A technique for achieving the growth of GaAs VPE layers with a highly abrupt doping profile is described. With this technique, the steepness of doping profile is remarkably improved and typical interface widths for the drop in carrier concentration from 1×1016to 1×1015cm−3are 1000 A˚. This technique also permits the growth of GaAs VPE layers with multistructure having a periodic Lo‐Hi carrier concentration profile.