Carbon nanotube on a Si tip for electron field emitter

In this letter, the results of selective growth and electron field emission characterization of an individual carbon nanotube on a Si tip are presented. An individual, multiwall carbon nanotube was grown vertically at the apex of a microfabricated Si tip using hot-filament chemical vapor deposition with a mixture of C₂H₂ and H₂ gases. During the growth process, an electrical filed of 5 × 10⁴ V/m was applied between the Si tip and a filament to electrically enhance the growth of the carbon nanotube from the apex of the tip. The carbon nanotube with a diameter of 4-25 nm and a length of 300-400 nm was vertically aligned from the apex of the Si tip. Electron field emission characteristics of the single Si tip with and without the individual carbon nanotube on the same substrate were measured at room temperature in a vacuum of 1.7 × 10^-4 Pa. The threshold voltages were approximately 40 V (4 V/μm) and 200 V (20 V/μm) for the Si tips with and without the carbon nanotube, respectively.