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Broadband tunability is a central theme in contemporary nanophotonics and metamaterials research. Combining metamaterials with phase change media offers a promising approach to achieve such tunability, which requires a comprehensive investigation of the electromagnetic responses of novel materials at subwavelength scales. In this work, we demonstrate an innovative way to tailor band-selective electromagnetic responses at the surface of a heavy fermion compound, samarium sulfide (SmS). By utilizing the intrinsic, pressure sensitive, and multi-band electron responses of SmS, we create a proof-of-principle heavy fermion metamaterial, which is fabricated and characterized using scanning near-field microscopes with, Understanding the electromagnetic responses at subwavelength scales is important for achieving tunability. Using a combination of the near-field and far-field spectroscopy, the authors demonstrate a heavy fermion metamaterial with tunable dual-band optical responses by selectively and separately modifying the 4f and 5d band electrons.

金沢大学理工研究域機械工学系, A robot that simulates a number of human leg joint motions during carved turns has been developed. Each leg had six degrees of freedom like those of human athletes. An on-board computer controlled the sequence of joint angles in an open-loop mode during skiing on an artificial grass slope. The relations among joint motions, reacting forces and turn trajectory were investigated by programming various motions of the robot. At first, the effect of basic joint motions, such as abduction-adduction and flexion-extension of the hip, knee and ankle joints were investigated. Then the sequence of a top athlete's joint motions, measured in a separate study, was applied to investigate its effect on the ski turn. The human-inspired programme produced a more even force balance between the skis and also a higher-quality turn. The requirements for a successful physical model of a human skier are discussed. © 2009 International Sports Engineering Association.

A 29-year-old man presented with diplopia, dysarthria, anisocoria, oculomotor nerve paralysis, abducens nerve paralysis, right facial palsy, and spastic hemiparetic gait. Magnetic resonance imaging (MRI) showed a homogenously enhanced mass in the midbrain. MRI-guided stereotactic biopsy was performed, and the histologic diagnosis was pure germinoma. The tumor disappeared after chemotherapy and radiotherapy. Germinoma should be included in the differential diagnosis of midbrain lesions in young adults. MRI-guided stereotactic biopsy provided a helpful diagnostic clue in a patient with a midbrain lesion.

summary. Fibrin glue (FG) is frequently used to seal and cover the anastomoses in many operations such as cardiovascular surgery or orthopaedic surgery. However, in case of gastrointestinal surgery, anastomoses are potentially contaminated, and FG may promote bacterial growth, increasing the risk of leakage. The purpose of this study was to examine the effect of cryoprecipitate-derived FG (CryoFG) on bacterial growth. Bacterial growth on the CryoFG and on the commercial FG (Beriplast P®) was evaluated and compared with that on control medium. In addition, the complement activities were evaluated by heat inactivation or addition of guinea-pig complement to the experimental settings. The CryoFG inhibited the growth of Escherichia coli, whereas the commercial FG had no effect. Heat inactivation of the CryoFG inhibited the bactericidal effect of CryoFG. Addition of guinea-pig complement to the heat-inactivated CryoFG could almost restore the bactericidal activity, suggesting the important role of complement. This study showed that the CryoFG preserved the complement activity, which inhibited the in vitro growth of E. coli. Therefore, we concluded that the application of the CryoFG for gastrointestinal surgical anastomoses not only would be safe but also has the advantage of reducing bacterial infection.

Numerical simulation of the blanking process of sheet metals, i.e. the formation of rollover, burnish surface and burr, is done using a rigid–plastic finite element code developed by the authors. The Jeong expression is used as a ductile fracture criterion and is linked with the simulation. The rollover length increases as the clearance between the punch and die increases, and as the n -value of the material increases. On the other hand, the burnish length increases as the clearance decreases and the n -value decreases. The burr height increases linearly with respect to the radius of the tool edge. A conventional simulation method is proposed that predicts the formed burnish length from the clearance and n -value. To confirm the results of the finite element simulation, blanking experiments were also carried out using sheet metal of 3 mm thickness under various clearances and for different materials. The experimental results show good agreement with the finite element simulation results.

