In this paper, electrical properties and reliability of high capacitance density Metal-Insulator-Metal (MIM) capacitor with sandwiched hafnium-based dielectric is analyzed using three kinds of voltage stress; constant voltage stress (CVS), unipolar voltage and bipolar voltage stresses. The fabricated MIM capacitor shows not only high capacitance density but also low leakage current density of about similar to 10 nA/cm(2) at room temperature and 1 V. The relative variation of capacitance (Delta C/C-0) increases and the variation of voltage linearity (alpha/alpha(0)) gradually decreases with stress-time due to the charge trapping effect in the high-k dielectric. The relative variations of capacitance and voltage linearity show the greater change by the bipolar voltage stress than CVS and unipolar voltage stresses. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.