Analysis of reliability characteristics of high capacitance density MIM capacitors with SiO2-HfO2-SiO2 dielectrics

In this paper, reliability as well as electrical properties of high capacitance density metal-insulator-metal (MIM) capacitor with hafnium-based dielectric is analyzed in depth. The fabricated MIM capacitor exhibits not only high capacitance density but also low voltage coefficient of capacitance (VCC) and low temperature coefficient of capacitance (TCC). It also has a low leakage current level of about ~1nA/cm^2 at room temperature and 1V. However, it is shown that voltage linearity has a different dependence on the polarity of applied bias as temperature increases maybe due to the bulk traps between the metal electrode and high-k dielectric interface. In addition, the effect of charge trapping and de-trapping on the voltage linearity is analyzed under constant voltage stress.