Title :
Enhancing Yield and Reliability by Applying Dry Organic Acid Vapor Cleaning to Copper Contact Via-Bottom for 32-nm Nodes and Beyond
Author :
Kudo, H. ; Ishikawa, K. ; Nakaishi, M. ; Tsukune, A. ; Ozaki, S. ; Nakata, Y. ; Akiyama, S. ; Mizushima, Y. ; Hayashi, M. ; Akbar, Ade A. ; Kouno, T. ; Iwata, H. ; Iba, Y. ; Ohba, T. ; Futatsugi, T. ; Nakamura, T. ; Sugii, T.
Author_Institution :
Fujitsu Laboratories Limited, Phone: +81-42-532-1249, FAX: +81-42-532-2513, E-mail: kudo.hiroshi@jp.fujitsu.com
Abstract :
Via cleaning using gas-phase organic acid has a high potential for improving the reduction capability of copper oxides (CuO), not degrading porous ultra-low-k dielectrics, and reducing processing cost. We applied our via cleaning technique to intermediate and semi-global levels consisting of homogeneous interlayer dielectric architectures based on the 45-nm technology node. The CuO reduction rate was by a factor of 10, which was much higher compared with that using hydrogen. This allowed us to achieve a 100% yield for a mega-scaled via chain. Via chains treated with gas-phase organic acid also showed greater resistance against stress-induced voiding. In addition, we substantially reduced the via cleaning process cost by a factor of 10 compared with the cost of conventional wet chemical cleaning. In addition, organic acid is preferable because it occurs naturally and is thus ecologically friendly.
Keywords :
Chemicals; Cleaning; Contacts; Copper; Costs; Dielectrics; Etching; Hydrogen; Plasma applications; Wiring;
Conference_Titel :
Interconnect Technology Conference, 2008. IITC 2008. International
Conference_Location :
Burlingame, CA, USA
Print_ISBN :
978-1-4244-1911-1
Electronic_ISBN :
978-1-4244-1912-8
DOI :
10.1109/IITC.2008.4546935
