DC conduction properties of oxidised erbium films deposited on Si(1 0 0) substrates

• Published in: Journal of alloys and compounds Vol. 396; no. 1; pp. 74 - 78
• Main Author: Dakhel, A.A.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 21.06.2005; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric breakdown and space-charge effects; Dielectric phenomena; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Erbium oxide; Exact sciences and technology; Insulating films; Metal-insulator-semiconductor structures (including semiconductor-to-insulator); Physics; SCLC mechanism; 77.55.+f; Insulating films; Erbium oxide; Dielectric phenomena; 72.20.−I; SCLC mechanism; Voltage dependence; Annealing; Electrical conductivity; Phase transformations; 72.20.-I Insulating films; MOS structure; Electron charge distribution; t-J model; XRD; Thin films; Charge density; Traps; Silicon oxides; Capacitance; Oxidation; IV characteristic; Erbium
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2005.01.007

Thin Er-oxide films were prepared by oxidation of pure Er films grown on Si(P) substrates. The oxide films were annealed at different conditions and characterised by X-ray diffraction (XRD). The correlation between structural changes due to the annealing and insulating properties was studied. The constructed Al/Er oxide/Si MOS devices were characterised by measuring their capacitance dependence on gate-voltage, from which the density of charges in the oxide were determined. The dc-electrical conduction of the (Er oxide–silicon) structure was studied at room temperature and temperature range of 295–385 K. Current–voltage J( V g) and current–temperature J( T) characteristics were analysed, observing that they referred to different current-transfer processes depending on their annealing conditions i.e. on their structure and trap concentration. The current transfer in the oxide film annealed in dry oxygen was governed by the Richardson–Schottky (RS) mechanism while in the oxide film annealed in vacuum was ruled by the trap–charge-limited–space–charge-limited conductivity (TCLC–SCLC) mechanism characterised by exponential distribution of traps. This change of current-transfer mechanism is attributed to the creation of more oxygen vacancies (traps) as a consequence of annealing in vacuum. However, the parameters of the above mechanisms were determined.