Charge storage behavior of nanostructures based on SiGe nanocrystals embedded in Al2O3 matrix

• Published in: The European physical journal. B, Condensed matter physics Condensed matter physics, 2013-07, Vol.86 (7), Article 336
• Main Authors: Vieira, Eliana M. F., Levichev, Sergey, Dias, Carlos J., Igreja, Rui, Buljan, Maja, Bernstorff, Sigrid, Conde, Olinda, Chahboun, Adil, Rolo, Anabela G., Gomes, Maria J. M.
• Format: Article
• Language: English
• Subjects: Complex Systems; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Fluid- and Aerodynamics; Nanocrystalline materials; Physics; Physics and Astronomy; Regular Article; Solid State Physics
• ISSN: 1434-6028; 1434-6036
• DOI: 10.1140/epjb/e2013-40124-2

The charge storage behavior of nanostructures based on Si 1− x Ge x (0 ≤ x ≤ 1) nanocrystals (NCs) in an Al 2 O 3 matrix was investigated. The structures have been grown by RF magnetron sputtering and subsequently annealed at temperatures ranging from 700 °C to 1000 °C for 30 min in nitrogen ambient. The stoichiometry of the SiGe NCs and the alumina crystalline structure were found to be significantly dependent on the RF power and the annealing temperature. The sizes of the SiGe NCs and their distribution were investigated by grazing incidence small angle X-ray scattering (GISAXS). The capacitance-voltage ( C - V ) and conductance-voltage ( G - V ) measurements were performed to investigate the charge trapping characteristics of the memory structures. The C - V hysteresis width depends on variations in the crystalline structure resulting from different annealing temperatures. It is also shown that charge injection is governed by the Fowler-Nordheim tunnel mechanism for higher electric fields.