Fabrication and emission properties of diode- and triode-type diamond field emitter array based on the transfer mold technique

Diode- and triode-type diamond field emitter arrays are fabricated using th e transfer mold technique and self-align process. A size-inverted pyramidal mold of micron size is formed on (100) silicon substrate using conventiona l photolithography and anisotropic etching. A diamond film thicker than 100 mu m is grown on the mold, which remains as a free-standing film of a diam ond tip array after etching the mold. Silicon dioxide and molybdenum (Mo) l ayers are deposited conformally on the diamond tip array as an insulating a nd a gate layer, respectively. A flat photo-resist (PR) layer, whose thickn ess is thinner on the tip than the surrounding area, is then coated. The un iform removal of the PR layer exposes the apex of the tips while the rest o f the surface is still covered with PR. The remaining PR layer around the t ips acts as a mask for the etching of the Mo and silicon oxide layers over the diamond tips. As a result, a diamond emitter array with a Mo gate is fa bricated. We also find that a proper treatment of the diamond tips with hyd rogen can substantially improve the emission. (C) 1999 Elsevier Science S.A , All rights reserved.