MULTIELECTRON BEAM BLANKING APERTURE ARRAY SYSTEM SYNAPSE-2000

A blanking aperture array (BAA) has 1024, 25-mu m-square apertures and blanking electrodes on a 20-mu m-thick Si membrane with a total apert ure ratio of 1/6. These apertures are irradiated with an electron beam , and the electrons passing through the apertures are projected onto a wafer surface in a reduction ratio of about 1 to 200. A signal applie d to each blanking electrode turns each beam on and off individually w hile raster-scanning the electron flux with a deflector; thereby the d esired pattern on the wafer can be drawn. The SYNAPSE-2000 system uses 512 beams in the center of a BAA and exposes 18 8 in. wafers per hour using a single BAA column. Large convergence semiangle, refocusing, a nd multicolumns are effective measures to reduce Coulomb interaction a nd to accomplish higher throughput. This system provides a volume-prod uction microelectronic device manufacturing method. (C) 1996 American Vacuum Society.