Three dimensional microfabrication of polytetrafluoroethylene was carried out by applying moving mask technique to synchrotron radiation direct photo-etching. Firstly, basic experiments to determine the dependence of processed depth and surface roughness on several parameters such as beam current, exposure time and substrate temperature were carried out. Increase in beam current, exposure time and substrate temperature realized improvement of surface roughness as well as processed depth. Because of strong dependence of processed depth on the several parameters, the dose defined by product of beam current and exposure time was hardly applied for the control of processed depth. As test structures of 3D microfabrication by moving-mask, conical microstructures were successfully fabricated and the possibility of flexible 3-D micromachining of polytetrafluoroethylene was demonstrated.

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The approach-contact-deformation-fracture process at a gold nano contact using a micromachined device was successfully observed in a high resolution transmission electron microscope (HRTEM). MEMS opposing tips (a movable tip with a pair of electrostatic actuators and a fixed tip) was inserted into a HRTEM chamber. When the movable tip was approached to the fixed tip within 1 nm, gold nano contact was formed with 1 V bias voltage. The gold nano contact was thinned by retraction and finally fractured. The series of the formation, retraction and fracture were observed in an atomic scale.

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In order to obtain the physical property of polypropylene and vapor growth carbon fiber (VGCF) composite material, a novel contact probe structure, C-probe, for the measurement of static capacitor is proposed. The present method utilizes the difference in dielectric constant of composite depending on the VGCF concentration. The C-probe contacted to the surface of the measuring object measures the resonance frequency between the electrodes arranged in plane (horizontal structure). In comparison with the conventional capacitor method, in which the specimen is clamped between the electrodes (vertical structure), the C-probe is advantageous because it realizes quick and non-destructive measurement. The experimental result shows good relationship between the compound ratio and the resonance frequency. By decreasing the dimension of the C-probe to be less than the composite specimen, the dispersion of mixture of the composite material has been also identified successfully.

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Evidence has been presented that the mixed anhydrous hydrogen fluoride (HF) and methanol (CH₃OH) gas, which is used for dry etching the sacrificial layer of silicon dioxide film, deteriorates silicon nitride film (SiN). From the results of chemical composition analyses, the alteration product was identified to be ammonium hexafluorosilicate ((NH₄)₂SiF₆). We found that the alteration product can be decomposed and removed by heat-treatment in atmosphere. The deterioration of the SiN by the HF/CH₃OH gas treatment is approximately 3 nm/min, and the growth rate of the SiN alteration product is approximately 30 nm/min.

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This paper describes a built-in capacitive displacement sensor for microactuators. The sensor with long full-scale range is developed for electrostatic microactuators that have a large out-of-plane motion range. A carrier wave with a frequency of 24 MHz is utilized to measure the capacitance between the moving electrode and the sensing electrode of the actuator. The zero method, wherein an additional feedback signal cancels the received signal at the sensing electrode, is applied. The method prevents the fluctuation of the displacement signal caused by the high driving voltage for the electrostatic actuator. The validity of the sensor is demonstrated by using a large-size actuator prior to applying the sensor to an actual microactuator. The acquired full-scale range, sensing band, resolution and linearity were respectively 4.5 mm, from DC to 30 kHz, 60 μm on average, and ±2.5%FS.

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