Title :
Low-pressure CMP for reliable porous low-k/Cu integration
Author :
Kondo, S. ; Tokitoh, S. ; Yoon, B.U. ; Namiki, A. ; Sone, A. ; Ohashi, N. ; Misawa, K. ; Sone, S. ; Shin, H.J. ; Yoshie, T. ; Yoneda, K. ; Shimada, M. ; Ogawa, S. ; Matsumoto, I. ; Kobayashi, N.
Author_Institution :
Semicond. Leading Edge Technol. Inc., Tsukuba, Japan
Abstract :
We developed a method of low-pressure CMP for the Cu damascene process on 300-mm wafers in order to prevent porous low-k film from being damaged. A new failure criterion, the time to CMP-induced delamination, was defined and found to be strongly dependent on the Young´s modulus of the low-k film. In order to integrate porous low-k films into Cu damascene interconnects (k<2.5), a modulus of more than 8 GPa is required to suppress CMP-induced damage. He-plasma treatment before cap-CVD film deposition was also effective to improve low-k film adhesion. Because the time to delamination is inversely proportional to the polishing pressure, a high-removal-rate process is important even in low-pressure CMP. With a goal of integrating low-k materials (k<2.0) we investigated the feasibility of ultra-low pressure CMP (at 0.8 psi).
Keywords :
CVD coatings; Young´s modulus; adhesion; chemical mechanical polishing; copper; delamination; dielectric materials; dielectric thin films; integrated circuit interconnections; interconnections; metallic thin films; plasma materials processing; porous materials; 300 mm; CVD film deposition; Cu; Cu damascene interconnects; He-plasma treatment; Young´s modulus; delamination; film adhesion; low-pressure CMP; wafers; Adhesives; Copper; Delamination; Dielectric materials; Friction; Lead compounds; Parasitic capacitance; Pressure control; Slurries; Stress;
Conference_Titel :
Interconnect Technology Conference, 2003. Proceedings of the IEEE 2003 International
Print_ISBN :
0-7803-7797-4
DOI :
10.1109/IITC.2003.1219720
