We collected diarrhoea specimens in two hospitals in southern Thailand in 1999 to examine whether infection by the Vibrio parahaemolyticus pandemic clone is prevalent. V. parahaemolyticus was isolated from 317 specimens. Seventy-six per cent of the isolated strains had the pandemic clone-specific characteristics (tdh+, trh−, and an unique toxRS sequence detectable by GS-PCR) and an associated characteristic (the ORF8 sequence of f237 phage). These strains belonged to the three pandemic servovars with the O3[ratio ]K6 strains being dominant and three other serovars (O1[ratio ]K25, O1[ratio ]K41 and O4[ratio ]K12). We also found O1[ratio ]K25 and O1[ratio ]K41 strains with the pandemic clone-specific characteristics among the strains isolated from the international travellers who left Thailand and three other Asian countries between 1998 and 1999, verifying pandemic potential of these strains. The results demonstrate prevalence of infection by the pandemic clone in southern Thailand and suggest emergence of various serovariants in this area and their implication in international spread.

We review our capacitor technology using (Ba,Sr)TiO3 (BST) as a capacitor dielectric for dynamic random access memory (DRAM) application. Among a number of issues for BST capacitor process integration in DRAM cells, two important technologies are discussed. As an electrode technology, we propose All PErovskite Capacitor (APEC) technology, in which conducting perovskite oxide of SrRuO3 (SRO) is used as capacitor electrodes. For chemical vapor deposition (CVD) of BST, we propose In-situ Multi-Step (IMS) process, which is a sequential repetition of low temperature deposition of ultra thin BST film and crystallization in the same chamber. By using APEC technology and IMS CVD process of BST, we can simultaneously achieve good electrical characteristics (low leakage current and high permittivity) and good step coverage. The combination of APEC technology and IMS CVD process of BST is a promising BST capacitor process technology for future DRAMs.

We have confirmed that grain boundaries are related to leakage problems in Ta2O5/SiON capacitors for high dielectric DRAMs. XRD studies using an intensity ratio of (200) to (001) showed that the crystallographic structure of Ta2O5 film was strongly dependent on preparation conditions. As the (200) oriented grains grew faster than the other grains, it became important to control its grain growth in forming uniform grain boundaries. TEM observation has shown that Ta2O5 film with a high intensity ratio of (200) to (001) was made up of large size grains and had SION interface intruding into grain boundaries. By using the current-mode AFM, we could monitor leakage current directly through grain boundaries on Ta2O5 film.

Medium-energy ion spectroscopy using a conventional ion implanter has been developed to study the properties of semiconductor subsurface regions. The system is equipped with solid state detector and operaties with He+ ion energy up to 200 keV. We have tested the system performance for various applications, such as, silicon diffusion through a thin Au layer, a low dose, low energy As implantion and damage of silicon surface caused by plasma treatment.

A microbeam line with precisely designed quadrupole magnets has been developed and installed at the Research Center for Extreme Materials, Osaka University. For the purpose of applying the beam line to microbeam RBS/channeling, the damage in <100>Si due to the irradiation of probe beams was studied as a function of incident ion dose from 1015 to 1018 /cm2 with a flux of 8 × 104 nA/cm2. It was found that the dose for channeling measurements should be less than several 1017 /cm2.

A nuclear microprobe-forming system for the microscopic RBS/PIXE measurement of micro devices has been developed and installed at the Research Center for Extreme Materials, Osaka University. The use of precision quadrupole magnets and an objective collimator ensures a final spot size of less than 1μm.