Photography is often used in geological survey, mining engineering or civil engineering to measure the length or width of an object by placing another object such as a scale, a hammer or a cigarette box next to the object. But, it is difficult to place a scale nearby the object when the object is too far and high or too dangerous to get to. In this study, practical applicability of the magnification equation of lens for indirect calculation of the length of a photographed object was examined. From this study, it was found that the applicable distance for the use of the magnification equation of lens was 84 m, even when the focal length was 36mm, and that the applicable distance was more than 300 m with the lens focal length being longer than 100 mm. Moreover, falling behavior, impact load and energy of a rock fall could be calculated readily using obtained information from a photograph.

Gutting characteristics of an aluminum sheet (Al 100P–O) on an anvil by the penetration of a wedge shape punch is investigated. Numerical simulations of the cutting process are conducted using a rigid plastic finite element code developed by the authors. Various expressions of fracture initiation are used as fracture criteria and linked with the simulation. The deformation characteristics of the sheet and the cutting force are calculated in terms of nose angle and radius of the wedge shape punch. The applicability of the fracture criteria and the effects of nose angle and radius on the fracture value distribution are discussed on the basis of the calculated results. The simulation results for the various fracture criteria were almost same, except for the Glift fracture criterion. The simulation results show that the fracture value increases with punch penetration depth and the highest value appears at the edge of the punch. It is also predicted that when the punch penetration depth reaches about 80% of the sheet thickness the crack initiates at the edge of the punch. To confirm the results of the simulations, cutting experiments are carried out and the cutting mechanism is observed. The experimental results are qualitatively in good agreement with the simulation results.

直腸カルチノイドは増加傾向にあり,好発部位が下部直腸という特殊性からその治療方針は慎重でなければならない.とくに腫瘍径20mm以下の病変の治療方針は各施設で模索中である.今回自験例49症例を対象に治療方針を検討した.腫瘍径5mm以下は24例,6～10mmは21例,11～20mmは3例,21mm以上が1例であった.内視鏡的切除を31例,うち外科的追加治療は11例,外科的切除は17例に施行した.内視鏡的切除は10mm以下の67%の腫瘍に行い,切除断端陽性でも摘出標本では全例腫瘍の残存を認めなかった.10mmでリンパ節転移例と16mmで肝転移例を1例認めた.治療方針としては腫瘍径10mm以下では基本的に内視鏡的切除をまず第1に考えるが,組織学的検討の結果により追加切除の必要性を考慮する.腫瘍径11mm以上では外科的切除を第1に考える.腫瘍径はひとつの目安であって,症例ごとに治療法の選択をする必要がある.

Human breast milk contains high concentrations of nitrate and nitrite in the early postpartum period. The acidification of nitrite leads to the generation of nitric oxide (NO) in the gastric lumen. NO reportedly plays an important role in adult stomachs. The objective of the present study was to determine whether NO is generated in the stomach of breastfed neonates. We examined (i) the concentrations of nitrite and nitrate in human breast milk and formula milk, according to the method based on the Griess reaction; (ii) the concentration of NO in gases collected from the lumen of the neonatal stomach; and (iii) NO generation in acidified milks in vitro, using a NO chemiluminescence analyser. We found that breast milk contained high levels of nitrite, the NO level in the stomach gas of neonates fed only breast milk peaked on days 2 to 5, and NO was present on the milk surface in vitro. These findings suggest that a high concentration of nitrite in the stomachs of breastfed neonates enables a high production of NO. We propose that breast milk is important in regulating the mucosal blood flow and gastric motility and in achieving bacteriostasis via induction of NO generation in the neonatal stomach.

