The Influence of Oxygen on Nanowire Surface Structure and Electronic Properties

Abstract: This thesis investigates the possibilities for setups measuring how the surface structure of nanowires (NWs) influences their electric properties. For this the abilities to clean surfaces and detect nanowires (NWs) are examined, and an attempt to build a setup is made. Compared to the size of NWs and surface area measured in scanning tunneling microscopy (STM), an “infinite” surface of GaAs/AlGaAs was cleaned. The method of cleaning meant using hydrogen cleaning in order to remove oxide from the surface. By the use of STM it was found that hydrogen cleaning works for such an “infinite” surface. In attempts to detect NWs the method Auger electron spectroscopy (AES) was used. The resulting spectra showed peaks from elements only found in the NWs which meant the AES works for detecting NWs. The setup built should have the ability to perform electrical measurements of a sample in vacuum while heating the sample and giving the researchers the ability to control the oxidation of the sample. A prototype of such a setup was made and its operational ability was tested in air.