Patent ID: 8173978

Claim:
A method for controlling electron beams in a multi-microcolumn, in which unit microcolumns comprising an emitter and one or more electron lenses which include two or more lens layers and one or more deflectors for emitting electrons to form and control the electron beams are arranged in an n×m matrix, the method comprising the steps of: applying a voltage to the individual electron emitters according to a first or second type and applying a voltage to individual extractors of the lens according to the first or second type in order to induce emission and electron current, without applying voltages to both the electron emitters and the extractors according to the first type simultaneously; applying a voltage to an electron lens which includes two or more lens layers according to the first type and the second type; and applying a voltage according to a third type to deflect the electron beams after applying a voltage to a lens layer according to the first type, wherein the first type applies a single voltage to all apertures through which the electrons of the unit microcolumns pass or to all the electron emitters, the second type applies individual voltages to individual apertures or electron emitters of each unit microcolumn, and the third type applies the same voltage to each same-directional electrode per unit microcolumn.