The effect of electron beam acceleration voltage and beam sharpness upon process latitudes of 0.2 micrometers line fabrication is estimated by computer simulation. Process latitude refers to dose and development time latitudes whereby the proper resist profiles are obtained. The latitudes are compared for acceleration voltages of 30 and 50 keV; beam blurs of 0.0, 0.05, and 0.1 micrometers ; resist patterns on bare Si and on Si covered with W layer; and three categorized exposed pattern with different pattern densities. in the case of the bare Si substrate, even beams at 30 keV acceleration with 0.1 micrometers beam blur give proper process latitudes. Thus, the 0.2 micrometers lines can be fabricated at 30 keV acceleration with 0.1 micrometers beam blur. On the contrary, for the resist patterns on W layer, 50 keV is necessary. Moreover, in the case of the bare Si substrate, the higher acceleration voltage made the process latitude larger at each categorized pattern. However, for reducing proximity effects between different categorized patters, a sharper beam blur is more effective than a higher acceleration voltage.