In ITER, the vacuum vessel (VV) is designed to be a water cooled, double-walled toroidal structure made of 316LN stainless steel with a D-shaped cross section approximately 9 m wide and 15 m high. The design work which began at the beginning of the ITER-EDA is nearing completion by resolving the technical issues. In parallel with the design activities, the R&D program, Full-scale VV Sector Model Project, was initiated in 1995 to resolve the design and fabrication issues. The full-scale sector model corresponds to an 18° sector (9° sub-sector×2) and is being fabricated on schedule. To date, 60% of the fabrication had been completed. The fabrication of full-scale model including sector-to-sector connection will be completed by the end of 1997 and performance tests are scheduled until the end of ITER-EDA. This paper describes the latest status of the ITER VV design and the Full-scale Sector Model Project.

Enchondroma is a benign growth of cartilage arising in the bone metaphysis as a solitary or multiple primary lesions. The form of multiple enchondromatosis with unilateral predominance is termed Ollier's disease. We have recently treated a case of Ollier's disease with the chief complaint of deformity of the left hand. The patient was an 11-year-old boy. Radiographic examination showed honeycombed clear spaces in the metaphyses of the middle and proximal phalanges of the left ring and little fingers as well as of the fourth and fifth metacarpals, and thinning of the cortex of these bones, but with no evidence of pathological fracture. The tumors of the left fourth and fifth metacarpal bones and of the phalanges of the left ring and little fingers were removed, and the metacarpophalangeal joint of the little finger was capsulotomized. The patient was free from recurrence 19 months after surgery. With regard to the prognosis of Ollier's disease, malignant transformation into chondrosarcoma or osteosarcoma has been reported of the chondroma. Since Ollier's disease is self-limited in that it usually stops spontaneously as the patient grows, and since the cartilaginous lesions in occasional cases may regress or even disappear, any cartilaginous lesions that are still active or painful after termination of the growth period should be examined thoroughly under suspicion of undergoing malignant transformation.

To confirm the validity of self-awareness of daytime clenching, specific electromyogram (EMG) characteristics of clenching behaviour were determined using surface EMG recordings. Temporal muscle EMGs were recorded for 5 h in 13 subjects with self-reported clenching (clenching group: 27·5 ± 3·8 years old) and 12 subjects without self-reported clenching (control group: 28·6 ± 7·1 years old). All EMG data were recorded and stored on a portable EMG apparatus. The device was similar in size to a hearing aid, and suitable to record daytime EMG without restriction of daily activities. A clenching event was defined as muscle activity exceeding 10% of the maximum voluntary contraction. Furthermore, simultaneous voice recording was also performed to identify the corresponding EMG event as functional or parafunctional. The mean number of clenching events was 192·8 ± 228·8 and 24·8 ± 26·5 in the clenching and the control groups, respectively (P < 0·05, Mann-Whitney U-test); the number of functional events was not significantly different between the groups. Because there was a significant difference in the number of clenching events between the groups, self-reported daytime clenching is considered to be a reliable screening parameter for awake bruxism.

A monolithic wavelength converter of long-wavelength infrared radiation to short-wavelength infrared or visible radiation based on a quantum-well structure has been proposed and considered theoretically. The quantum-well converter utilizes intersubband electron transitions in the emitter quantum well. The threshold intensity of long-wavelength infrared radiation necessary for laser generation is evaluated as a function of the structural and physical parameters of the device.

Background. To the authors' knowledge, there have been no reports describing a case of malignant paraganglioma that produces both adrenocorticotropic hormone (ACTH) and interleukin-6 (IL-6). Methods. The clinical course and pathophysiology of a patient with Cushing's syndrome induced by ectopic ACTH syndrome caused by a cervical malignant paraganglioma with elevated plasma levels of IL-6 was investigated. Results. Ultrasonography, computed tomography, and magnetic resonance imaging of the neck revealed the presence of a tumor around the area from which the blood sample that showed the highest levels of ACTH and IL-6 was obtained by selective catheterization. Immunohistochemical staining of the removed tissue demonstrated the presence of ACTH and IL-6 proteins in the tumor cells. Reverse transcriptase-polymerase chain reaction also revealed the existence of IL-6 mRNA in those cells. Conclusion. The malignant paraganglioma of ectopic ACTH syndrome may produce IL-6. The present investigation provides new observations concerning ectopic ACTH syndrome.

