) thin films using elastic recoil detection analysis (ERDA) of hydrogen atoms forward-scattered by a 2 keV beam of helium ions. DLC films were prepared in an electron cyclotron resonance (ECR) microwave plasma chemical vapor deposition (CVD) system. Use of a low-energy beam in conjunction with a small incidence angle allowed measurements of hydrogen content in the surface region of films of various thickness (2.4, 5 and 100 nm). Analysis of resultant spectra indicates that a higher negative substrate bias voltage produces lower hydrogen content; these findings are consistent with those obtained on thick DLC films using high-energy (2–3 MeV) ERDA. Accordingly, this confirms the suitability of using the low-energy ERDA system described to measure hydrogen content in ultrathin (

In order to obtain 3D mapping of the hydrogen distribution in solids in-situ, the nuclear reaction analysis (NRA) measurement has been carried out by using a tapered glass capillary to focus and introduce the incidence beam to the sample under atmosphere. A Y thin film covered with Pd was used for this measurement. In the N2 gas, hydrogen absorbed by the Y film was observed at a pressure up to 8×103 Pa. In the H2 gas and air, on the other hand, substantial γ-ray signals were observed at 15N energies of 6400~7200 keV, which obscured the signal originating from the Y sample. The origin of this signal is discussed.

Molecules being adsorbed on the surface dramatically change the physics and the chemistry of the substrate, thus offering an opportunity for precise sensing of the molecules via monitoring the transformation of the state of the adsorbent. Combination of different types of substrates, forming the surface interface border, generally exhibits synergistic effect dramatically enhancing sensitivity factor. In this regard, the aim of the present work is to demonstrate how the metal/oxide interface, formed in-vacuo (10-10 Torr) by deposition of metal nanoclusters on oxide support, affects behavior of NO and CO molecules being adsorbed on the surface. Coadsorption of NO and CO molecules on the Ni clusters deposited on MgO(111) film formed on Mo(110) crystal has been studied by reflection-absorption infrared spectroscopy (RAIRS) and temperature programmed desorption (TPD). Observed high sensitivity of metal/oxide interface to the molecular behaviour suggests an opportunity for design of new molecular sensors based on the metal/oxide nanostructures.

Azo-type nonmesogenic monomer and mesogenic monomers which tend to be arranged in homogeneous or in homeotropic alignment were synthesized. Copolymers were obtained using these monomers by radical polymerization. Thermal and nonlinear optical properties of these copolymers were investigated. The second order nonlinear optical susceptibility enhancement due to liquid crystalline orientation has been observed.

Here we report a novel reactive sputtering method, called two-stage high rate reactive sputtering method, its principles, and apparatus setup, and the results of optical properties of thin films obtained by this method. Then two typical antireflection coatings, one with an intermediate and homogeneous layer and the other with a gradient layer, have been successfully produced by this method. Their spectrum performances and microstructures are also presented.

The bio probe is expected to measure electrical and physical information of cells. This paper presents novel bio probe device in order to improve efficiency of extra and intra cellular measurement. The device consists of a needle type probe integrated with a novel operating mechanism. The operating mechanism allows self-alignment between a probe and a cramped cell. The self-alignment mechanism can reduce difficulties in manipulating instruments such as a glass capillary in conventional methods. MEMS technology can provide distributed bio probe devices in batch. Design and fabrication of proposed device are followed by experimental results with P19 embryonal carcinoma cells.

Effects of micro-gap electrode on dilute Cl/sub 2/ gas sensing properties have been investigated for the In/sub 2/O/sub 3/thin film microsensors. The micro-gap electrodes with various gap size (0.1-2 /spl mu/m ) were fabricated on SiO/sub 2//Si substrate by means of MEMS techniques (photolithography and FIB). Then the In/sub 2/O/sub 3/ thin film was deposited on the electrode to be micro gas sensor. The resistance of In/sub 2/O/sub 3/ microsensor was increased upon exposure to dilute Cl/sub 2/ gas of ppm-level, while the sensor responded to Cl/sub 2/ gas less than 0.5 ppm with resistance decrease. Interestingly, in both cases the sensitivities were increased with decreasing gap size. The high sensitivity was obtained for In/sub 2/O/sub 3/ microsensor with 0.1 /spl mu/m gap. The behavior was explained by the large contribution of interface between electrode and oxide at small gap and the high sensitivity at interface.

