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We have discovered new transparent conducting oxides (TCOs), anatase Ti1-xMxO2 (M=Nb,Ta), in thin film form. Both films with 0.03 ≤ × ≤ 0.06 showed resistivity of 2−3 × 10−4 Ωcm and internal transmittance of ∼95% in the visible light region (40 nm in thickness), at room temperature. These values are comparable to those of typical TCOs, such as In2−xSnxO3 (ITO).

We developed a scanning microwave microscope (SμM) designed for characterizing local electric properties at low temperatures. A high-Q λ/4coaxial cavity was used as a sensor probe, which can detect the change of quality factor due to the tip-sample interaction with enough accuracy. From the measurements of combinatorial samples, it was demonstrated that this SμM system has enough performance for high-throughput characterization of sample conductance under variable temperature conditions.

In this paper, we demonstrate the use of thermal probe method that is capable of mapping Seebeck coefficient, thermal conductivity and contact resistance on a micrometer scale. We show the successful screening example on pseudo binary (Bi1−xSbx)2Te3 (0.5

This paper demonstrates a new technique to form a patterned metal-oxide film on a silicon wafer using a local electric field. The idea of the technique involves using an interaction between metal-organic molecules dissolved in a non-polar solvent and a local electric potential field on a substrate. In this paper, an alkoxide and a metal-organic complex were used as metalorganic precursors. The precursor molecules were selectively deposited at the electrified region of the substrate. The deposited precursor films were heated with an electric furnace to form oxide films. Patterned TiOx and Sr-Ti oxide films were formed on a SiOx/Si substrate. These patterned thin films are potentially applicable to electric and optical devices. We believe that this new technique provides a new bottom-up process of molecular assembly for nanofabrication.

The prospect of lattice structure and ferroelectricity of SnTiO3 have been studied by first-principles calculations within local density approximation. The results showed that the SnTiO3 has the minimum total energy within almost tetragonal perovskite structure of a=b=3.80 Å, c=4.09 Å. The calculated electronic structure of SnTiO3 resembles that of PbTiO3 because the Ti 3d states, Sn 5s and 5p states hybridize with the O 2p orbitals. The moment of spontaneous polarization of SnTiO3 was estimated as 73 μ C/cm2, which is as large as that of PbTiO3.

Magnetic properties of Co-doped rutile (Ti1-xCoxO2) film in combinatorial composition-spread form have been surveyed by means of a Scanning Superconducting-quantum-interference-device Microscope (SSM). As a consequence, we found magnetic domains in the spatial regions with x>0.05 without external field, giving strong evidence for ferromagnetism with finite spontaneous magnetization. The magnetic moment was monotonously increased with increasing doping level x from 0.05 to ∼ 0.13. On the other hand, it was almost unchanged for x > ∼ 0.13, suggesting that Co does not dissolve into rutile film beyond x ∼ 0.13. The SSM results on the rutile Ti0.95Co0.05O2 thin films with different thickness showed that the magnetic moment is proportional to film thickness, leading to a conclusion that the presently observed ferromagnetism does not result from Co or Co-based oxide particles on the film surface.

We have investigated a resist-trimming process for SAL601 chemically amplified negative electron beam resist. Ultra-fine SAL601 resist patterns with a width of 16nm were obtained by an isotropic trimming process in oxygen plasma. This pattern resolution in SAL601 could not be obtained through direct electron beam lithography alone. Using the trimmed electron beam resists, we have successfully fabricated ultra-fine poly-silicon patterns of less than 20nm width. We applied this nanolithography technique to fabricating an ultra-small metal-oxide-semiconductor field-effect-transistor (MOSFET) and revealed that this trimming process is a useful method for nanometer-scale silicon device fabrication.

Ordered GaAs micro crystal growth on a As-terminated Si (001) surface was demonstrated using a low energy focused ion beam. Si (001) surface was terminated by Arsenic. The surface showed a (2×1) structure with As dimers. The As layer was sputtered periodically with low energy focused Ga ion beam. Supplied Ga atoms migrated on the surface and trapped at the As removed region, forming Ga droplets. GaAs micro crystals were grown from Ga droplets by As molecule supply. The proposed method was shown to be effective as a fabrication method.

A selective growth of GaAs micro crystals was demonstrated on a Se-terminated GaAIAs surface by sequential supplies of Ga and As molecules for the quantum well box structure. After the growth, the surface consisted GaAs micro crystals with (111) facets and some Se clusters. The cross sectional investigations by the high resolution electron microscope revealed an epitaxial growth of GaAs micro crystals on the surface and a mixture of Ga2Se3 and A12Se3 layer formation at the interface of GaAs/Se-terminated GaAIAs. The selenidation process seems to be a reaction limited one. The Se cluster segregation could be avoided by selenidation in As molecule atmosphere.

A selective growth of GaAs microcrystals was demonstrated on a Se-terminated GaAlAs surface. Ga molecules were supplied to the Se-terminated GaAlAs surface at first. The surface consisted of Ga droplets and bared Se-terminated GaAlAs surface. After the following As molecule supply to the surface, a selective GaAs microcrystal growth from Ga droplets was observed. The cross sectional investigations by the high resolution electron microscope revealed epitaxial growth of GaAs microcrystals with (111) facets and a possibility of (GaAl)2Se3, layer formation at the GaAs/Se-terminated GaAlAs interface.