Kazuhiro Kanda

Three-dimensional nanostructure fabrication by focused-ion-beam chemical vapor deposition

Three-dimensional nanostructure fabrication has been demonstrated by 30 keV Ga+ focused ion beam assisted deposition using a aromatic hydrocarbon precursor. The characterization of deposited film on a silicon substrate was performed by a transmission microscope and Raman spectra. This result indicates that the deposition film is a diamondlike amorphous carbon. Production of three-dimensional nanostructure is discussed. Microcoil, drill, and bellows with 0.1 μm dimension were fabricated as parts of the microsystem. Furthermore, microstructure plastic arts is advocated as a new field using microbeam technology, presenting one example of a microwine glass with 2.75 μm external diameter and 12 μm height.

Brilliant Blue Observation from a Morpho-Butterfly-Scale Quasi-Structure

The Morpho-butterfly wing reflects interfered brilliant blue, which originates from nanostructures on its scales, for any incidence angle of white light. We have, for the first time, fabricated a Morpho-butterfly-scale quasi-structure using focused-ion-beam chemical-vapor-deposition (FIB-CVD) and observed brilliant blue reflection from this quasi-structure with an optical microscope. We measured the reflection from real Morpho-butterfly scales and from the quasi-structure with a photonic multi-channel spectral analyzer system. The reflection spectra of the quasi-structure were very similar to those of Morpho-butterfly scales.

Free-space-wiring fabrication in nano-space by focused-ion-beam chemical vapor deposition

Focused-ion-beam chemical vapor deposition (FIB-CVD) is an excellent technology for forming three-dimensional nanostructures. Various diamond-like-carbon (DLC) free-space-wirings have been demonstrated by FIB-CVD using a computer-controlled pattern generator, which is a commercially available pattern generator for electron-beam (EB) lithography. The material composition and crystal structure of DLC free-space-wiring were studied by transmission-electron microscopy and energy-dispersive x-ray spectroscopy. As a result, it became clear that DLC free-space-wiring is amorphous carbon containing a Ga core in the wire. Furthermore, the electrical resistivity measurement of DLC free-space-wiring was carried out by two terminal electrodes. Au electrodes were fabricated by EB lithography and a lift-off process. The electrical resistivity was about 100 Ω cm at room temperature.

Characterization of Hard Diamond-Like Carbon Films Formed by Ar Gas Cluster Ion Beam-Assisted Fullerene Deposition

The coordination of carbon atoms in diamond-like carbon (DLC) thin films formed by Ar gas cluster ion beam (GCIB) assisted deposition using fullerene as the carbon source was investigated by measuring near-edge X-ray absorption fine structure (NEXAFS) spectra of the carbon K-edge over the excitation energy range 275–320 eV, using synchrotron radiation. With attention to the peak corresponding to the transition of the excitation electron from a carbon 1s orbital to a π* orbital, relative sp2 contents of various DLC films were estimated. The sp2 contents of the DLC films formed by the GCIB-assisted deposition were observed to be lower than those of the DLC films formed by other methods. The hardness value measured with a nano-indentation technique was found to be strongly related to the sp2 content of the DLC film.

Nanomanipulator and actuator fabrication on glass capillary by focused-ion-beam-chemical vapor deposition

Three-dimensional (3D) nanostructures on a glass capillary have a number of useful applications such as manipulators, actuators, and sensors in the various microstructures. We observed a phenomenon that two diamondlike-carbon pillars on a tip of glass capillary fabricated by 30 keV Ga+ focused-ion-beam-chemical vapor deposition (FIB-CVD) with a precursor of phenanthrene vapor was able to work as a manipulator during FIB irradiation. It became clear that it was caused by electronic charge repulsion between two pillars, which accumulated electric charge by FIB irradiation. By applying this moving mechanism, we have developed a 3D nanomanipulator and actuator on a tip of glass capillary by FIB-CVD. Furthermore, in situ observations of movement for a 3D nanomanipulator and actuator have been demonstrated by applying voltage onto a Au-coated glass capillary.

