Platinum chemical mechanical polishing (CMP) characteristics for high density ferroelectric memory applications

The key component of ferroelectric random access memory (FeRAM) is a capacitor including a ferroelectric thin film and electrode materials. Platinum is one of the suitable metals which meet requirements such as low resistivity, high thermal stability, and good oxygen resistance. Generally, the ferroelectric and the electrode materials were patterned by a plasma etching process. The application possibility of chemical mechanical polishing (CMP) processes to the patterning of ferroelectric thin film instead of plasma etching was investigated in our previous study for improvement of an angled sidewall which prevents the densification of FeRAM. In this study, the characteristics of platinum CMP for FeRAM applications were also investigated by an approach as bottom electrode materials of ferroelectric material in CMP patterning. The removal rate was increased from 24.81 nm/min by the only alumina slurry (0.0 wt% of H₂O₂ oxidizer) to 113.59 nm/min at 10.0 wt% of H₂O₂ oxidizer. Electrochemical study of platinum and alumina slurry with various concentrations of H₂O₂ was performed in order to investigate the change of the removal rate. The decreased particle size in the alumina slurry with an addition of 10.0 wt% H₂O₂ oxidizer made the improved surface roughness of the platinum thin films. Micro-scratches were observed in all polished samples.     

Integration of 5-V CMOS and High-Voltage Devices for Display Driver Applications

Reduced surface field lateral double-diffused MOS transistors for the driving circuits of plasma display panel and field emission display in the 120 V region have been integrated for the first time into a low-voltage 1.2 μm analog CMOS process using p-type bulk silicon. This method of integration provides an excellent way of achieving both high power and low voltage functions on the same chip; it reduces the number of mask layers and also the cost of fabrication. The lateral double-diffused MOS transistor with a drift length of 6.0 μm and a breakdown voltage greater than 150 V was self-isolated to the low voltage CMOS ICs. The measured specific onresistance of the lateral double-diffused MOS is 4.8 mΩ·cm² at a gate voltage of 5 V.     

Fiber grating sensors

We review the recent developments in the area of optical fiber grating sensors, including quasi-distributed strain sensing using Bragg gratings, systems based on chirped gratings, intragrating sensing concepts, long period-based grating sensors, fiber grating laser-based systems, and interferometric sensor systems based on grating reflectors     

Effect of simulated gastric fluid and bile on survival of Vibrio vulnificus and Vibrio vulnificus phage

Bacteria and phages may be exposed to acid conditions in the stomach and to bile in the intestine. Survival of three strains of Vibrio vulnificus and three strains of its phages was examined at 37 degrees C after exposure to simulated gastric fluid at pH 3 to 4 or to 0, 1, and 2% bile in broth or buffer. Mean D-values (decimal reduction times) at pH 4 and 3 were 3.3 and 1.3 min for V. vulnificus and 97.8 and 0.7 min for its phages. No V. vulnificus survivors were found at pH 2.0. There were few survival differences among strains of V. vulnificus or its phages. Numbers of V. vulnificus increased 1 log in tryptic soy broth containing 1 or 2% bile after 3 h. Numbers of V. vulnificus and its phages remained constant in phosphate-buffered saline regardless of bile concentrations up to 3 h. Those V. vulnificus bacteria and phages that survive stomach acidity may proliferate in the small intestine, since they are resistant to bile.     

降低视频子系统的工作和待机功耗

越来越多的便携式设备,例如数码相机、手机和便携式媒体播放器,都开始逐渐增加复合视频输出的连接功能。这类设备中,连接在视频DAC之后的视频滤波放大器产生视频信号。现有的3.3V视频滤波放大器处理视频信号时,功耗为45mW。电池使用时间是便携设备的关键,首先要考虑降低视频系统     

Tire Dynamic Deflection and Its Impact on Vehicle Longitudinal Dynamics and Control

