Amorphous silicon thin film transistors(a-Si TFTs) with a channel-etched structure were fabricated. The key technologies to realize these simple-process TFTs were 1) fabricating data lines and pixel electrodes of indium tin oxide(ITO); 2) carrying out tapered dry etching of plural layers of the a-Si and gate insulator silicon nitide; and 3) forming silicide layer to reduce the contact resistance between the phosphorousdoped a-Si and ITO. Excellent image quality, with a high contrast ratio of more than 100: 1, was obtained for video graphic array(VGA) mode TFT-LCDs using a dot inversion driving method. Furthermore, the transmission distribution was uniform with less than a 4.5% deviation on the whole display area although the ITO data line resistances were as large as 120 kΩ per line.

High-frequency capacitance-voltage (C-V) characteristics of buried-channel MOS capacitors with a structure of subquarter-micron pMOS have been measured and analyzed, emphasizing transient behavior. The C-V characteristics, including transient behavior, of buried-channel MOS capacitors that have a counter-doped p layer at the surface of n substrate are very similar to those of surface-channel MOS capacitors of n substrate if the counter-doped layer is shallow enough to be fully inverted at large positive bias. As gate voltage is decreased, equilibrium capacitance for inversion (accumulation for the counter-doped layer) reaches a minimum value and then slightly increases to saturate, which is peculiar to buried-channel capacitors. The gate voltage for minimum capacitance, which has been used to estimate the threshold voltage, changes dramatically by illumination even in room light. Net doping profiles of n-type dopant can be obtained from pulsed C-V characteristics even for buried-channel capacitors. For MOS capacitors with thinner gate oxide (5 nm), steady-state C-V curve is not an equilibrium one but a deep depletion one at room temperature. This is because holes are drained away by tunneling through the thin gate oxide.

We thought that multiple skeletons were inherent in an ordinary three-dimensional object. A thinning method is developed to extract multiple skeletons using 333 templates for boundary deletion based on the hit or miss transformation and 222 templates for checking one voxel thickness. We prepared twelve sets of deleting templates consisting of total 194 templates and 72 one voxel checking templates. One repetitive iteration using one sequential use of the template sets extracts one skeleton. Some of the skeletons thus obtained are identical; however, multiple independent skeletons are extracted by this method. These skeletons fulfill the well-recognized three conditions for a skeleton. We extracted three skeletons from the cube, two from the space shuttle model and four from the L-shaped figure by Tsao and Fu. The digital medial skeleton, which is not otherwise extracted, is extracted by comparing the multiple skeletons with the digital medial-axis-like-figure. One of our skeletons for the cude agreed with the ideal medial axis. The locations of the gravity center of the multiple skeletons are compared with that of the original shape to evaluate how uniform or non-biased skeletons are extracted. For the L-shaped figure, one of our skeletons is found to be most desirable from the medial and uniform points of view.

The MUSIC algorithm has proven to be an effective means of estimating parameters of multiple incoherent signals. Furthermore, the forward-backward (FB) spatial smoothing technique has been considered the best preprocessing method to decorrelate coherent signals. In this paper, we propose a novel preprocessing technique based upon ideas associated with the FB and adaptive spatial smoothing techniques and report on its superiority in numerical simulations.

A three-dimensional micromagnetic simulation using the Landau-Lifshitz-Gilbert equation was performed for thin-film magnetic recording media and magnetoresistive (MR) heads with soft adjacent layers (SAL). For recording media the simulation results for magnetization curves and media noise were compared with the results of experiments. Although the media model needs to be improved, the qualitative agreement between simulation results and experimental results shows that this micromagnetic simulation can be a useful tool for analyzing and predicting magnetic properties and recording characteristics. This work also showed that media noise is influenced by magnetostatic interaction, and that the decrease of the magnetostatic interaction is favorable for obtaining a high signal-to-noise ratio. For an MR head the output obtained with a nonuniform sense current distribution is similar to the output obtained with uniform sense current distribution for both low and high anisotropy fields (Hk=2 Oe and 10 Oe) SAL. With the low Hk SAL, however, the asymmetry of the output obtained for nonuniform sense current differs from the asymmetry obtained for uniform sense current; the difference is due to a magnetization vortex in a biased state in the SAL. With the high Hk SAL, the difference between the asymmetry obtained for nonuniform sense current and the one obtained for uniform sense current is not large; no vortices are found in the SAL at the biased state.

