title: Electrical and Surface Properties of InAs/InSb Nanowires Cleaned by Atomic Hydrogen.
abstract: We present a study of InAs/InSb heterostructured nanowires by X-ray photoemission spectroscopy (XPS), scanning tunneling microscopy (STM), and in-vacuum electrical measurements. Starting with pristine nanowires covered only by the native oxide formed through exposure to ambient air, we investigate the effect of atomic hydrogen cleaning on the surface chemistry and electrical performance. We find that clean and unreconstructed nanowire surfaces can be obtained simultaneously for both InSb and InAs by heating to 380 ± 20 °C under an H2 pressure 2 × 10(-6) mbar. Through electrical measurement of individual nanowires, we observe an increase in conductivity of 2 orders of magnitude by atomic hydrogen cleaning, which we relate through theoretical simulation to the contact-nanowire junction and nanowire surface Fermi level pinning. Our study demonstrates the significant potential of atomic hydrogen cleaning regarding device fabrication when high quality contacts or complete control of the surface structure is required. As hydrogen cleaning has recently been shown to work for many different types of III-V nanowires, our findings should be applicable far beyond the present materials system.
authors.affiliation: †Division of Synchrotron Radiation Research, Lund University, Lund 221 00, Sweden.
authors.forename: James L
authors.initials: JL
authors.lastname: Webb
authors.affiliation: †Division of Synchrotron Radiation Research, Lund University, Lund 221 00, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Knutsson
authors.affiliation: †Division of Synchrotron Radiation Research, Lund University, Lund 221 00, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Hjort
authors.affiliation: ‡Division of Solid State Physics, Lund University, Lund 221 00, Sweden.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Gorji Ghalamestani
authors.affiliation: ‡Division of Solid State Physics, Lund University, Lund 221 00, Sweden.|§Center for Analysis and Synthesis, Lund University, Lund 221 00, Sweden.
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Dick
authors.affiliation: †Division of Synchrotron Radiation Research, Lund University, Lund 221 00, Sweden.
authors.forename: Rainer
authors.initials: R
authors.lastname: Timm
authors.affiliation: †Division of Synchrotron Radiation Research, Lund University, Lund 221 00, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Mikkelsen
keywords: III−V; InAs; InSb; STM; heterostructure; nanowire