Al planarization processes for multilayer metallization of quarter micrometer devices

Autor: Xu, Zheng, Kieu, Hoa, Raaijmakers, Ivo J., Tepman, Avi
Zdroj: Thin Solid Films; December 1994, Vol. 253 Issue: 1-2 p367-371, 5p
Abstrakt: Al planarization technology for application in quarter micrometer devices was explored. High temperature flow process as well as two-step cold/hot sputtering processes were investigated. Quarter micrometer contacts of dept. 1.2 μm were successfully filled by two-step cold/hot sputtering. Multilayer structures were planarized, yielding via resistance (<0.6Ω) lower than those of metallization based on tungsten-plugs. The key factors for reliable filing of contacts are a low base pressure, adequate coverage of the wetting layer (titanium) and continuous coverage of the first nucleation layer in the contacts. A low temperature (450 °C) process was demontrated. Aluminum deposited onto titanium results in a high surface reflectivity (210%, normalized to bare Si at 436 nm). In comparison with the flow process, the two-step cold/hot sputtering proces showed a unique advantage in that it was able to fill high aspect ration contacts at low temperature.
Databáze: Supplemental Index