We have developed a fabrication process for isolated quantum wire structures, using advanced atomic layer epitaxy (ALE) techniques based on the self‐limiting effect. We describe several advantages of the self‐limiting effect for the fabrication process of quantum nanostructures. We also present characterizations of the quantum wire structures including photoluminescence (PL) measurements. Due to the fact that the ALE is localized on a nanometer scale and that a growth mode switching technique between isotropic and anisotropic ALE was used, well‐defined GaAs quantum wires with structure control were successfully realized. Also, quantum confinement effects of one‐dimensional systems have been observed clearly in the quantum wires via PL measurements. ©1995 American Institute of Physics.