Co-Zr and Co-Zr-Ta amorphous films were prepared by the Kr sputtering method for use as the backlayers of Co-Cr perpendicular magnetic recording tape media. The effect of the addition of Ta to Co-Zr thin films was also investigated. Lower substrate temperature was required to prepare amorphous Co-Zr films with excellent soft magnetic properties. The relationships among Ta content X, magnetostriction constant λ and magnetic characteristics such as coercivity Hc and relative permeability µr were clarified. A method of evaluating λ of soft magnetic thin films deposited on polymer sheet substrate has been presented. Films with composition of (Co95.7Zr4.3) 100-X TaX at X of 10 at.% possessed sufficiency soft magnetic properties such as low Hc below 80 A/m and high µr above 600. Addition of Ta was effective in changing change the sign of λ from positive to negative. It was found that the negative magnetoelastic energy and the smaller λ caused the soft magnetism.

The magnetic properties and the structure of electroless-deposited NiFeB films were investigated in comparison with those of electrodeposited NiFe films. The electroless-deposited NiFeB film with 27at% Fe content had the lowest coercivity, H, as low as 0.5 Oe with a saturation magnetic flux density, Bs, of 1.0 T. The saturation magnetostriction, λ, and the uniaxial magnetic anisotropy, Hk, were 5.010-6 and 10 Oe, respectively, which were larger than those of the conventional, electrodeposited permalloy film. The permeability of as-deposited Ni70Fe27B3 film was 1000 at 1 MHz. In order to improve the permeability, the film was heated at 200 in a magnetic field applied in the hard-axis direction to decrease the Hk value, and the permeability became 2000 at 1 MHz. The crystal structure and grain size of NiFeB and NiFe films were investigated by XRD, THEED and TEM. Both films with low Hc had an fcc structure; the grain size of the NiFeB film was smaller than 10 nm, while that of the NiFe film was larger, approximately 20 nm. The results suggested that the electroless-deposited NiFeB film had a larger magnetic anisotropy than the electrodeposited NiFe film. Moreover, the films with Hc less than 10 Oe ded not show clear difference between their TEM bright images and THEED patterns.

A Monte Carlo method for the passage of electrons based on a single scattering model is developed. A code based on this method is operable on personal computers, and has been applied to analyze electron behavior in a layered system consisting of Ti (an accelerator window), air, cellulose triacetate (CTA) and backing material irradiated by 300 keV electrons. The energy spectra and the angular distributions of electrons on the CTA surface as well as depth distributions of energy deposition in the CTA for various backing materials have been obtained. Some of these results are compared with experiments, and show fairly good agreement.

Thickness dependence of breakdown properties in control and N2O-Oxynitrided oxides was investigated. Nitrogen atoms piled up at the Si/SiO2 interface increase charge-to-breakdown (QBD) under substrate injection conditions for oxide thickness below 10 nm, while no meaningful improvement is observed above 10 nm. This thickness dependence is explained by the fact that N2O-oxynitridation reduces oxide defects near the Si/SiO2 interface. N2O-oxynitridation of the oxides reduces the number of neutral electron traps due to the chemical reaction of oxide defect with nitrogen atoms. Electron trapping of N2O-oxynitrided oxides is significantly suppressed; the reduction of electron trapping events into neutral electron traps increases QBD under substrate injection. On the other hand, under gate injection, N2O-oxynitrided oxides show low rate of hole trapping during the initial stress period. However, in heavily injected condition, electron trapping is not suppressed, resulting in little improvement of QBD. In addition, the control and N2O-oxynitrided oxides show quite similar dependence of QBD on stress current density, which is related primarily to the carrier transport phenomena (tunneling, traveling, impact ionization and hole injection).

