Masaaki Hirakawa

Field emission from well-aligned, patterned, carbon nanotube emitters

We have developed a process to fabricate well-aligned, patterned, carbon nanotube field emitters on glass substrates. The process consists of depositing and patterning a nickel-based metal line on the glass substrate followed by a bias-enhanced microwave plasma chemical vapor deposition to grow carbon nanotube emitters. A turn-on field of 1.2 V/μm, and emission currents of 1 mA/cm2 at 3 V/μm were achieved on well-aligned carbon nanotube emitters. A test of cathode-ray tube lighting elements now underway suggests a lifetime of exceeding 10 000 h.

Field emission characteristics of carbon nanofiber improved by deposition of boron nitride nanocrystalline film

An improvement in field emission characteristics of a graphite nanofiber (GNF) has been attempted. Boron nitride (BN) films are synthesized by plasma-assisted chemical vapor deposition. It is demonstrated that electron emission occurs at a low anode voltage due to depositing the BN nanocrystalline film on flat Si substrates. Deposition of the BN nanocrystalline film is applied to the GNF to improve the field emission characteristics of the GNF. In addition to a reduction in the average turn-on electric field, the emission current increases by two orders of magnitude in comparison with that of an as-grown GNF.

Spin-on Cu films for ultralarge scale integrated metallization

We have developed the spin-on Cu metal (SOM) process to fill trenches and vias down to 0.3 μm. SOM is a liquid material that contains an organic solvent and dispersed ultrafine particles as a source of Cu. This solution was applied to a Si wafer using a spin coater to form a film. Coated wafers were baked at 623–673 K for 10 min in a reducing atmosphere. The end result is a Cu film. Contrary to the conventional deposition techniques, the SOM process is simple but advantageous to its gap filling, planarization, and cost consideration.

Electron field emission from boron nitride nanofilm and its application to graphite nanofiber

Hexagonal polycrystalline boron nitride (BN) films are synthesized on Si substrates by plasma assisted chemical vapor deposition. In the case of the BN films thicker than 20 nm, the turn-on electric field of the electron emission is strongly influenced by the surface roughness rather than the film thickness. On the other hand, in the case of the BN film with a thickness of 8–10 nm, it is found that the turn-on electric field as low as 8.3 V/μm is achieved in spite of the surface of the BN nanofilm being flat as well as the Si substrate. A significant reduction in the effective potential barrier height is suggested. The tunneling controlled field emission is proposed for the BN nanofilm with positive space charge. The BN nanofilm is deposited onto the graphite nanofiber sample. A significant improvement of the field emission characteristics is demonstrated.

P‐38: Nano Structure Phosphors for FEDs

Phosphor is an important element for the FED. We developed nanostructure phosphor for the FED, and tried to fabricate nano-particle and nano-thin-film phosphor. Using those phosphors, a simple panel was produced. The light emission from both nano-particle and nano-thin-film phosphor panels was confirmed.

P-39: Fabrication of a GNF-FED Using Mesh Gate

A triode graphite nanofiber FED with a mesh gate was fabricated. It was confirmed that the mesh gate has the advantage of electron divergence reduction compared with a conventional gate. The possibility of the triode FED without the forces electrode increased.

P‐123: A 4.8 inch GNF‐FED with A Mesh Gate Structure

We fabricated a color graphite nanofiber (GNF) FED with a mesh gate. The GNF-FED has a triode structure with a novel mesh gate. We confirmed that electron divergence was tightly controlled in comparison with a conventional gate structure.