Alveolar distraction osteogenesis (DO) is widely applied to correct alveolar ridge defects or atrophy. This chapter reports on the development of horizontal DO devices and investigates the utility of periosteal expansion osteogenesis.

The motion assist method is investigated in the case of daily action of elderly people whose muscle forces decline or nursing hard work. Full-body suit with the elastic elements along the muscle which acts motion assist function seems to assist the muscle load.

We investigated whether urinary neopterin concentrations respond to the pathological conditions (especially coronary artery dilatation) of Kawasaki syndrome. All of 29 children with Kawasaki syndrome had very high urinary neopterin concentrations. Increased urinary neopterin concentrations coincided with fever and with monocytosis in peripheral blood. The urinary neopterin excretion peaking within the first 8 days after onset correlated with the development of coronary artery dilatation. Increased urinary neopterin concentrations indicate that cell-mediated immunity is activated in patients with Kawasaki syndrome. Endogenous interferon-gamma and activation of monocytes/macrophages may play a role in the pathogenesis of Kawasaki syndrome. Not only do neopterin concentrations correlate with symptoms in the acute phase of Kawasaki syndrome, they also act as a predictive marker of coronary artery abnormalities in affected patients.

Iwano Y, Sugano N, Matsumoto K, Nishihara R, Iizuka T, Yoshinuma N, Ito K. Salivary microbial levels in relation to periodontal status and caries development. J Periodont Res 2010; 45: 165–169. © 2010 John Wiley & Sons A/S Background and Objective: Although an inverse relationship between caries and periodontal disease has been suggested, some studies have reported a positive correlation between periodontal disease and the decayed, missing and filled teeth (DMF) index. The aim of the present study was to examine the relationship between caries and periodontal disease. Material and Methods: We assessed the clinical parameters and salivary levels of Porphyromonas gingivalis and Streptococcus mutans using real-time polymerase chain reaction in 40 subjects with varying degrees of caries and periodontal disease. Results: The salivary levels of S. mutans were significantly higher in the periodontally healthy group than in the periodontitis group. The salivary levels of P. gingivalis were significantly higher in the caries-free group than in the periodontally healthy group with caries. The salivary levels of S. mutans were significantly increased after the initial periodontal treatment. Conclusions: This study showed that an inverse relationship exists between periodontitis and caries in terms of the clinical and bacteriological findings.

In a hard disk drive, the angular alignment of the read/write head relative to a data track varies with the radial position of the track, increasing a risk of data track misregistration. We present a frictionless rotary micromotor which can be used as a secondary stage actuator to maintain a constant angle between the head and the tracks during disk operation. The monolithic device is fabricated in single-crystal silicon using a single mask process based on standard Silicon-On-Insulator micromachining. The motor employs a flexural suspension of the rotor to avoid any mechanical contact during operation, enabling precise, repeatable and reliable stepping motion without feedback control. The preliminary experimental characterization of a prototype with a diameter of 1.15 mm has demonstrated a rotational range of 4.2o (+/−2.1o) at 45 V and a resolution of 0.14o in a coarse stepping mode.

