Multielectron beam blanking aperture array system SYNAPSE‐2000

A blanking aperture array (BAA) has 1024, 25‐μm‐square apertures and blanking electrodes on a 20‐μm‐thick Si membrane with a total aperture 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 applied to each blanking electrode turns each beam on and off individually while raster‐scanning the electron flux with a deflector; thereby the desired 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, and multicolumns are effective measures to reduce Coulomb interaction and to accomplish higher throughput. This system provides a volume‐production microelectronic device manufacturing method.