Abstract: Site-controlled InAs quantum wires were fabricated with the cleaved edge overgrowth method.First,AlGaAs/GaAs superlattices were grown on GaAs substrate by molecular beam epitaxy.Then,the sample was taken out of the MBE system and cleaved along the ［110］ direction.After pretreatment,the (110) cleaved edges acted as a nanopattern in overgrowth.Experimental results demonstrate that the pretreatment on the cleaved edge affects the overgrowth and that selective etching is better than natural oxidation for site-controlled growth of quantum wires.High temperature degasification will induce pits on GaAs spacers,indicating that Ga atoms can easily escape from (110) cleaved edges.Furthermore,the surface diffusion length of Ga atoms on the (110) surface is long and the preferred diffusion direction of the atoms on (110) surface is toward ［001］.

Key words: molecular beam epitaxy, quantum wire, surface structure