Monte Carlo calculations, including secondary electron generation and development simulation, using a string algorithm have been carried out in order to estimate the process capabilities for a beam voltage of 50 keV with a rectangular shaped beam in electron beam lithography technology. The results for minimum resolution for the threshold energy density model and the development model were compared. A study of minimum resolution and process latitude with respect to the acceleration voltage, resist thickness, beam blur for commercial PBS resist was investigated. In addition, at 50 keV, the effects of (alpha) value, asymptotic slope at very high dose in the dissolution rate equation on minimum resolution and process latitude were examined. The results show that it is necessary to use resist with a higher (alpha) value, as well as a high acceleration voltage of 50 keV, in order to enhance process capabilities.