In-situ STM-TEM Studies of Individual GaN Nanowires

The electronic and structural properties of individual GaN nanowires were studied using a scanning tunneling microscopy (STM) stage that operates inside a high-resolution transmission electron microscope (TEM) allowing simultaneous evaluation of electrical, compositional, and structural properties with nm-scale resolution. The GaN nanowires were prepared by atmospheric CVD on SiO$_{2}$/Si substrates. Catalyst metal deposition consisted of electron-beam lithography patterned Ni dots, enabling diameter- and position-controlled nanowire growth for device-compatible processing. A focused ion beam- scanning electron microscope with an in situ micromanipulator was used to extract single GaN nanowires from the substrate and attach them to copper TEM supports. Analysis of I-V characteristics of individual wires, and any correlation with microstructure, such as wire dimensions, growth habit and defect concentration will be presented.