Dynamic space charge effect correction in cell projection lithography

A system of dynamic space charge effect correction for cell projection lithography has been developed. In cell projection lithography, higher currents are used than in conventional variable shaped beam lithography for very fine LSI patterns. Thus, beam blurring due to Coulomb effects is very important. The features of the correction system are as follows: (1) dynamic refocusing according to beam current through cell apertures, (2) dynamic deflection distortion correction according to beam current and (3) auto beam alignment through cell apertures. As a result, cell patterns are successfully delineated with dynamic space charge effect correction.