A 1-in optical format frame-interline-transfer charge-coupled-device (FIT-CCD) image sensor with 2 million pixels and an aspect ratio of 16(H):9(V) has been developed for HDTV cameras. The effective number of pixels is 1920(H)*1036(V). In order to decrease the smear level, achieve uniform charge handling capability for the vertical CCD, and eliminate defects that appear as vertical stripes in the image of the device, aluminum wire was put onto the vertical transfer gate to decrease the resistance in the transfer gate and a dual-channel two-phase CCD was utilized for the horizontal shift register operated by a 37.125-MHz clock. As a result, this image sensor has a dynamic range of 72 dB and a sensitivity of 75 nA/lx for light with a color temperature of 2856 K. Smear is reduced to -100 dB by using the FIT-CCD image sensor structure. The horizontal limit is 1000 TV lines. In addition, image lag is negligibly small and below the sensitivity of the measurement instrument. >

This paper reports on low-power and high-speed resistive switching of a Ti-doped NiO memory, which is based on the switching mechanism of the redox reactions in a filamentary conductive path. A small reset current of less than 100 muA was achieved by controlling the gate voltage of a cell transistor, which acts as an excellent current limiter in the set operation. A fast reset time of less than 5 ns was achieved by doping the Ti into the NiO film. Ti is thought to be effective to not only stabilize the reset process by forming an oxygen reservoir, but also to suppress the abnormal set phenomenon during the reset operation due to the formation of strong Ti-O bonds. Moreover, stable pulse switching with a large resistance change ratio has been successfully demonstrated using a unipolar voltage source of less than 3 V.

X-ray dynamical diffraction phenomena at a Bragg angle near π/2 are studied. The X-ray transmissivity as well as the reflectivity from the (991) lattice plane of a silicon thin plate is observed. It agrees fairly well with the diffraction pattern calculated on the basis of the Darwin approach. The possibility is discussed whether a set of two crystal plates arranged face to face, in which the diffraction condition with a Bragg angle near π/2 is satisfied, may be used as a very high resolution monochromator.

SUMMARY This paper deals with the driving principle and the experimental demonstration of, a micro motor which can convert rotation into linear motion and generate large displacement. The motor is a wobble type one; its rotor and stators have screw threads. When the rotor turns, it moves linearly in the axial direction like a screw. The range of linear motion is limited only by the length of the rotor. The threaded wobble motor can be driven either magnetically or electrostatically. We have fabricated a magnetic version having a rotor of lmm in diameter and operated it successfully.

Deregulation of electric power market is now in progress in Japan, and various kinds of power sources are emerging. Then, economical and efficient coordinating operation of existing and new facilities is needed. In this study, two types of new control software have been developed to meet variety of customers' needs. One is called "optimum economical dispatching program", which realizes optimum operation among various power sources, such as gas turbines, fuel cells, energy storage system and utility supply menu. The other is called "load following program", which controls generators to follow the varying loads. Also, the "control and interface unit", which sends and receives control and supervisory data of generators and loads, had been developed as a SCADA system. In this paper, newly developed controlling programs and control and interface unit will be introduced with the test results using the analogue power system simulator.

We present an ultra-high-performance 0.13-/spl mu/m embedded DRAM technology, which improves transistor performance in both logic devices and DRAM cells. Simulation results indicate that the typical random access cycle of a 16-Mbit DRAM core exceeds 570 MHz. The full-metal DRAM structure having a newly developed TiN/HfO/sub 2//TiN/W capacitor minimizes the aspect ratio of the cylindrical capacitor electrode to reduce contact resistance in the logic area. Integration of the embedded DRAM with BSTSOI (Body-Slightly-Tied SOI) is also demonstrated, with which the logic performance can be further improved and the DRAM cell area is free from floating-body effects.

We have directly observed the energy distributions of hot electrons in Si-MOSFETs for the first time. This was accomplished by using a lateral hot-electron transistor (LHET) with two potential barriers: an emitter barrier and a collector barrier. Since the gate length of MOSFETs continues to be scaled down and the electrical fields in the channel tends to increase, hot-carrier injection increasingly occurs. The hot carriers cause the device degradation, also give rise to the advantage of velocity overshoot which leads to higher transconductance. To forecast future MOSFETs, it is thus important to estimate the energy distribution of hot carriers in a decanometer-gate-length regimes.

