title: Investigation of III-V nanowires by plan-view transmission electron microscopy: InN case study.
abstract: We discuss observations of InN nanowires (NWs) by plan-view high-resolution transmission electron microscopy (TEM). The main difficulties arise from suitable methods available for plan-view specimen preparation. We explore different approaches and find that the best results are obtained using a refined preparation method based on the conventional procedure for plan-view TEM of thin films, specifically modified for the NW morphology. The fundamental aspects of such a preparation are the initial mechanical stabilization of the NWs and the minimization of the ion-milling process after dimpling the samples until perforation. The combined analysis by plan-view and cross-sectional TEM of the NWs allows determination of the degree of strain relaxation and reveals the formation of an unintentional shell layer (2-3-nm thick) around the InN NWs. The shell layer is composed of bcc In2O3 nanocrystals with a preferred orientation with respect to the wurtzite InN: In2O3 [111] || InN [0001] and In2O3<110>||InN<1120>.
authors.affiliation: 1Paul-Drude-Institut für Festkörperelektronik,Hausvogteiplatz 5-7,D-10117 Berlin,Germany.
authors.forename: Esperanza
authors.initials: E
authors.lastname: Luna
authors.affiliation: 1Paul-Drude-Institut für Festkörperelektronik,Hausvogteiplatz 5-7,D-10117 Berlin,Germany.
authors.forename: Javier
authors.initials: J
authors.lastname: Grandal
authors.affiliation: 1Paul-Drude-Institut für Festkörperelektronik,Hausvogteiplatz 5-7,D-10117 Berlin,Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Gallardo
authors.affiliation: 2Departamento de Física de Materiales,Universidad Autónoma de Madrid,E-28049 Madrid,Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Calleja
authors.affiliation: 3ISOM and Departamento Ingeniería Electrónica,ETSI Telecomunicación,Universidad Politécnica de Madrid,E-28040 Madrid,Spain.
authors.forename: Miguel Á
authors.initials: MÁ
authors.lastname: Sánchez-García
authors.affiliation: 3ISOM and Departamento Ingeniería Electrónica,ETSI Telecomunicación,Universidad Politécnica de Madrid,E-28040 Madrid,Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Calleja
authors.affiliation: 1Paul-Drude-Institut für Festkörperelektronik,Hausvogteiplatz 5-7,D-10117 Berlin,Germany.
authors.forename: Achim
authors.initials: A
authors.lastname: Trampert
mesh_terms: D007204:Indium; D046529:Microscopy, Electron, Transmission; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure*
chemical_list: D007204:Indium; C513701:indium nitride