A new and simple method using device simulation results to determine the geometric dependences of the zero-bias threshold voltage and body-effect coefficient for submicrometre MOS transistors is presented. Noa priorigeometric shape of the bulk depletion region is assumed. The threshold-voltage reduction and body-effect coefficient were experimentally determined to have a linear and exponential dependence on 1/Leff, respectively, for submicrometre LDD MOS transistors with effective channel length as small as 0.22 μm.