This paper deals with the driving principle and the experimental demonstration of a micro motor which can convert rotation into linear motion and generate large displacement. The motor is a wobble type one; its rotor and stators have screw threads. When the rotor turns, it moves linearly in the axial direction like a screw. The range of linear motion is limited only by the length of the rotor. We have fabricated a threaded wobble motor by the electromagnetic actuation and operated it successfully.

The design and characteristics of a micro X-Y-/spl theta/ conveyor by superconducting magnetic levitation are reported. This actuator consists of three parts: a high temperature superconductor (HTSC) of 25 mm in diameter and 2 mm thick; a stator layer made by patterned electrodes; and a slider (3/spl times/3/spl times/1.1 mm/sup 3/) with four permanent magnets of 1/spl times/1/spl times/1 mm/sup 3/ each. We can control the position of the slider by operating the current of patterned electrodes. The linear stepping actuation has been previously achieved. In this study, the linear and rotating motion of the slider is reported. The continuous linear actuation and rotation are also achieved by controlling the duty ratio of 1 kHz square pulse current between the two adjacent electrodes. >

A tea serving robot for bedridden people is proposed in this paper. The tea serving robot is a standing-on-the-floor type with light weight, requiring a small installation area, and can be easily moved. A robot arm and hand can grasp a tea cup and carry it three dimensionally. A weak stiffness cantilever arm is used as the robot arm in order to ease bedridden people's tension. The bedridden person can easily catch and stop the robot arm and hand. The vibration reducing control of the robot arm is considered. The tea serving robot is actuated following the voice instruction. Therefore, the bedridden person can easily order the robot to carry a cup of tea.

Welfare robot technology to assist aged persons is presented. The tea serving robot can carry a cup of tea according to human instructions. The suspended-from-ceiling type tea serving robot requires no installation area since the robot hand is suspended from the ceiling of a house. The standing-on-floor type tea serving robot can be easily moved due to its rod structure which is equipped with a three directional drive mechanism and a robot hand. The idea for the standing-on-floor type robot came from a drip transfusion stand in hospitals. Two types of robots which assist in walking and moving up-and-down stairs were also developed. Both types use a handrail of a house to assist aged persons. The stick type robot can assist in walking and moving up-and-down stairs using tires and rubber belts. The biped type robot can assist using a structure with two legs.

Recent design progress of the vacuum vessel for the International Thermonuclear Experimental Reactor is presented. A structural design strategy has been developed for the VV in which the VV will be designed, fabricated, and tested per the requirements of the ASME Code Section VIII, Div. 2. The inboard structure that was originally designed polygonal cylinder has been modified to a cylindrical shape in order to resist the induced forces due to the fast current discharge of the TF coil. The shielding material under the TF coils in the upper outboard region has been changed to a ferromagnetic material (SS 430) instead of SS 30467 to reduce toroidal field ripple. The thermal and hydraulic analyses indicate sufficient heat removal capability from the VV. Although detailed design modifications continue to be made to reinforce areas of high stress and to accommodate interfaces with other systems, problems completing the design from a structural standpoint are not anticipated.

The design and the driving characteristics of a micro conveyor based on superconducting magnetic levitation are reported. This actuator consists of three parts; a superconductor (Y-Ba-Cu-O), a stator layer made by patterned copper electrodes (line pitch: 180 /spl mu/m, width: 70 /spl mu/m) on the polyimide film and a slider with four permanent magnets (the size of one magnet is 1 mm cube). This conveyance actuator is free from particle generation, because there is no friction by the magnetic levitation. The position of the slider is controlled by the current in the patterned electrodes. We have obtained quick conveyance (280 /spl mu/m/s over 2.8 mm) and precise positioning with an accuracy of 40 /spl mu/m by combining the step actuation in the entire area and the micro-step actuation in the local area near the target position.

A novel device-the quantum-wire infrared phototransistor-is proposed and evaluated. It is shown that this device can surpass in performance the quantum-well phototransistor.