Plasma damage to gate oxide is studied using the test structures with various length antennas. It is shown that the plasma damage to gate oxide can be monitored quantitatively by measuring charge to breakdown (QBD). From the QBD measurements, it is confirmed that the degradation occurs in the duration of over-etching but not in the duration of main etching. The breakdown spots in gate oxide are detected by a photon emission method. The breakdown are caused by plasma damage at the LOCOS edge. A LOCOS structure plays an important role for the degradation by the plasma damage.

A new evaluation technique of hot carrier degradation is proposed and applied to practical evaluation of p-channel polycrystalline silicon thin film transistors (TFT). The proposed technique introduces emission microscopy which is particularly effective for evaluating TFT devices. We have developed an automatic measurement system in which measurement of the electrical characteristics and monitoring the photo emission are done simultaneously. Using this system, we have identified the dominant mechanism of hot carrier degradation in TFTs, and evaluated the effect of plasma hydrogenation on hot carrier degradation.

An HDTV still-picture camera that uses four PAL CCD sensors has been developed for use as a high-speed, high-resolution image reader. The CCD sensors are optically coupled to a single lens by a pyramidal mirror. Each CCD sensor reads a quarter of the image and the four quarter-images are combined into one HDTV picture. Discontinuities at the lines where the four images join can be eliminated by white- and dark-level correction and gamma correction. Moreover, smoothing processing using a weighted-mean method is performed to produce a seamless picture. With this processing the camera can consistently produce seamless pictures.

The barrier-layer was successfully fabricated for a preparation of tunneling junction using high Tc oxidesuperconductor such as Bi-Sr-Ca-Cu-O system. Bi2Sr2Ca2Cu3Ox films were used for both superconducting electrodes and the barrier was mainly Bi2Sr2CaCu2O and the rest that was formed by effects of de-calcium from the first sputtered (2223) film. The reaction of de-calcium occurred immersing it in carbonated water. The change of (2223) phase of BSCCO was confirmed with a comparison of the intensity of X-ray diffraction. The superconductive transition temperature of the junction is different from that of the single film (2223) which had no treatment with carbonated water. Zero-bias-currents through fabricated barrier are observed and the critical currents depend on temperature so far as measured temperature region of 79 K-72 K.

We have fabricated a thin head composed of a double layer magnetoresistive (MR) reproducing element and an inductive recording element for high density rigid disk drives. We have also developed a low noise reproducing amplifier IC whose input noise level is 0.3nV/Hz. Our experimental results indicate that equal electrical potential between the exposed area of the MR element and the medium's surface improves the durability of our MR head.

A superresolution technique is considered for use in antenna gain measurements. A modification of the MUSIC algorithm is employed to resolve incident signals separately in the time domain. The modification involves preprocessing the received data using a spatial scheme prior to applying the MUSIC algorithm. Interference rejection in the antenna measurements using the fast Fourier transform (FFT) based techniques have been realized by a recently developed vector network analyzer, and its availability has been reported in the literature. However, response resolution in the time domain of these conventional techniques is limited by the antenna bandwidth. The MUSIC algorithm has the advantage of being able to eliminate unwanted responses when performing antenna measurements in situations where the antenna band-width is too narrow to support FFT based techniques. In this paper, experimental results of antenna gain measurements in a multipath environment show the accuracy and resolving power of this technique.

