EXPERIMENTAL EVALUATION OF AN ELECTRON-BEAM PULSE-MODULATED BLANKER (160 MHZ) FOR NEXT-GENERATION ELECTRON-BEAM RASTER SCAN SYSTEMS

The simplicity of raster scan architecture has several benefits for ma sk-making production tools, the most important being accuracy. Neverth eless, building patterns on a grid resolution determined by the writin g address of the raster scan mask generator places limitations on patt ern edge locations, or equivalently, on throughput A method of getting around this throughput bottleneck is pixel-level dose modulation, i.e ., graybeam. In this article, a new driver technology in combination w ith the MEBES (R) 4500 blanker operating at 160 MHz is experimentally evaluated for real-time dose modulation by pulse width variation. Meas urements of the rise and fall time of the blanker driver using various input data vectors (i.e., combinations of various pulse width signals ) and a beam current modulation transfer function for the blanker are presented. Contributions from electronic artifacts such as electronic jitter are measured. Finally, these measurement results are used to de termine the preliminary performance of a graybeam system. (C) 1995 Ame rican Vacuum Society.