Thermal leakage improvement by using a high-work-function ni electrode in high-kappa TiHfO metal-insulator-metal capacitors

Abstract

An unavoidable drawback when using high-kappa dielectrics in capacitors is the small bandgap and the related reduction in the band-offset, which results in a large leakage current at elevated temperatures. We report improvements in the thermal leakage current by using Ni as a high-work-function top electrode for high-kappa TiHfO capacitors. This avoids sacrificing the overall kappa value by using a multilayer or laminate structure and results in better voltage linearity, which is important for analog/radio frequency integrated circuits. (c) 2007 The Electrochemical Society.