Two kinds of nitrided ultrathin (510 nm) SiO2 films were formed on the silicon (100) face using rapid thermal NH3-nitridation (RTN) and rapid thermal N2O-oxynitridation (RTON) technologies. The MOS capacitors with RTN SiO2 film showed that by Fowler-Nordheim (F-N) electron injection, both electron trap density and low-field leakage increase by the NH3-nitridation. In addition, the charge-to-breakdown (QBD) value decreases owing to NH3-nitridation. By contrast, RTON SiO2 films exhibited extremely low electron trap density, almost no increase of the leakage current, and large QBD value above 200C/cm2. The oxide film composition was evaluated by secondary ion mass spectroscopy (SIMS). The chemical bonding states were also examined by Fourier transform-infrared reflection attenuated total reflectance (FT-IR ATR) and X-ray photoelectron spectroscopy (XPS) measurements. These results indicate that although a large number of nitrogen (N) atoms are incorporated by the RTN and RTON, only the RTN process generates the hydrogen-related species such as NH and SiH bounds in the film, whereas the RTON film indicates only SiN bonds in bulk SiO2. From the dielectric and physical properties of the oxide films, it is considered that the oxide wearout by high-field stress is the result of the electron trapping process, in which anomalous leakage due to trap-assisted tunneling near the injected interface rapidly increases, leading to irreversible oxide failure.

We propose a high-speed SOI bipolar transistor fabricated using bonding and thinning techniques. It is important to replace SOI area except for devices with thick SiO2 to reduce parasitic capacitance. A thin SOI film with a thin buried layer helps meet this requirement. We formed a 1-µm-thick SOI film with a 0.7-µm-thick buried layer by ion implantation before wafer bonding pulse-field-assisted bonding and selective polishing. Devices were completely isolated by thick SiO2 using a thin SOI film and the LOCOS process. We fabricated epitaxial base transistors (EBTs) on bonded SOI. Our transistors had a cutoff frequency of 32 GHz.

High Tc superconducting (SC) active antennas made from thin films were produced by the magnetron sputtering method. The SC active antennas are found to be good for detecting 50GHz electromagnetic waves. Furthermore, the improvement of the sensitivity of the SC active antennas is demonstrated with the use of a corner reflector.

A 0.1-µm-gate CMOS/SIMOX has been successfully fabricated using high quality SIMOX substrates. The propagation delay time for the 0.1-µm-gate CMOS/SIMOX is not so noticeable due to the parasitic resistance of the source and drain regions. We anticipate 0.1-µm-gate CMOS/SIMOX devices with a delay time of less than 20 ps at a supply voltage of 1.5 V by reducing the remaining parasitic resistance and capacitances.

Thin- and ultra-thin-film SOI MOSFET's are promising candidates to overcome the constraints for future miniaturized devices. This paper presents simulation results for a 0.1 µm gate length SOI MOSFET structure using a two-dimensional/two-carrier device simulator with a nonlocal model for the avalanche induced carrier generation. For the suppression of punchthrough effect in devices with a channel doping of 1 1016 cm-3 and 5 nm thick gate oxide it is found that the SOI layer thickness has to be reduced to at least 20 nm. The thickness of the buried oxide should not be smaller than 50 nm in order to avoid the degradation of thin SOI performance advantages. Investigating ways to suppress the degradation of the sub-threshold slope factor at these device dimensions it was found in contrast to the common expectation that the S-factor can be improved by increasing the body doping concentration. This phenomenon, which is a unique feature of thin-film depleted SOI MOSFET's, is explained by an analytical mode. At lower doping the area of the current flow is reduced by a decreasing effective channel thickness resulting in a slope factor degradation. Other approaches for S-factor improvement are the reduction of the channel edge capacitances by source/drain engineering or the decrease of SOI thickness or gate oxide thickness. For the latter approach a higher permittivity gate insulating material should be used in order to prevent tunnelling. The low breakdown voltage can be increased by utilizing an LDD structure to be suitable for a 1.5 V power supply. However, this is at the expense of reduced current drive. An alternative could be the supply voltage reduction to 1.0 V for single drain structure use. A dual-gated SOI MOSFET has an improved performance due to the parallel combination of two MOSFET's in this device. A slightly reduced breakdown voltage indicates a larger drain electric field present in this structure.