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

An unavoidable drawback when using high- κ 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- κ TiHfO capacitors. This avoids sacrificing the overall κ value by using a multilayer or laminate structure and results in better voltage linearity, which is important for analog/radio frequency integrated circuits.