The stochastic Coulomb interaction effect in positive ion-neutralized electron-beam (e-beam) projection optics was investigated using Monte Carlo simulations. Stationary ions in the projection optics neutralize e-beam space charge without causing an unwanted increase in stochastic blur. The Coulomb interaction due to the stationary positive ions only has an effect as that of a continuum space charge. We also found that asymmetric point spreads at the field corners are due to the stochastic Coulomb interaction effect and are not a result of residual space charge effect. Methods of ion cloud generation were preliminary discussed. The ion neutralization potentially increases the throughput of an exemplary electron projection tool for 30 nm devices by a factor of 2.