DC conduction properties of Gadolinium–Indium oxide films deposited on Si(1 0 0) A.A. Dakhel * Department of Physics, College of Science, University of Bahrain, Isa Town, P.O. Box 32038, Bahrain Received 28 March 2004; received in revised form 3 October 2004; accepted 17 November 2004 Available online 25 January 2005 The review of this paper was arranged by Prof. S. Cristoloveanu Abstract Thin (Gd–In) oxide films were prepared by alternating deposition method on Si (P) substrates to form MOS structures in order to investigate their dc-electrical properties. These films were annealed at different conditions and characterised by X-ray fluorescence (XRF) and X-ray diffraction (XRD). The capacitance–gate voltage (C–V g ) dependence was used to study the effect of annealing conditions on the effective relative permittivity, concentration of the charges in the film, and determination the accumulation voltage region. The dc-current transfer in the samples is studied as a function of gate voltage at accumulation polarity and temperature in the range (293–390 K). The measurements showed ohmic conduction at low voltages. But, at voltages V > 0.4 V, the current transfer followed the trap-charge-limited space-charge-limited conductivity (TCLC–SCLC) mechanism characterised by exponential distri- bution of traps within the band gap. The total traps concentrations are 4.1 · 10 24 m 3 and 2.2 · 10 24 m 3 for samples annealed in oxygen atmosphere and in vacuum, respectively. Ó 2004 Elsevier Ltd. All rights reserved. PACS: 77.55.+f; 72.20.I Keywords: Insulating films; SCLS mechanism; Gadolinium–Indium oxide; Dielectric phenomena 1. Introduction Among the wide-band-gap materials, rare earth oxi- des (REOs) have been used in production of microcir- cuit devices and sensors, as well as protective coating due to their favourable electrical, mechanical, optical properties, and chemical stability [1,3,4]. Generally, REOs are stable in contact with silicon at room temper- ature, but there is a possibility of formation of silicates during annealing at high temperatures (800–1000 °C) especially in oxygen or air atmosphere [2–5]. Most stud- ies [5–10] were focused on REOs as insulators in pure state, but the studies of composite oxides system based on REOs are seldom. Some investigations on Gd 2 O 3 (Ga 2 O 3 ) as dielectric film grown on different substrates were done by several works [11–13]. The aim of the present work is to study the dc con- duction process in the composite (Gd–In) oxides insula- tor prepared on Si substrate and the influence of the annealing conditions. We must mention that such study on (Gd–In) oxide as an insulator on Si, as far as we know, is absent from literature. 2. Experimental procedure (Gd–In) oxide thin films have been prepared by the alternating deposition of about ten layers of each of the constituent pure elements in oxygen atmosphere of 0038-1101/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.sse.2004.11.014 * Corresponding author. Tel.: +973 4499997185; fax: +973 782396. E-mail address: adakhil@sci.uob.bh www.elsevier.com/locate/sse Solid-State Electronics 49 (2005) 562–566