Three-dimensional Nanostructure Fabrication Research Articles

Systematic features of the formation of semiconductor nanostructures using a focused ion beam

The systematic features of three-dimensional nanostructure fabrication using a focused ion beam are studied. The dependence of the depth of ion-beam-modified structures on the number of etching passes for the same ion dose is revealed with the aim of achieving accurate and predictable nanostructure formation. At the qualitative level, the effect of the thermodynamic parameters of Si, GaAs, and GaN semiconductors on the results of etching is analyzed.

Three-Dimensional Nanostructure Fabrication by Controlling Downward Growth on Focused-Ion-Beam Chemical Vapor Deposition

Focused-ion-beam chemical vapor deposition (FIB-CVD) is a key technology to achieve the arbitrary three-dimensional (3D) nano- and microstructure fabrication. However, most of 3D nanostructure fabrications have focused on upward or lateral growth whereas few of them focused on downward growth. The downward growth characteristics of air nanowires were investigated in order to achieve the fabrication of more arbitrary 3D nanostructures. As a result, it was not able to fabricate a 1 µm long downward growth nanowire with an angle lower than -10°. Also, we found that a nanowire with an angle lower than -18° cannot be fabricated. Furthermore, we demonstrated the fabrication of 3D nanostructure including downward growth by changing the scan speeds of Ga+ FIB during fabrication. With controlling the downward growth, the fabrication of more various 3D nanostructures can be achieved.

Three-Dimensional Nanostructure Fabrication by Controlling Downward Growth on Focused-Ion-Beam Chemical Vapor Deposition

Focused-ion-beam chemical vapor deposition (FIB-CVD) is a key technology to achieve the arbitrary three-dimensional (3D) nano- and microstructure fabrication. However, most of 3D nanostructure fabrications have focused on upward or lateral growth whereas few of them focused on downward growth. The downward growth characteristics of air nanowires were investigated in order to achieve the fabrication of more arbitrary 3D nanostructures. As a result, it was not able to fabricate a 1 µm long downward growth nanowire with an angle lower than -10°. Also, we found that a nanowire with an angle lower than -18° cannot be fabricated. Furthermore, we demonstrated the fabrication of 3D nanostructure including downward growth by changing the scan speeds of Ga+ FIB during fabrication. With controlling the downward growth, the fabrication of more various 3D nanostructures can be achieved.

Realization of Three-Dimensional Nanostructure Fabrication by Nanoimprint on Silicon Substrate

Traditional optical lithography techniques to fabricate three-dimensional (3D) nanostructures are complicated and time consuming. Due to the capability to replicate nanostructures repeatedly in a large area with high resolution and uniformity, nanoimprint (NI) has been recognized as one of the promising approaches to fabricate 3-D nanostructures with high throughput and low cost. This paper introduces a novel 3-D nanostructure fabrication method by nanoimprint on silicon substrate. Nanoscale gratings and microlens array are taken as examples of 3-D nanostructures fabricated by nanoimprint. High fidelity demonstrates the possibility of nanoimprint to fabricate 3-D nanostructures on silicon substrate.

Evaluations of the hopping growth characteristics on three-dimensional nanostructure fabrication using focused ion beam

Hopping growth characteristics were examined to clarify the growth mechanism of three-dimensional nanostructures fabricated using focused-ion-beam chemical-vapor deposition (FIB-CVD). In this study, the gas density distribution of FIB-CVD was examined. As a result, a gas density has a large distribution on the vertical direction. However, the growth mechanism of a hopping nanostructure could not be explained completely. Therefore, sequential scanning ion microscope images of a hopping growth process were captured. It was found that the gap distance between the growth edges of the upper and lower structures changed during the hopping structure growth. This indicated the positional relationship between the Ga+ FIB and the growth structure. The change in this relationship induced the formation of a bridge bent structure and the change in the growth direction of the upper structure. To confirm the cause of the lower structure growth, the relationship between the Ga+ penetration depth into diamondlike carbon and the thickness of the upper structure was examined. The deposition onto the substrate was caused by the Ga+ FIB’s tail (directly irradiated beam). A hopping growth structure was formed by the repetition of these growth processes.

Highly reproducible technique for three-dimensional nanostructure fabrication via anodization scanning probe lithography

The effects of coated materials for Si probes on the sizes of line structure by using anodization scanning probe lithography (SPL) are investigated by using atomic force microscopy (AFM). Anodization SPL was carried out on the 1-decane monolayer directly attached to hydrogen-terminated silicon. Gold-coated, diamond-coated, and uncoated Si probes were used as the SPL probes in order to fabricate line structures of silicon oxide. In the cases of Au-coated and uncoated Si probes, the widths of line structures are widely influenced by the changes of scanning rate and applied bias voltage. However, the line width fabricated by use of the diamond-coated probe maintained 15 nm under any condition of scanning rate and applied bias voltage. One of the most narrow and three-dimensional nanostructures is found to be successfully fabricated on the hydrogen-terminated Si substrates when the diamond-coated probe was used as a probe of anodization SPL. In addition, this result indicated that high reproducibility of oxide nanostructures is attainable by anodization SPL used the diamond-coated probe.

