Improving Electrical Characteristics of Ta∕Ta[sub 2]O[sub 5]∕Ta Capacitors Using Low-Temperature Inductively Coupled N[sub 2]O Plasma Annealing

The electrical characteristics of Ta ∕ Ta 2 O 5 ∕ Ta capacitors are improved by treatments with inductively coupled N 2 O plasma. A low-temperature ( 250 ° C ) and short ( 5 min ) process was used to reduce the leakage current and improve the reliability. A low leakage current density ( 4.0 × 10 − 10 A ∕ cm 2 under 1 MV ∕ cm ), high breakdown field ( 4.2 MV ∕ cm at 10 − 6 A ∕ cm 2 ), and lifetime of over 10 years at 1.61 MV ∕ cm is obtained for the Ta ∕ Ta 2 O 5 ∕ Ta capacitor with the inductively coupled N 2 O plasma treatment. The conduction mechanism of the leakage current in the Ta ∕ Ta 2 O 5 ∕ Ta capacitor is discussed using current-voltage analyses and shows that the leakage current of the Ta ∕ Ta 2 O 5 ∕ Ta capacitor is dominated by Schottky emission. N 2 O plasma treatment can effectively reduce oxygen vacancies and the surface roughness of the Ta 2 O 5 film, inhibiting the conduction of the leakage current.