Mechanisms of Difficulty to Correlate the Leakage Current of High-k Capacitor Structures with Defect States Detected Spectroscopically by the Thermally Stimulated Current Technique

Abstract

Historically, it has been difficult to correlate the leakage current of capacitor structures involving high-k dielectric materials and defect states detected spectroscopically by the thermally stimulated current (TSC) technique. Four mechanisms are proposed and solutions are explained with tantalum oxide as an example. One of the mechanisms is the limitation of the TSC technique itself because of the presence of a parasitic current due to the bias voltage used. This can be solved by migrating to more advanced versions of TSC like zero-bias TSC.

An Extended Unified Schottky-Poole-Frenkel Theory to Explain the Current-Voltage Characteristics of Thin Film Metal-Insulator-Metal Capacitors with Examples for Various High-k Dielectric Materials

“…Previously in 2011, the author points out that these two mechanisms actually can happen simultaneously and a unified Schottky-Poole-Frenkel model can be used to explain some observed experimental data. 5 The unified Schottky-Poole-Frenkel model is actually similar to a simple model involving two back-to-back Schottky diodes suggested by Lai and Lee in 1999. 6 The principal difference is the addition of a non-linear resistor RNL, which can be used to represent the Poole-Frenkel effect.…”

“…1b. J RNL = J PF [5] Lai and Lee analyzed capacitor structures involving an asdeposited tantalum oxide film which is very leaky; 6 according to the model shown in Fig. 1b, RNL is approximately zero for their work.…”

An Extended Unified Schottky-Poole-Frenkel Theory to Explain the Current-Voltage Characteristics of Capacitors Using High-k Dielectric Materials

“…The Schottky mechanism does not involve defect states in the bulk of the high-k dielectric; however, the Poole-Frenkel mechanism involves defect states in the bulk of the high-k dielectric. Previously in 2011, the author points out that these two mechanisms actually can happen simultaneously and a unified Schottky-Poole-Frenkel model can be used to explain some observed experimental data (5). The unified Schottky-Poole-Frenkel model is actually similar to a simple model involving two back-to-back Schottky diodes suggested by Lai and Lee in 1999 (6).…”

A New Mechanism of Symmetry of Current-Voltage Characteristics for High-k Dielectric Capacitor Structures

“…The author believes that quite frequently the P-F and the Schottky mechanisms happen simultaneously and so a unified Schottky-Poole-Frenkel model, as shown in Fig. 1, is quite frequently needed to explain experimental results (2). In Fig.…”