Fabrication and simulation of a gated thin film emitter

Abstract

We have fabricated a gated field emitter using a diamond-like carbon ͑DLC͒ film cathode. The process involved the deposition of DLC, insulator, and gate layers followed by backetching to expose a patterned DLC. We also simulated the emission behavior of the gated DLC cathode. The emission sites on the DLC film were simulated by multiple sharp points formed on the DLC surface. The electron trajectory and the emission current were studied as a function of structural parameters such as cathode height, oxide layer thickness, gate hole diameter, and focus electrode.

Simulation of triode-type field emitters with thin-film cathodes

“…The geometrical parameters with which we carried out the numerical calculations were the gate-oxide thickness hϭ1.5 m, the gate thickness d g ϭ0.2 m, the gate-anode distance d ga ϭ60 m, and the gatehole radius rϭ6 m, respectively, and the anode-bias voltage was set at V a ϭ500 V. Note that the electric field is larger near the cathode edge than at central area; the variation of ϳ16 and ϳ21 V/m was observed over the radial distance of 6 m at V g of 45 and 60 V, respectively. 7,8 However, these approaches make the triode-fabrication process a lot more complicated, and moreover, the problem of wide spreading of emitted electrons is not alleviated, which necessitates an extra electrode to focus emitted electrons. Consequently, the emission sites located near the edge of the planar cathode contribute most of the emission cur-a͒ Author to whom correspondence should be addressed; electronic mail: soonil@ajou.ac.kr.…”

“…Electron emission from cathode surface and trajectories of field-emitted electrons were calculated using the Fowler-Nordheim field-emission equation 14 and the equation of motion, respectively. 7,8,15 Recently, we also succeeded in fabricating a triode emitter with the conventional structure using a CNP-film cathode. 10 Figure 1 shows the schematic structures of triode field emitters with planar cathodes, for which the simulations were carried out.…”

“…[1][2][3][4][5] The fabrication of triode-type field emitters based on new carbon materials has also attracted a lot of attention. [7][8][9] Recently, we successfully fabricated triode field emitters with a conventional gate structure and planar cathodes of carbon nanoparticles ͑CNPs͒, which showed relatively smooth surface morphology. However, the electric-field distributions which flat carbon-film cathodes experience are quite different from those of sharp-tip cathodes because of the geometrical difference.…”

Double-gate field emitters with planar carbon-nanoparticle cathodes: Simulation studies

“…[1][2][3][4] However, radial variation of the electric field on the planar cathode surface, which favors the electron emission near the gate edge, and wide spreading of the emitted electrons are inherent problems of the planar cathodes. [1][2][3][4] However, radial variation of the electric field on the planar cathode surface, which favors the electron emission near the gate edge, and wide spreading of the emitted electrons are inherent problems of the planar cathodes.…”

Fabrication of triode field emitter with planar carbon-nanoparticle cathode

“…[1][2][3][4][5][6][7][8] Carbon nanotubes emerged as one of the promising electron emitters due to its natural structure that could give large electric-field enhancement. Triode emitters with planar cathodes has become attractive in particular, because of the many advantages, including the substantial reduction in manufacturing cost, over tip-array cathodes.…”