Title :
Advanced Direct-CMP process for porous low-k thin film
Author :
Korogi, Hayato ; Chibahara, Hiroyuki ; Suzuki, Shigeru ; Tsutsue, Makoto ; Seo, Kohei ; Oka, Yoshihiro ; Goto, Kinya ; Akazawa, Moriaki ; Miyatake, Hiroshi ; Matsumoto, Susumu ; Ueda, Tetsuya
Author_Institution :
Renesas Technol. Corp., Itami
Abstract :
In order to reduce the effective dielectric constant (keff) for the 32 nm technology node and beyond, direct-CMP of a porous low-k film without a protective cap layer is required. However, the degradation of breakdown electric field (Ebd) has been one of critical issues. This study clarified that the Ebd degradation was caused by the pit defects on the surface of porous low-k film during direct-CMP. In order to suppress the pit defects, we evaluated dependency of micro-pores density of CMP pads. As a result, we demonstrated that CMP pads with low-density micro-pores drastically reduced them and improved the Ebd degradation. In this paper, the mechanism for their reduction is also discussed.
Keywords :
chemical mechanical polishing; low-k dielectric thin films; permittivity; breakdown electric field degradation; dielectric constant; direct-CMP process; micropores density; porous low-k thin film; protective cap layer; Chemistry; Cities and towns; Cleaning; Degradation; Dielectric constant; Mercury (metals); Probes; Slurries; Transistors; Water;
Conference_Titel :
Interconnect Technology Conference, 2009. IITC 2009. IEEE International
Conference_Location :
Sapporo, Hokkaido
Print_ISBN :
978-1-4244-4492-2
Electronic_ISBN :
978-1-4244-4493-9
DOI :
10.1109/IITC.2009.5090399