Title :
Effect of stress control layer (SCL) on via-stability in organic low-k/Cu dual damascene interconnects under thermal cycle stress
Author :
Tagami, M. ; Ohtake, H. ; Hayashi, Y. ; Miyamoto, H.
Author_Institution :
Silicon Syst. Res. Lab., NEC Corp., Kanagawa, Japan
Abstract :
Stability of organic low-k/Cu dual damascene interconnect under thermal cycle stresses is investigated, concluding that the thermal stability is improved by introducing Stress Control Layer (SCL) between metal-level inter-layer dielectric (ILD) film and via-level ILD film. The mismatches of the coefficient of thermal expansion (CTE) and the Young´s modulus among the Cu, ILD and SCL films cause the stress voiding defects around the via-holes. In the case of CTE of SCL close to that of Cu, the via-stress opening is suppressed. When the modulus of SCL is closed to that of ILD, the voiding in the ILD around the via is suppressed. The selection of SCL material is a key part to improve the reliability of organic Low-k/Cu interconnect under severe thermal cycles.
Keywords :
Young´s modulus; copper; dielectric thin films; integrated circuit interconnections; integrated circuit reliability; organic compounds; thermal expansion; thermal stability; thermal stresses; voids (solid); Cu; Young´s modulus; metal-level inter-layer dielectric film; organic low-k/Cu dual damascene interconnects; reliability; stress control layer effects; stress voiding defects; thermal cycle stress; thermal expansion coefficient mismatch; thermal stability; via-level interlayer dielectric film; via-stress opening; Dielectric films; Dielectric materials; National electric code; Organic materials; Stress control; Tensile stress; Testing; Thermal resistance; Thermal stability; Thermal stresses;
Conference_Titel :
Interconnect Technology Conference, 2003. Proceedings of the IEEE 2003 International
Print_ISBN :
0-7803-7797-4
DOI :
10.1109/IITC.2003.1219757
