High-Performance Metal–Insulator–Metal Capacitors Using Europium Oxide as Dielectric

We report the first demonstration of metal-insulator-metal (MIM) capacitors with Eu₂O₃ dielectric for analog and DRAM applications. The influence of different anneal conditions on the electrical characteristics of the fabricated MIM capacitors is studied. FG anneal results in high capacitance density (7 fF/μm²), whereas oxygen anneal results in low quadratic voltage coefficient of capacitance (VCC) (194 ppm/V² at 100 kHz), and argon anneal results in low leakage current density (3.2 ×10^-8 A/cm² at -1 V). We correlate these electrical results with the surface chemical states of the films through X-ray photoelectron spectroscopy measurements. In particular, FG anneal and argon anneal result in sub-oxides, which modulate the electrical properties.