Development and characterization of metal-insulator-metal capacitors with SiN_x thin films by plasma-enhanced chemical vapor deposition

We report the fabrication of high breakdown voltage metal-insulator-metal (MIM) capacitors with 200-nm silicon nitride deposited by plasma-enhanced chemical vapor deposition with 0.957 SiH₄/NH₃ gas mixing rate, 0.9 Torr working pressure, and 60W rf power at 250°C chamber temperature. Some optimized mechanisms such as metal source wiping, pre-melting and evaporation rate adjustment are used for increasing the yield of the MIM capacitors. N₂ annealing and O₂/H₂ plasma pre-deposition treatment is proposed to increase the reliability of the MIM capacitors in high-temperature, high-pressure, and high-humidity environments. A 97% yield and up to 148V breakdown voltage of a 13.06 pF MIM capacitor with 0.04 mm² die area can be fabricated.