Dielectric relaxation and defect analysis of Ta₂O₅thin films

Abstract

The presence of defects in thin-film dielectrics often leads to dielectric relaxation as a function of frequency, in which the dielectric constant decreases and the loss tangent increases with increasing frequency. Dielectric relaxation results in charge storage capacity reduction under dynamic random access memory operating conditions. In this work, the dielectric relaxation behaviour of dc reactive sputtered Ta2O5 thin film was investigated. Using dielectric dispersion measurements as a function of frequency (100 Hz⩽f⩽10 MHz) and temperature (27 °C⩽T⩽150 °C), we determined the dielectric relaxation and defect quantity of the films and propose an equivalent circuit on the basis of complex capacitance, admittance and impedance spectral studies.

Deposition and Properties of the Pseudobinary Alloy (Al2O3)x(TiO2)1-x and Its Application for Silicon Surface Passivation

“…The capacitance dispersion as a function of frequency may be due to grain boundary defects, which lead to dielectric relaxation as a function of frequency. 19) The effect of frequency is similar to that of high-k dielectric layers. Table IV gives the relative dielectric constant of PBA films 120 nm thick.…”

Single Layer Polycrystalline ZnO–Al<SUB>2</SUB>O<SUB>3</SUB> Nanocomposite Thin Films: Optical and Electrical Properties

“…12 On the other hand, the frequency dependent electrical properties of the thin film greatly depends on the structural homogeneity and stability of the composite based devices and can highlight the relative contribution of the grain, grain boundary, and the defect states to the total ac response under a given set of experimental condition. [13][14][15] This investigation explains the dielectric properties of the ZnO-Al 2 O 3 nanocomposite thin films with high optical transparency prepared by sol gel technique. In some previous reports 16 17 the role of grain and grain boundary in the electrical properties of undoped ZnO and doped (with Al +3 , Ag +2 ) nanocomposites were studied.…”

Frequency Dependence of C-V Characteristics of MOS Capacitors Containing Nanosized High-κ Ta2O5 Dielectrics

“…In the case of leaky and high-dielectrics, measurements in parallel mode have many disadvantages. A three-element model, including an additional serial resistance, was used to describe frequency dependence of the measured capacitance [20,21]. In the case of high leakage thin dielectrics, it was observed that the C-V characteristics measured at higher frequencies are unrealistic; the measured capacitance decreases with the frequency and the gate voltage.…”