Membrane stacking: A new approach for three-dimensional nanostructure fabrication

Future applications of nanotechnology, including integrated photonics, will require new three-dimensional (3D) fabrication techniques beyond those employed by the semiconductor industry. The authors investigate membrane stacking as a potential avenue for fabricating photonic crystals and other 3D structures with high yield. They fabricated membranes in silicon nitride with freestanding photonic structures and investigated the technology for stacking them.

Focused-ion-beam deposition for 3-D nanostructure fabrication

Three-dimensional nanostructure fabrication has been demonstrated by 30keV Ga+ focused-ion-beam chemical-vapor-deposition (FIB-CVD) using a phenanthrene (C14H10) source as a precursor. Microstructure plastic arts is advocated as a new field using micro-beam technology, presenting one example of micro-wine-glass with 2.75μm external diameter and 12μm height. The deposition film is a diamond like amorphous carbon. A large Young’s modulus that exceeds 600GPa seems to present great possibilities for various applications. Producing of three-dimensional nanostructure is discussed. Micro-coil, nanoelectrostatic actuator and nano-space-wiring with 0.1μm dimension are demonstrated as parts of nanomechanical system. Furthermore, filtering tool is also fabricated as a novel nano-tool for the manipulation and analysis of subcellular organelles.

Three-Dimensional Nanostructure Fabrication by Focused-Ion-Beam Chemical Vapor Deposition and Its Applications

Three-Dimensional Nanostructure Fabrication by Focused-Ion-Beam Chemical Vapor Deposition and Its Applications

Fast three-dimensional nanostructure fabrication by laser-assisted nanotransfer printing

The authors present a laser-assisted nanotransfer printing technique for transferring metal nanopatterns onto prepatterned substrates. A fused quartz mold covered with an array of chromium nanodots is pressed against the surface of a photolithographically patterned substrate, while a single laser pulse from a quadrupled-frequency solid state Nd:YAG laser is used to melt the thin metal structures. By controlling the laser fluence, selective metal pattern transfer can be realized only on the protruded area of the substrate upon separation of the quartz support. The transferred chromium nanodots are then used as an etch mask to pattern three-dimensional structures.

Three-dimensional Nanostructure Fabrication by Focused-ion-beam Chemical-vapor-deposition

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005

Three-dimensional GaN nano-structure fabrication by focused ion beam chemical vapor deposition

We have demonstrated a position controlled GaN nano-structure fabrication by ion beam mediated growth methods. For this fabrication, we used two different methods. One is the “droplet epitaxy” which is a micro-crystal growth from Ga droplet followed by nitridation. By this method, the GaN micro-crystals in about 800nm were found to be grown and cathode luminescence in broad wavelength (400–600nm) were observed. Another one is the focused ion beam assisted chemical vapor deposition. Ga precursor gas and atomic N radicals impinged onto the surface simultaneously during the irradiation. By this method, the GaN nano-crystals of 200nm×100nm block with 50nm height was fabricated and strong near-band edge emission at 3.37eV from GaN were observed. From the obtained results, ion beam assisted chemical vapor deposition proved to be a promising method to make GaN nano-crystal arrays.

Characteristics of Nano-Electrostatic Actuator Fabricated by Focused Ion Beam Chemical Vapor Deposition

The three-dimensional (3D) nanostructure fabrication technology using focused ion beam chemical vapor deposition (FIB-CVD) is very effective for highly efficient 3D nanomechanical device fabrication. We can fabricate 3D nanostructure easily and freely with this fabrication technology using FIB-CVD. Here, we demonstrate the fabrication of various 3-D nano-electrostatic actuators and manipulators on a glass capillary by 30 keV Ga+ focused-ion-beam-assisted deposition with phenanthrene vapor as a precursor, and the operation of these actuators and manipulators by applying voltage onto a Au-coated glass capillary under an optical microscope is shown. Furthermore, the structural characteristics and functionalities of them are described in this paper.

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

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

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.

Epitaxial Growth Controlled in Three Dimensions. Three-Dimensional Nanostructure Fabrication by Electron Beam Induced Surface Reactions.

Epitaxial Growth Controlled in Three Dimensions. Three-Dimensional Nanostructure Fabrication by Electron Beam Induced Surface Reactions.

The physics of vacuum microelectronic devices

Summary form only given. Vacuum microelectronics combines solid-state fabrication and processing with vacuum ballistic electronic transport. The resultant technology promises terahertz power amplifiers and oscillators, radiation hardness, subpicosecond digital switching, and temperature insensitivity in a device as small as, or smaller than, standard solid-state devices. At present vacuum microelectronic devices are based on field-emitter arrays (FEAs), which do not depend on single-crystallinity, material purity, or PN junctions. They do, however, depend on highly controlled three-dimensional nanostructure fabrication and the physics of electron transport and tunneling in those structures. Classical electron field emission has been dominated by a single parameter: the work function. Although field-emitter work functions are important in vacuum microelectronic devices, bulk nonequilibrium electron transport in fields greater than the classical breakdown field may be more important. Furthermore, emission stability might be obtainable if velocity saturation and current crowding can be incorporated into FEAs properly. Monte Carlo scattering calculations suggest a possible cause of the well-known catastrophic FEA breakdown. The same calculations point to a fundamental frequency limit in semiconductor FEA-based vacuum microelectronic devices. >