Data processing system of electron-beam lithography for VLSI microfabrication

A data processing system called Automatic Masking-Data generation for Electron-beam exposure System (AMDES) for drawing submicrometer patterns of integrated circuits has been developed. Electron-beam exposure data are generated based on the mask pattern design data. Distortion of patterns due to electron-beam deflection is compensated for by analyzing the inverse-mapping of the distortion function. Furthermore, a method of compensating for distortion due to the proximity effect is proposed. This method applies to multiple integral of the exposure intensity distribution (EID) function around the characteristic length neighborhood of the representative point. Computing algorithms have also been proposed to handle arbitrarily shaped pattern data to remove overlapping, which causes multiple exposure, to invert polarity of mask patterns that produce negative exposure patterns, and to partition patterns into subfields whose domains are limited by the scanning angle of the electron-beam equipments. By using this system with 1-µm design rule, a highly integrated resist pattern was produced by directly exposing an electron beam onto the wafer.