Highly uniform silicon field emitter arrays fabricated using a trilevel resist process

The authors report silicon field emitter arrays (FEAs) that were fabricated using a trilevel resist process and are highly uniform. The authors explored the current sensitivity of FEAs to tip radius variation using different tip radius distributions and show that reducing the tip radius dispersion is an effective alternative to increasing the resistance of a current limiter for achieving uniform emission current. In order to reduce the tip radius dispersion, the authors use a trilevel resist process to increase the uniformity of the array of dots used as the etching mask for forming the silicon tips. SEM images show that they were able to reduce the standard deviation of the dot diameter by 60% using a trilevel resist process instead of a single layer resist process. Device characterization showed that the FEAs have a very narrow range of slopes, $bFN$⁠, extracted from the Fowler–Nordheim plot, indicating that the field emitters within the FEA are highly uniform.