A new post-deposition annealing method using furnace N/sub 2/O for the reduction of leakage current of CVD Ta/sub 2/O/sub 5/ storage capacitors

In this work, we present a new post-deposition annealing technique that employs furnace annealing in N/sub 2/O (FN/sub O/) to reduce the leakage current of CVD Ta/sub 2/O/sub 5/ thin films. The decrease in leakage current can be attributed to the reduction of oxygen vacancies by the atomic oxygen species generated from the dissociation of N/sub 2/O at high temperatures. Compared with furnace annealing in O/sub 2/(FO) and rapid thermal annealing in N/sub 2/O (RTN/sub 2/O), FN/sub 2/O annealing proved to have the lowest leakage current and the most reliable time-dependent dielectric breakdown (TDDB). Moreover, FN/sub 2/O annealing may be conducted in conventional oxidation furnaces in batch order, and is therefore perfectly suitable for mass production.