Stability of La2O3 Metal-Insulator-Metal Capacitors under Constant Voltage Stress

Abstract

In this study, we demonstrate the stability of high-kappa La2O3 metal-insulator-metal (MIM) capacitors under constant voltage stress (CVS). It was found that the variation in capacitance caused by CVS strongly depends on the injected charges regardless of stress biases. Furthermore, the quadratic voltage coefficient of capacitance (alpha) decreases with a logarithmic increase in dielectric loss. Charge trapping contributes to the relative capacitance variation under CVS while the reduced carrier mobility due to the stress-induced traps is responsible for the reduction of alpha. Additionally, high stability of 10-year lifetime is achieved for a 10-nm La2O3 MIM capacitor with an 11.4 fF/mu m(2) capacitance density. (C) 2010 The Japan Society of Applied Physics