Twin MONOS is a CMOS-based dual bit nitride storage flash memory technology which offers low cost, high performance and low power.

Over 65% efficiency 300MHz bandwidth C-band internally-matched GaAs FET has been developed by using a large-signal FET model. In order to achieve high efficiency in broad-band, optimum impedances at each frequency are estimated by using the large-signal FET model. The large-signal FET model is based on Angelov model. The capacitance equations of the model are improved to satisfy charge conservation. The model parameters are extracted for a unit cell FET with a small gate width. The unit cell FET model was scaled up to one chip FET model with a wide gate width, considering increase of source inductance by sharing via holes. The developed C-band internally-matched FET has achieved power-added efficiency (PAE) of over 65% across 300MHz bandwidth.

Fully overlapped lightly doped drain FOLD n-channel MOSFETs built for the purpose of improving the tradeoff between performance and reliability are discussed. Full gate overlap was achieved by using angled implants to extend LDD (lightly-doped drain) regions beneath the gate edge of devices. The dose and energy of the angled implants were varied. The parasitic overlap capacitance and series resistance as well as the reliability enhancement introduced by the FOLD structure are investigated in detail. The series resistance is shown to be strongly dependent on gate voltage, while the overlap capacitance is found to be reduced significantly by depletion of the FOLD drain regions. The corresponding reduction in hot-carrier-limited channel length more than compensates for the increase in parasitics, indicating substantial enhancement in net drive performance. >

The purpose of this work is to clarify the relation between dielectric film characteristics and stress migration (SM). It has been considered that the dielectric-deposition-temperature-induced stress, caused by the difference of the expansion coefficients for Al, is the main factor for SM. However, it was found that Al diffusion into dielectrics, Al recrystallization, and dielectrics flexibility are also significant for SM. It is shown that the best method of dielectrics formation against SM is depositing low-Al-diffusivity dielectrics at low temperature after stress relaxation. >

By disassociating from the conventional planar Nch FET structure, a new step split channel device with a new mechanism of ballistic channel hot electron (CHE) injection promises viability in future EEPROM/flash applications. The new non-planar device exhibits fast program of /spl sim/100 ns, at a maximum internal voltage of 5 V and at low currents of less than 10 /spl mu/A.

A planar channel split floating gate memory cell with an ultra short channel of

In a stack NOR flash cell, a small vertical (step) channel has been added to the conventional horizontal channel, to reduce the operating voltages for CHE injection and FN ejection. Devices and processes have been optimized based on extensive 2D simulations, with hardware results showing a 1-1.5 V reduction in the drain voltage requirement, and more than one order of magnitude increase in injection efficiency.

The effect of the surface structures on photocatalytic activity and photoexcited charge separation was studied using titanates with tunnel and non-tunnel structures. BaTi4O9 with a pentagonal prism tunnel structure, Na2Ti6O13 with a rectangular tunnel structure, and Ba4Ti13O30 with non-tunnel structure were employed as a titanate, on which RuO2 was supported by an impregnation method to prepare photocatalysts. The stoichiometric production of oxygen and hydrogen from water with irradiation by an Xe lamp occurred only for the photocatalysts with tunnel structure titanates. ESR spectra of BaTi4O9 and Na2Ti6O13 at 77 K in the presence of uv irradiation showed the characteristic peaks assigned to surface O− radicals in the presence of O2 and N2O, whereas no peak appeared for Ba4Ti13O30 under similar conditions, thus indicating that the tunnel structure titanates have high efficiency for the separation of photoexcited charges. Raman spectra showed that the TiO6 octhahedra in the tunnel structures had short Ti-O bonds which reflected large distortion of the octahedra. It is demonstrated that the distortion of TiO6 octahedra produces dipole moments nearly directed to the center of the tunnel, which is proposed to form useful electric fields for the separation of photoexcited electrons and holes without recombination.

