Superlattice structures made by molecular beam epitaxy are profiled by a combined technique of argon sputter etching and Auger electron spectroscopy. The superlattice, consisting of periodic layers of 50‐Å GaAs and Ga1−xAlxAs, probably represents the structure with the shortest period ever made and analyzed in monocrystalline semiconductors. Also established is the dependence of the intensity ratio of aluminum to arsenic signals of Auger transitions on the aluminum composition in Ga1−xAlxAs.