Characterization and Modeling of Voltage and Temperature Dependence of Capacitance in Al2O3-Laminated Ta2O5 Metal–Insulator–Metal Capacitor

Abstract

Metal–insulator–metal (MIM) capacitors with Al2O3-laminated Ta2O5 insulators are fabricated and characterized in terms of voltage linearity and temperature linearity. Voltage dependence of capacitance in the laminated capacitor is dominated by the capacitance change in the Al2O3 layer. Therefore, the voltage-linearity coefficients of the laminated capacitor can be predicted using the coefficient of the single-layer Al2O3 capacitor and the effective oxide thickness (EOT) of the laminated capacitor. Moreover, the temperature coefficient of capacitance (TCC) is not dominated by an interface characteristic, but by a bulk characteristic of the insulators. We propose a model that the TCC of the laminated capacitor can be given by a linear combination of the TCC of each insulator and its EOT ratio. The model has been validated by experimental data.