Electrical Characterization of Metal--Insulator--Metal Capacitors with Atomic-Layer-Deposited HfO₂ Dielectrics for Radio Frequency Integrated Circuit Application

Metal--insulator--metal (MIM) capacitors with atomic-layer-deposited HfO₂ dielectric and TaN electrodes are investigated for rf integrated circuit applications. For 12nm HfO₂, the fabricated capacitor exhibits a high capacitance density of 15.5fF/μm² at 100kHz, a small leakage current density of 6.4×10^-9A/cm² at 1.8\,V and 125°C, a breakdown electric field of 2.6MV/cm as well as voltage coefficients of capacitance (VCCs) of 2110ppm/V² and -824ppm/V at 100kHz. Further, it is deduced that the conduction mechanism in the high field range is dominated by the Poole--Frenkel emission, and the conduction mechanism in the low field range is possibly related to trap-assisted tunnelling. Finally, comparison of various HfO₂ MIM capacitors is present, suggesting that the present MIM capacitor is a promising candidate for future rf integrated circuit application.