All electrostatic electron optical sub-system for variable electron beam spot shaping and method of operation

摘要

An all-electrostatic variable spot charged particle (electron) beam shaping sub-system which is compact and of much smaller size than known similar systems designed for the same purpose and operating with magnetic lenses. The improved electrostatic variable spot-shaping sub-system does not require mechanical rotation of the spot-shaping apertures for maintaining alignment or orientation. The improved sub-system includes both beam steering and beam blanking requiring less than 3 volts for operation of the blanking controls to turn the beam on and off. The novel system easily accomodates a variety of different beam-shaping apertures for use as the second beam shaping aperture in the sub-system including rectilinear triangles of different orientation to provide smooth 45 degree pattern delineation, rectangles, squares, and even different diameter circles where such configurations are required by a particular pattern to be written in the target plane.