In order to predict the performance of rolling oils in actual production mills, from tests in laboratory mills, the influence of various factors, such as shape factors work roll diameter (D), strip thickness (h1), operating conditions (reduction rate (r), peripheral velocity of roll (U0), strip velocity (U1)) and kinematic viscosity of the rolling oil (υ0) was investigated. A parameter RLI (Rolling Lubrication Index = u0(U0+U1)(1−r)(D/2h1.r)½) was found to be useful in predicting lubricating conditions in actual production mill applications. The coefficients of friction of mineral oils, some synthetic hydrocarbons including polybutene, and several kinds of additives were obtained from laboratory mills under the same condition of RLI value as that for finish rolling in actual production mills. With hydrocarbons, paraffins showed the lowest coefficient offriction, while aromatics exhibited a higher coefficient of friction, with naphthenes showing the highest. A high-quality rolling oil was formulated using a combination of ester and paraffinic mineral oil. It is observed that this new oil can save 14% of energy consumed by a laboratory mill compared with conventional rolling oils. In production mills, nearly the same energy conservation level can be achieved.

ZrO2 and Ta2O5 films were used as solid electrolyte layers in electrocnromic cells of WO3. Measurement of the weight changes of those cells during coloration and bleaching suggested that water contained in the cells played an important role for the coloration. Another kind of cell showed that it is not the water in WO3 layer but that in a solid electrolyte layer that is essential. Reasons of deterioration of the electrochromic cells are not only a peeling Au electrode off from the cells but also a kind of morphologic changes of films.

The LDD structure, where narrow, self-aligned n/sup -/ regions are introduced between the channel and the n/sup +/ source-drain diffusions of an IGFET to spread the high field at the drain pinchoff region and thus reduce the maximum field intensity, is analyzed. The design is shown, including optimization of then- dimensions and concentrations and the boron channel doping profile and an evaluation of the effect of the series resistance of the n- regions on device transconductance. Characteristics of experimental devices are presented and compared to those of conventional IGFET's. It is shown that significant improvements in breakdown voltages, hot-electron effects, and short-channel threshold effects can be achieved allowing operation at higher voltage, e.g., 8.5 versus 5 V, with shorter source-drain spacings, e.g., 1.2 versus 1.5 /spl mu/m. Alternatively, a shorter channel length could be used for a given supply voltage. Performance projections are shown which predict 1.7 X basic device/circuit speed enhancement over conventional structures. Due to the higher voltages and higher frequency operation, the higher performance results in an increase in power which must be considered in a practical design.

A deeper understanding of water sorption phenomena in MgF 2 films has been acquired by investigation of the substrate temperature dependence of the packing densities and the dynamic change in water sorption in the pores of the films through various subsequent treatments. As a result, 10% of the total volume of the films, or 32.0–35.7% of the total pores, has been shown to be already occupied by water molecules before the films are exposed to air. When this effect was taken into account the true value of the packing density of MgF 2 films deposited onto unheated substrates was found to be 0.72–0.75.

The inhomogeneity of the refractive index in optical thin films has often been represented by an assembly of two homogeneous layers, one usually being rather thinner than the other and with a refractive index further removed from that of the ideal single layer. In this present study the inhomogeneity is related more directly to the physical structure of the layers and especially to the form of their columnar grains. In order to derive the optical properties of a columnar solid, techniques for the calculation of the refractive index of arrays of columns are necessary, and a number of possible techniques are compared. The inhomogeneity in films of zinc sulphide, cryolite and titanium dioxide is interpreted in terms of the columnar model of film structure and its relationship with other aspects, such as packing density, is examined.