Development of three-dimensional pattern-generating system for focused-ion-beam chemical-vapor deposition

We studied the fabrication of free-designed three-dimensional (3D) structures by using focused-ion-beam chemical-vapor deposition. The 3D structures are fabricated by scanning 30 keV Ga+ ion-beam-assisted deposition in a 1×10−4 Pa phenanthrene atmosphere. The scanning pattern and blanking signal of the ion beam are generated by a 3D computer-aided-designed model using a computer pattern-generating system. This 3D pattern-generating system is able to fabricate overhang and hollow structures by setting suitable parameters (for example, plot pitch, dwell time, time interval of irradiations, and priorities of scanning). In this article, we demonstrate the performance of a 3D pattern-generating system by fabricating a 1:100 000 000 scale model of the Enterprise spaceship, a microring, a moth’s eyelike structure, and a morpho butterflylike structure with 200 nm spacing.

Fluorinated diamond-like carbon coating as antisticking layer on nanoimprint mold

Fluorinated diamond-like carbon (F-DLC) has recently been applied as an antisticking layer on nanoimprint molds for semipermanent use, replacing the self-assembled monolayer currently used. An SiO2/Si mold was successfully coated with an F-DLC thin layer by chemical vapor deposition (CVD). The measured water contact angle of the F-DLC surface was 103°, which is 30° higher than that of the DLC surface. This value indicates the adequacy of F-DLC as an antisticking layer. Moreover, an F-DLC film had a high hardness of 24 GPa, similar to that of a DLC film (26 GPa). AZ resist patterns of 150 nm linewidth and 350 nm pitch were successfully obtained by thermal nanoimprinting using an F-DLC-coated mold. Finally, after repeating the imprinting for more than 100 times, the initial water contact angle of 103° for the surface of the F-DLC-coated mold was maintained.

Nozzle-nanostructure fabrication on glass capillary by focused-ion-beam chemical vapor deposition and etching

Three-dimensional nanostructures on a glass capillary have a number of useful applications such as manipulators and sensors in the various microstructures. This time, we have demonstrated the fabrication of a nozzle nanostructure on a glass capillary for a bio injector by 30 keV Ga+ focused-ion-beam assisted deposition with a precursor of phenanthrene vapor and etching. It has been demonstrated that nozzle nanostructures with various shapes and sizes have been successfully fabricated. An inner tip diameter of 30 nm on a glass capillary and a tip shape with an inclined angle have been realized.

Optical measurement and fabrication from a Morpho-butterfly-scale quasistructure by focused ion beam chemical vapor deposition

The Morpho-butterfly wing reflects interfered brilliant blue, which originates from nanostructures on its scales, for any incidence angle of white light. We have fabricated a Morpho-butterfly-scale quasistructure using focused ion beam chemical vapor deposition and observed brilliant blue reflection from this quasistructure with an optical microscope. We measured the reflection from real Morpho-butterfly scales and from the quasistructure with a photonic multichannel spectral analyzer system. The reflection spectra of the quasistructure were very similar to those of Morpho-butterfly scales.

Three-Dimensional Nanoimprint Mold Fabrication by Focused-Ion-Beam Chemical Vapor Deposition

Three-dimensional diamond-like carbon (DLC) mold fabricated by focused-ion-beam chemical vapor deposition (FIB-CVD) using a precursor of phenanthrene has been applied to a nanoimprint process. Various 3D nanostructure DLC molds have been delineated by FIB-CVD using a computer-controlled pattern generator which is a commercially available pattern generator for electron beam lithography. Then, the molds were imprinted into hydrogen silsequioxane (HSQ) as a material replicated at room temperature. It was confirmed that the 3D mold, after nanoimprint lithography (NIL), kept its original shape, and 3D mold structures were successfully imprinted into HSQ. These results reveal that the 3D mold fabricated by FIB-CVD can be applied to NIL.