Fabrication and characterization of silicon field emitter arrays with focusing electrode by the chemical mechanical polishing process

Abstract

We have fabricated silicon field emitter arrays with focusing electrodes by chemical mechanical polishing (CMP) process. After the formation of very sharp tips, the gate electrodes were formed by a CMP process. A very high etching selectivity (>100:1) between the gate electrode and the gate dielectric was used for preventing the tip to be etched off during the CMP. The dishing problem during the CMP process of the gate electrode was solved by forming an oxide masking layer on top of the gate electrode. After the formation of the extracting (first) gate electrode, the second electrode for focusing the electron beam was formed. By the CMP process, a clear-cut gate electrode was easily obtained which was aligned exactly to the tip. The equipotential contours and electron trajectories were simulated for a single emitter that has an extracting gate and a focusing electrode using a two-dimensional finite element method.