Patent ID: 7776760

Claim:
A method for axially doping one or more desired portions of a nanowire along a length of the nanowire during growth of said nanowire comprising: (a) providing a substrate material having one or more nucleating particles deposited thereon in a reaction chamber; (b) pre-cleaning the surface of the substrate material and the nucleating particles by introducing a pre-cleaning etchant gas into the reaction chamber; (c) after the pre-cleaning of step (b), contacting the nucleating particles with at least one precursor gas to initiate nanowire growth; (d) introducing at least one dopant gas into the reaction chamber during said nanowire growth to dope said one or more desired portions of the nanowire; and (e) during and/or prior to said dopant introduction, introducing a non-precursor etchant gas into the reaction chamber at a certain pressure, wherein the etchant gas at the certain pressure is capable of substantially minimizing uncatalysed growth resulting from the at least one precursor gas on a sidewall of the nanowire during said nanowire growth and hindering incorporation of the at least one dopant on a sidewall of the nanowire.