Fabrication and Characterization of Silicon FEAs with Focusing Electrode by CMP Process

Abstract

We have fabricated silicon FEAs with focusing electrodes by Chemical-MechanicalPolishing (CMP) process. Afer the formation of very sharp tips, the gate electrodes were formed by CMP process. A very high etching selectivity (> lO0:l) between the gate electrode and the gate dielectric was used for preventing the tip $-om etching off during the CMP. The dishing problem during the CMP process of the gate electrode was solved by forming an oxide masking layer on the gate electrode. Afer the formation of the extracting @st) gate electrode, the second electrode for focusing the electron beam was formed. By the CMP process, a clearly cut gate electrode that exactly aligned to the tip was easily obtained. Also, the equipotential contours and electron trajectories for a single emitter that has extracting gate and focusing electrodes were simulated with a two dimensional Jinite element method.