Two types of circularly polarized linear antenna having a rhombic loop configuration are investigated. One type of circularly polarized antenna is a single feed dual rhombic loop antenna (DRLA). The DRLA consists of two rhombic loops of the same size and is located above an infinite ground plane. The other is a hula hoop antenna (HHA). The HHA is fed from a coaxial cable, of which the inner conductor is connected to the antenna itself and the outer conductor is connected to the ground plane. Two types of feed are introduced for each of the DRLA and the HHA. The antenna characteristics for each feed model are calculated by the method of moments. The results are in good agreement with the measured data.

We have developed a 0.13 /spl mu/m embedded DRAM technology, which targets high-speed and low-voltage operation, with logic performance fully compatible with 0.13 /spl mu/m pure logic. Parasitics (resistance, capacitance) of the DRAM macro limit its performances due to RC delay and IR drop. The parasitics of the new DRAM have been successfully minimized by employing the Full Metal embedded DRAM (FMD) technology which consists of a Metal-Insulator-Metal (MIM) capacitor with metal contact, and a newly developed low resistivity bitline. The results of performance simulation using a 16 Mbit DRAM macro show 1.2 V, 450 MHz of high-performance random access operation.

We have developed embedded DRAM technology, in which 0.15 /spl mu/m logic transistor performance is fully compatible with that of pure logic processes. The key technology is the newly developed MIM capacitor element with W-TiN-Ta/sub 2/O/sub 5/-TiN structure. Temperatures as low as 500/spl deg/C are sufficient for the formation process for this MIM capacitor element. Excellent leakage current characteristics of 8/spl times/10/sup -15/ A//spl mu/m/sup 2/ at 125/spl deg/C with T/sub eq/ (equivalent oxide thickness) of 17 /spl Aring/ have been obtained. This technology has been actually implemented into a 4 Mbit test chip with cell size of 0.425 /spl mu/m/sup 2/. Over 50% yield without redundancy was obtained, confirming that there are no basic issues in process integration.

This paper deals with microactuators for the precise positioning of read/write heads in very-high-density magnetic hard disk drives. In order to satisfy required specifications, namely the displacement of /spl plusmn/0.5/spl mu/m at or below 20V and the structural resonance frequency of 15kHz the electrostatic gap, the mover and the stator must be very small (/spl sim/2/spl mu/m) and its aspect ratio must be high (/spl sim/50). We developed the vertical sacrificial layer process to realize such high-aspect-ratio gaps.

Micro actuators are developed for hard disk drive application. The aim is high density data storage by positioning the read and write head element precisely. The desired specifications are displacement of /spl plusmn/1 /spl mu/m, operating voltage of 20 V and structural resonance frequency of 151 Hz. We fabricated a metallic actuator by using thick photoresist lithography and nickel electroplating. The electrostatic gap between the mover and the stator has high aspect ratio to achieve low voltage operation. We introduce a vertical sacrificial layer of copper to make the electrostatic gap. We utilize photoresist with thickness of 10 /spl mu/m. We completed the process and operated the actuator successfully. We also developed a silicon actuator using silicon deep etching and deposition technology. We use ICP-RIE for silicon etching and LPCVD for deposition of the vertical sacrificial layer of SiO/sub 2/ and the mover structure of polysilicon. We obtained an actuator which had thickness of 100 /spl mu/m with electrode gap of aspect ratio of 50.

We investigated the degradation of device reliability due to Negative Bias Temperature Instability (NBTI) of PMOSFET with ultrathin gate oxide. It was experimentally demonstrated that the chemical reactions at the gate oxide/substrate interface and/or diffusion of hydrogen related species are the major cause of the NBTI. We also found that nitridation of gate oxide enhances NBTI. In order to suppress the NBTI, the density of hydrogen terminated silicon bond at the interface needs to be minimized. Thus, the concentration of nitrogen in thin gate oxide has to be optimized in terms of the reliability reduction due to NBTI.