Integrated high-κ (κ ∼ 19) MIM capacitor with Cu/ low-κ interconnects for RF application

Abstract

We demonstrate a high-performance metal-high κ insulator-metal (MIM) capacitor integrated with a Cu/low-κ backend interconnection. The high-κ used was laminated HfO2-Al 2O3 with effective κ ∼ 19 and the low-κ dielectric used was Black Diamond with κ ∼ 2.9. The MIM capacitor (∼ 13.4 fF/μm2) achieved a Q-factor ∼ 53 at 2.5 GHz and 11.7 pF. The resonant frequency fr was 21% higher in comparison to an equivalently integrated Si3N4-MIM capacitor (∼ 0.93 fF/μm2) having similar capacitance 11.2 pF. The impacts of high-κ insulator and low-κ interconnect dielectric on the mechanism for resonant frequency improvement are distinguished using equivalent circuit analysis. This letter suggests that integrated high-κ MIM could be a promising alternative capacitor structure for future high-performance RF applications. © 2005 IEEE.