Title :
A comparative study of ULK conduction mechanisms and TDDB characteristics for Cu interconnects with and without CoWP metal cap at 32nm technology
Author :
Chen, F. ; Huang, E. ; Shinosky, M. ; Angyal, M. ; Kane, T. ; Wang, Y. ; Kolics, A.
Author_Institution :
IBM Microelectron., Essex Junction, VT, USA
Abstract :
As the current-carrying capability of a copper line is reduced due to interconnect dimension shrinkage, self-aligned CoWP metal-cap has been reported to be helpful to improve degraded electromigration (EM) reliability. However, adoption of this new metal cap in general further exacerbates the already problematic low-k dielectric TDDB reliability at 32nm and beyond. This paper provides a comparative study of ULK conduction mechanisms over a wide range of temperature (30°C to 295°C) and TDDB acceleration kinetics at 125°C for Cu interconnects with and without CoWP metal cap at 32nm technology. It was found that adding CoWP didn´t change the fundamental ULK leakage conduction mechanism and TDDB kinetics if its process was optimized. Comparable leakage and TDDB performance were achieved with an optimized CoWP process.
Keywords :
cobalt compounds; copper; electromigration; reliability; CoWP; CoWP metal cap; Cu; Cu interconnects; TDDB characteristics; ULK conduction mechanisms; ULK leakage conduction mechanism; copper line; electromigration reliability; interconnect dimension shrinkage; low-k dielectric TDDB reliability; size 32 nm; Copper; Degradation; Dielectrics; Kinetic theory; Leakage current; Microelectronics; Stress; Temperature distribution; Testing; Voltage;
Conference_Titel :
Interconnect Technology Conference (IITC), 2010 International
Conference_Location :
Burlingame, CA
Print_ISBN :
978-1-4244-7676-3
DOI :
10.1109/IITC.2010.5510693
