Parallel multi-electron beam lithography for ic fabrication with precise x-y translation

Abstract

A maskless, direct write electron lithography apparatus for accurately and simultaneously writing plural sub-micron patterns on a silicon substrate employs plural parallel electron beams with precise X-Y mechanical translation of the substrate to provide low cost, high throughput integrated circuit (IC) fabrication. Plural compact micro electron gun assemblies arranged in an I×J rectangular grid each simultaneously expose one IC pattern on the substrate, with each electron gun assembly including a K×L array of individually controlled electron guns emitting K×L electron beams. The regular, small spacing between electron beams in each array, i.e., approximately 1 mm or less, requires a correspondingly small X-Y translation of the substrate to write the entire wafer. Each electron gun array includes plural AC blanked cathodes and DC biased plates having plural aligned beam passing apertures. A computer controlled pattern generator synchronized with wafer X-Y translation controls the duration and timing of the cathode blanking signals.