Improving electrical characteristics of Ta Ta2 O5 Ta capacitors using low-temperature inductively coupled N2 O plasma annealing

The electrical characteristics of Ta Ta2 O5 Ta capacitors are improved by treatments with inductively coupled N2 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 cm2 under 1 MVcm), high breakdown field (4.2 MVcm at 10-6 A cm2), and lifetime of over 10 years at 1.61 MVcm is obtained for the Ta Ta2 O5 Ta capacitor with the inductively coupled N2 O plasma treatment. The conduction mechanism of the leakage current in the Ta Ta2 O5 Ta capacitor is discussed using current-voltage analyses and shows that the leakage current of the Ta Ta2 O5 Ta capacitor is dominated by Schottky emission. N2 O plasma treatment can effectively reduce oxygen vacancies and the surface roughness of the Ta2 O5 film, inhibiting the conduction of the leakage current.