A New Cost-Effective Metal–Insulator–Metal Capacitor Processed at 350 ∘C Using Ni₂Si Fully Silicided Amorphous Silicon Electrodes

Without requiring noble metal materials, a novel low-cost Ni2Si/TiO2/Ni2Si metal-insulator-metal (MIM) capac itor processed at 350°C has been developed using nickel fully sili cided (Ni-FUSI) amorphous silicon electrodes. A high capacitance density of 17 fF/μm2along with a low top-electrode resistivity of ~38 μΩ · cm were achieved. At 25°C, this MIM capacitor also displays a good leakage current density of 6.4 × 10-6A/cm2at -1 MV/cm (-2.5 V) and a quadratic voltage coefficient a of 4110 ppm/V2. Schottky emission dominates the leakage current in low negative field (;1.4 MV/cm). The Schottky barrier height ΦBat the Ni2Si/TiO2interface was first extracted to be 0.8 eV, whereas the trap barrier height Φt in the TiO2film was 0.39 eV. Material characterization further reveals that this structure is highly appropriate for future ultralarge-scale-integration technologies.