The electrostatic potential and the carrier distribution in periodically line‐doped structures are calculated within the semiclassical approximation. When the distance between the doped lines is 8 nm, which is a typical periodicity experimentally realized on the (100) GaAs surface, the system is regarded as a lateral superlattice instead of parallel wires because of strong overlap of the electron charge. Moreover, the modulation is anticipated not to be sufficient to probe the electronic state unambiguously. Alternative possible structures to enhance the modulation, which may provide more suitable systems for experiments, are investigated. It is shown that the confinement is stronger for heavier carriers by virtue of their smaller screening length. The coupling among the wires is suppressed by inserting weakp‐type dopant lines in between the channels. An application of the line doping to a heterojunction is also examined. ©1995 American Institute of Physics.