Thin film heteroepitaxial silicon and GaAs grown on sapphire (Al2O3) were studied in an MIS configuration using a photoelectric technique. The Al2O3 substrate layer serves as the insulator and an aluminum film deposited on the other side of the substrate serves as the metal electrode. The results demonstrate that it is possible to transport photoexcited electrons across Al2O3 layers of several mils thickness. The photoelectric threshold energy value for the Al–Al2O3 is measured to be 3.85±0.05 eV while for the Si–Al2O3 and GaAs–Al2O3 interfaces, the values of the threshold energy are 4.5 and 4.4 eV, respectively. The electron affinity of the sapphire is found to be 0.42±0.07 eV. The amount of band bending in the semiconductor is obtained from the experimental results. It is also shown that the escape length of photoelectrons in heteroepitaxial semiconductor films is at least several microns in contrast with the low values (of the order of a few angstroms) quoted in the literature for bulk materials.

Photoemission from solids into a vacuum has hitherto been used in the study of the band structure of solids. Photoemission from one solid into another can also be used to study the band structure. Photoelectric emission from silicon into oxide in a metal-oxide-semiconductor (MOS) geometry is used in this paper for the study of the band structure of silicon. The photoelectric threshold energy is reduced by bias heat treatment of the MOS structure, analogous to the cesiation of the silicon surface, to reduce the work function in vacuum emission studies. In the region below 5.8 eV, we observe four peaks at 3.5, 4.2, 5.0, and 5.7 eV. These results are compared with those observed by Gobeli and Allen in vacuum-emission studies and with the theoretical calculation of Brust. It is concluded that the photoelectric investigation using a MOS geometry is a convenient tool for the study of the band structure of semiconductors.

It is shown that it is possible to measure directly, using a photoelectric technique, the built‐in voltage in a MOS structure. The experimentally measured values, using this method, are compared with values obtained by another method, and the validity of this method is established.

The growth of oxide layers on silicon is frequently carried out during the fabrication of integrated circuits. This paper describes the results of the study of the oxide layer and the Si-SiO 2 interface in a MOS configuration, by a photoelectric technique. The interface barrier height and the built-in voltage V MS in the oxide layer of a MOS structure are measured. The effect of ion migration has been studied by subjecting the structure to bias-heat (BH) treatment. We have constructed the band energy diagram for a p-type 0.001 Ω ċ cm MOS structure, both before and after BH treatment. The photoelectric technique is found to be a convenient tool to study and compare different oxidation processes.

Dense Z‐pinch plasmas are created by two different ways and are examined experimentally. A stable plasma column existing for about 20 ns has been created in the carbon fiber pinch driven by a pulsed power generator. Any significant differences in emitted soft X‐ray intensity from the plasma are not observed between fiber pinches of carbon fiber with nickel or copper coating and without any coating material. Techninal difficulties in handling thin foil metal liner for linear compression experiments are overcome by proposing a conductive thin film deposited on the surface of discharge tube wall as a compression liner. Uniform cyclindrical compression of the thin film liner has been confirmed.

SUMMARY Agreement was obtained between numerical and experimental results for 45°, 60°, and 70° incidence on an inclined cracks of 1.5 mm depth. From the vectors diagrams, two kinds of waves, crack tip wave and corner waves are distinguished, and a new technique to determine crack sizes is proposed.

Several approaches using ultrasonic (UT) waves to study changes in intracranial pressure (ICP) have been previously reported. However, the studies were not successful in obtaining information throughout the range of the pathological variations in ICP levels (Oka et al. 1971). Additionally, operative procedures were necessary to open a hole in the skull (Itoh et al. 1986) or to install a spring coil (Numoto et al. 1983). The aim of our study was to procure noninvasively continuous wave forms and levels of ICP by using a UT probe on the scalp. The following is a report of experimental results including some clinical examples with our method.