Fabrication of GaAs quantum wires by natural selective doping and its characterization by electrostatic force microscope

We report an in situ fabrication method of self-organized quantum wire stru ctures on patterned GaAs substrates by molecular beam epitaxy. The present method is based upon a selective doping mechanism of amphoteric silicon dop ant both on patterned (311)A and on (100) GaAs substrates. The surface elec trostatic potential distribution on these patterns was investigated by elec trostatic force microscope (EFM) and quantum wire structures were verified. A minimum wire width of approximate to 80 nm was obtained for samples base d on both substrate orientations. Good agreement of the wire width estimati on by the EFM estimation and the magnetoresistance measurement on modulatio n-doped heterojunction single quantum wire transistor confirms the validity of the present approach to fabricate self-assembled quantum wires. (C) 200 0 American Vacuum Society.