Vehicle longitudinal dynamics are shaped by tire characteristics. A number of empirical tire models have been proposed to explain longitudinal tire behaviors. These models typically explain the static tire behaviors and overlook the behaviors during transients. As a result, they often do not reflect the dynamic interactions between the tire and the vehicle under operational environments, most noticeably, the longitudinal overshoots and oscillations that occur immediately after a vehicle is stopped with hard braking. This paper proposes a dynamic-deflection tire (DDT) model that not only specifies the known longitudinal tire characteristics but also captures the dominant tire transient properties. When incorporating this DDT model into a conventional vehicle longitudinal model, these often-ignored tire-vehicle structure modes can be predicted accurately. The resultant model shows that the tire transient characteristics do impact ride comfort and affect longitudinal control designs at low vehicle speeds. A passenger car was tested under both open-loop and closed-loop scenarios, and the experimental results verified the model predictions.     

A low-power highly linear cascoded multiple-gated transistor CMOS RF amplifier with 10 dB IP3 improvement

A low-power highly linear CMOS RF amplifier circuit composed of a Multiple-Gated common-source FET TRansistor (MGTR) in cascode configuration is reported. In a MGTR amplifier, linearity is improved by using transconductance linearization which can be achieved by canceling the negative peak value of g/sub m/" of the main transistor with the positive one in the auxiliary transistor having a different size and gate drive combined in parallel. This enhancement, however, is limited by the distortion originated from the combined influence of g/sub m/' and harmonic feedback, which can greatly be reduced by the cascoding MGTR output. IP3 improvement as large as 10 dB has been obtained from an experimental RF amplifier designed at 900 MHz and fabricated using 0.35 /spl mu/m BiCMOS technology using only CMOS at a similar power consumption and gain as those obtainable from conventional cascode single gate transistor amplifiers.     

A tree key graph design scheme for hierarchical multi-group access control

A tree key graph design scheme for hierarchical multi-group access control with low communication overhead is presented. A simulation result shows that the proposed scheme can reduce a communication overhead up to about 15.2% compared to the previously proposed scheme.     

Ballistic Spin Hall Transistor Using a Heterostructure Channel and Its Application to Logic Devices

In a ballistic spin transport channel, spin Hall and Rashba effects are utilized to provide a gate-controlled spin Hall transistor. A ferromagnetic electrode and a spin Hall probe are employed for spin injection and detection, respectively, in a two-dimensional Rashba system. We utilize the spin current of which polarization direction is controlled by the gate electric field which determines the strength of the Rashba effective field. By observing the spin Hall voltage, spin injection and coherent spin precession are electrically monitored. From the original Datta–Das technique, we measure the channel conductance oscillation as the gate voltage is varied. When the magnetization orientation of the injector is reversed by 180°, the phase of the Datta–Das oscillation shifts by 180° as expected. Depending on the magnetization direction, the spin Hall transistor behaves as an n- or p-type transistor. Thus, we can implement the complementary transistors which are analogous to the conventional complementary metal oxide semiconductor transistors. Using the experimental data extracted from the spin Hall transistor, the logic operation is also presented.     

Age-related leaf characteristics of surface features and ultrastructure of Dendropanax morbifera

Age-related morphological and anatomical changes were investigated by light and electron microscopy with juvenile and adult leaves of Dendropanax morbifera. Most juvenile leaves were glossy and palmate with five deep and narrow lobes divided nearly to two-thirds of the leaf base. Adult leaves were thick and possessed three lobes divided nearly to half of the leaf base. Stomata were ovoid and found on the abaxial surface. The epicuticular waxes of the plant included platelets, angular rodlets and threads. Platelets were attached to the surface at various angles. Distinct angular rodlets could be found on either the adaxial or the abaxial surface. Platelets on surface undulations occurred exclusively on the abaxial surface of adult leaves. Juvenile leaves were ca. 150?μm thick and had few intercellular spaces. Adult leaves were nearly two times thicker than juvenile leaves, and showed highly vacuolated cells and large intercellular spaces. The cuticle proper was apparent on the epidermis and showed distinctly alternating lamellate structures in juvenile leaves. The epidermal cell wall of adult leaves was covered with a cuticle layer for which a lamellate structure was not found. These results suggest that the species is heteroblastic in leaf characteristics with increasing leaf age.