Title :
Critical ultra low-k TDDB reliability issues for advanced CMOS technologies
Author :
Chen, F. ; Shinosky, M. ; Li, B. ; Gambino, J. ; Mongeon, S. ; Pokrinchak, P. ; Aitken, J. ; Badami, D. ; Angyal, M. ; Achanta, R. ; Bonilla, G. ; Yang, G. ; Liu, P. ; Li, K. ; Sudijono, J. ; Tan, Y. ; Tang, T.J. ; Child, C.
Author_Institution :
IBM Microelectron., Essex Junction, VT, USA
Abstract :
During technology development, the study of ultra low-k (ULK) TDDB is important for assuring robust reliability. As the technology advances, several critical ULK TDDB issues were faced for the first time and needed to be addressed. First, the increase of ULK leakage current noise level induced by soft breakdown during stress was observed. Second, it was found that ULK had lower field acceleration than dense low-k. Such process and material dependences of ULK TDDB kinetics were investigated, and an optimal process to improve ULK voltage acceleration was identified. Last, as the reliability margin for ULK TDDB of via-related structures is greatly reduced at advanced CMOS technologies, a systematic study of via TDDB regarding area scaling and test structure design was conducted. It was found that only a portion of the total vias possibly determines the low-k via TDDB. A new ldquofatalrdquo via ratio concept is introduced to replace the as-designed area ratio for TDDB area scaling in structures with vias, and a methodology called shift and compare (S&C) is proposed to determine the ldquofatalrdquo via ratio.
Keywords :
CMOS integrated circuits; electric breakdown; integrated circuit design; integrated circuit noise; integrated circuit reliability; low-k dielectric thin films; CMOS technology; ULK TDDB kinetics; critical ultra low-k TDDB reliability; leakage current noise; lower field acceleration; soft breakdown; test structure design; time-dependent dielectric breakdown; Acceleration; CMOS technology; Electric breakdown; Kinetic theory; Leakage current; Noise level; Noise robustness; Stress; System testing; Voltage; Cu interconnect; I-V conduction slope; Poole-Frenkel; Schottky emission; low-k TDDB voltage acceleration; low-k hard breakdown; low-k soft breakdown; low-k via TDDB; reliability; time-dependent dielectric breakdown;
Conference_Titel :
Reliability Physics Symposium, 2009 IEEE International
Conference_Location :
Montreal, QC
Print_ISBN :
978-1-4244-2888-5
Electronic_ISBN :
1541-7026
DOI :
10.1109/IRPS.2009.5173298
