Control of deposition profile of Cu for large-scale integration (LSI) interconnects by plasma chemical vapor deposition*
Kosuke Takenaka, Masaharu Shiratani, Manabu Takeshita, Makoto Kita, Kazunori Koga, and Yukio Watanabe
Department of Electronics, Kyushu University, Fukuoka, Japan
Abstract: H-assisted plasma chemical vapor deposition (HAPCVD) realizes control of deposition profile of Cu in trenches. The key to the control is ion irradiation to surfaces. With increasing the flux and energy of ions, the profile changes from conformal to subconformal and then to an anisotropic one, for which Cu material is filled from the bottom of the trench without deposition on the sidewall. H3+ and ArH+ are identified as the major ionic species which contribute to the control, and hence the deposition profile also depends on a ratio R = H2/(Ar + H2).
Keywords: Cu interconnects; plasma chemical vapor deposition; deposition profile; anisotropy; trench.
*Paper based on a presentation at the 16th International Symposium on Plasma Chemistry (ISPC-16), Taormina, Italy, 22-27 June 2003. Other presentations are published in this issue, pp. 345-495.