Title :
Low damage via formation with low resistance by NH3 thermal reduction for Cu/ultra low-k interconnects
Author :
Okamura, Hiroshi ; Ogawa, Shimchi
Author_Institution :
Dept. of Res., Semicond. Leading Edge Technol. Inc., Ibaraki, Japan
Abstract :
In order to minimize plasma-damage on porous low-k films, a pre-clean treatment, NH3 thermal reduction, to remove CuOx thin layer from a via bottom before barrier metal deposition was investigated. A reduction rate of 3 nm/min for CuOx layer was obtained at 360 C degrees, and via resistance was reduced to 75% without any damage into porous low-k films such as increase of dielectric constant (k) and decrease in low-k film thickness, while conventional Ar or He/H2 plasma pre-clean treatments in severe damages into low-k-films.
Keywords :
copper; copper compounds; diffusion barriers; integrated circuit interconnections; surface cleaning; 360 C; Cu interconnects; CuO; CuOx thin layer; NH3 thermal reduction; barrier metal deposition; dielectric constant; low damage via formation; low-k film thickness; plasma pre-clean treatments; plasma-damage minimization; porous low-k films; pre-clean treatment; ultra low-k interconnects; via bottom; via resistance; Argon; Plasma applications; Plasma measurements; Plasma properties; Plasma temperature; Pollution measurement; Temperature dependence; Thermal resistance; Thickness measurement; Wiring;
Conference_Titel :
Interconnect Technology Conference, 2004. Proceedings of the IEEE 2004 International
Print_ISBN :
0-7803-8308-7
DOI :
10.1109/IITC.2004.1345678
