A New Cost-Effective Metal–Insulator–Metal Capacitor Processed at 350 $^{\circ}\hbox{C}$ Using $ \hbox{Ni}_{2}\hbox{Si}$ Fully Silicided Amorphous Silicon Electrodes

Without requiring noble metal materials, a novel low-cost Ni
₂
Si/TiO
₂
/Ni
₂
Si 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/μm
²
along 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
^-6
A/cm
²
at -1 MV/cm (-2.5 V) and a quadratic voltage coefficient a of 4110 ppm/V
²
. Schottky emission dominates the leakage current in low negative field (<;1 MV/cm), whereas Poole-Frenkel effect appears in high negative field (>;1.4 MV/cm). The Schottky barrier height Φ
_B
at the Ni
₂
Si/TiO
₂
interface was first extracted to be 0.8 eV, whereas the trap barrier height Φt in the TiO
₂
film was 0.39 eV. Material characterization further reveals that this structure is highly appropriate for future ultralarge-scale-integration technologies.