MANUFACTURE OF CAPACITOR OF MEMORY DEVICE

摘要

PROBLEM TO BE SOLVED: To restrain a Ta2O5 capacitor effective oxide film from varying in thickness even after a thermal treatment is carried out and improve an electrode material in step coverage, by a method wherein a CVD TiN film, an MOCVD TiN film, and a polysilicon film are successively laminated for the formation of an electrode on a Ta2O5 dielectric thin film. SOLUTION: A polysilicon film 301 is vacuum deposited as a lower electrode of a Ta2O5 capacitor, and then the surface of the film 301 is subjected to an RTN treatment. Then, a Ta2O5 film 302 is deposited as a dielectric thin film through an LPCVD method. The Ta2O5 film 302 is subjected to N2O plasma annealing at 300 to 500 deg.C to remove impurities from it, and then the Ta2O5 film 302 is crystallized. Then, a CVD TiN film 303 and an MOCVD TiN film 304 are evaporated. A doped polysilicon film is deposited on the MOCVD TiN film 304 and then thermally treated. By this setup, the effective oxide film of a Ta2O5 capacitor is restrained from varying in thickness, and an electrode material can be improved in step coverage.