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We have successfully fabricated nickel silicide metal–oxide–semiconductor (MOS) capacitors at 280 °C by metal chloride reduction chemical vapor deposition (MCR-CVD). In this process, we first prepared polycrystalline silicon (poly-Si)/SiO2-overcoated Si wafers and exposed the wafers to Cl plasma containing NiCl for 40 min with a substrate temperature of 280 °C. During this process, the top layer of poly-Si is changed to a nickel silicide film with the Ni concentration at approximately 50%. Depth-resolved X-ray photoelectron spectroscopy (XPS) showed a uniform profile of the top film and a sharp interface on the SiO2 surface at such Ni concentration. We have also obtained capacitance–voltage (C–V) characteristics using a MOS capacitor from the processed wafer. We demonstrate the possibility and applicability of MCR-CVD in the near room temperature (RT) fabrication of metal gate MOS capacitors.

We have previously developed a method for measurement of a small change in thickness of the arterial wall during a single cardiac cycle [H. Kanai, M. Sato, Y. Koiwa and N. Chubachi: IEEE Trans. UFFC 43 (1996) 791]. The resultant change in thickness is shown to be useful for the in vivo assessment of the regional elasticity of the arterial wall. Although the accuracy of the measurement of the change in thickness is found to be within 1 µm, it is affected by the interference of ultrasonic pulses. In this study, we simulate the propagation of ultrasonic pulses transmitted and received by a linear probe. In the simulation experiments, the ultrasonic pulses generated by a computer are reflected by a tube, which has a small change in wall thickness of 10 µm. The optimum focal position of the ultrasonic beam is determined by evaluating the root-mean-square (rms) error in the measured change in thickness.

Ferroelectric SrBi2Ta2O9 thin films were synthesized on various substrates, such as MgO(100), glass, Pd/MgO(100) and Pd/glass by the rf magnetron sputtering method. Single-phase thin films were prepared on these substrates using a target with the starting chemical composition of SrCO3:Bi2O3:Ta2O5=0.7:1.2:1. At the higher substrate temperature of 1073 K, (h 0 l) orientation was found. The hysteresis loop of the thin film on Pd(100)/MgO(100) substrate did not change up to 109 switching cycles. These properties are very attractive for nonvolatile memory application.

A new high-T c superconductor Nd-Sr-Ce-Cu-O system has been found by the resistivity and magnetization measurements. The highest onset transition temperature is about 28 K. The superconducting phase may be described as (Nd1-x Sr x-y Ce y )2CuO4-δ.