Fabrication of einzel lens array with one-mask reactive ion etching process for electron micro-optics

In this paper, we report the fabrication of electron micro-optics by using deep reactive ion etching of three stacked silicon wafers. The three 120-μm-thick silicon wafers stacked with cavities are etched by a direct cavity through etching technique, where each wafer is bonded with a 200-μm-thick glass with through holes, thus separated by a space in part. An array of the electron micro-optics consisting of three electrodes can be fabricated by a one-mask process without assembling and alignment process. The dimensional profiles of a sample etched using this technique are also investigated. This micro-optics fabrication technology is useful for making future multiple electron beam devices with electron optics.