Development of MIM/Ta2O5 capacitor process for 0.10-µm DRAM

As the fabrication dimension becomes smaller, it becomes increasingly difficult to ensure storage capacitance for DRAM. For this reason, a capacitor process using high-permittivity insulating films is strongly desired. In the research reported here, an MIM/tantalum pentoxide capacitor process is developed with ruthenium as an electrode material. The ruthenium CVD technique, the use of amorphous tantalum nitride as anti-oxide barrier metal, and a contamination elimination process using periodic acid have been developed. By packaging as 0.13-µm DRAM, capacitance performance equivalent to silica film is realized with a film thickness of 0.8 nm. The process is considered to be applicable to 0.10-µm DRAM. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 87(2): 26–36, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10111