Formation of quantum wires and dots on InP(001) by As/P exchange

We report on the use of in situ scanning tunneling microscopy to study As/P exchange on InP(001) surfaces by molecular beam epitaxy. Results demonstra te that the exchange process can be controlled to selectively produce eithe r quantum wires or quantum dots. 15 nm wide self-assembled nanowires are ob served, and they are elongated along the dimer row direction of the InP(001 )-2 X 4 surface with a length of over 1 mum and flat top 2 X 4 surfaces. In addition, when the nanowires are annealed with no arsenic overpressure, th e surface reconstruction transforms from 2 X 4 to 4 X 2 and the nanowires t ransform into dots with a rectangular base and flat top. (C) 2001 American Institute of Physics.