The Effect of LaB sub 6 Cathode Shape on its Performance in a JBX 5DII Electron Beam Lithography System

The beam current and beam size at the specimen plane of a JBX 5DII electron beam lithography system was measured for various shaped, single crystal LaB sub 6 cathodes at 50 kV beam voltage. The Wehnelt aperture opening was 1.5micron and the cathode set-back was 250micron. The performance of a 90degrees full angle, conically shaped cathode with a 15micron apex radius was compared with similar cathodes having variable diameter flats at the cathode apex.