This article evaluates the impact of shot noise on electron beam direct write lithography process for sub-45-nm back end of the line (BEOL) structures on process window and line edge roughness. Several parameters such as resist sensitivity and pattern density are investigated to determine their influence on shot noise. This study highlights recommendations and technological solutions to reduce shot noise issue and discusses the specifications of the electron beam resist sensitivity for next generation nodes. Finally, a realization of 45 nm BEOL structures is presented with electrical measurements done after achieving a full-integration process. (c) 2007 American Vacuum Society.