Fabrication and Characterization of Comb-Shaped Lateral Field-Emitter Arrays

A new lateral field-emitter array (FEA) has been fabricated and its structural parameters affecting the emission characteristics have been investigated. The present FEA consists of an emitter made of a tungsten thin film (0.2-0.6 µm) and a gate electrode self-aligned to the emitter with submicron spacing (0.3-0.7 µm). The emitter has an array of rectangular tips with 3-µm-wide edges; the emitter looks like a comb when viewed from above. We have measured the dependence of the emission characteristics on structural parameters such as pitch (p), emitter-to-gate spacing (g) and emitter thickness (t). It was found from experimental results that the characteristics were strongly dependent on the above parameters, especially on the p/w ratio (w is the edge width; 3 µm). An emission current of 2 µA/tip was obtained at a gate voltage of 110 V with FEA of p/w=3.3, g=0.3 µm and t=0.2 µm. In this paper, the fabrication process and emission characteristics including stability are described in detail.