We study the effect of thermal annealing on the electrical properties of the nanoscale p-n heterojunctions based on single n-type ZnO nanorods on p-type GaN substrates. The ZnO nanorods are prepared by chemical bath deposition on both plain GaN substrates and on the substrates locally patterned by focused ion beam lithography. Electrical properties of single nanorod heterojunctions are measured with a nanoprobe in the vacuum chamber of a scanning electron microscope. The focused ion beam lithography provides a uniform nucleation of ZnO, which results in a uniform growth of ZnO nanorods. The specific configuration of the interface between the ZnO nanorods and GaN substrate created by the focused ion beam suppresses the surface leakage current and improves the current-voltage characteristics. Further improvement of the electrical characteristics is achieved by annealing of the structures in nitrogen, which limits the defect-mediated leakage current and increases the carrier injection efficiency.
AbstractNi nanowires were fabricated by electrochemical deposition in the pores of alumina filtration membranes, with the diameter around 200nm. To study the magnetic and electrical properties of Ni nanowires, individual nanowire was selected and connected with metal electrodes. Single and multiple constrictions were formed on the nanowires by focused ion beam (FIB). The wires were further thinned using oxygen plasma oxidation. Magnetoresistance curves were studied and compared before and after FIB trimming and oxidization.
Abstract
We have demonstrated the sample fabrication by focused ion beam (FIB) milling and delineation etch gas which makes it possible to directly measure resistance in a cross section of semiconductor devices with a nano probe after cell fabrication. With direct evaluation of electrical properties, this technique can help improve semiconductor devices.
Focused ion beam (FIB) is an important tool in microfabrication technique. In recent years, FIB was used to fabricate the nanodevices. In this paper, Pt nanowires with differ radius were deposited with FIB. The component and resistance of nanowires were investigated. Results indicate that the component of Pt naowires is mainly Pt, C and Ga. The high content of Pt in nanowires is 49.36%. The resistivity of Pt nanowire is from 545.74µΩ•cm to 5.16µΩ•cm. Pt nanowires with the diameter up to 60nm take on characteristic of metal; others take on that of semiconductor.
AbstractThe use of focused and broad beam Ga+ implantation for the fabrication of p+-n Si shallow junctions is explored. In particular, the issue of ion induced damage and its effect on diode electrical properties is explored. FIB-fabricated junctions exhibit a deeper junction with lower sheet resistance and higher leakage current than the BB-implanted diodes. TEM analysis exhibits similar amorphization and recrystallization behavior for both implantation techniques with the BB case generating a higher dislocation loop density after a 900°C anneal.
Highly Rectifying Heterojunctions Formed by Annealed ZnO Nanorods on GaN Substrates