Title :
Successful recovery of moisture-induced TDDB degradation for Cu/ULK(k=2.5) BEOL interconnect
Author :
Sang Hoon Ahn ; Tae-Soo Kim ; Viet Ha Nguyen ; OkHee Park ; KyuHee Han ; Jang-Hee Lee ; JongMyeong Lee ; Gilheyun Choi ; Ho-Kyu Kang ; Chilhee Chung
Author_Institution :
Semicond. R&D Center, Samsung Electron., Hwasung, South Korea
Abstract :
Cu/ULK(k=2.5) dual Damascene back end of line(BEOL) dielectric degradation was studied with respect to post Cu CMP delay prior to dielectric diffusion barrier deposition. The threshold of the delay time was observed beyond which line-to-line leakage current increased rapidly while the dielectric breakdown voltage decreased. This air exposure-dependent degradation was attributed to moisture absorption by damaged ULK during integration, and caused premature TDDB (time-dependent dielectric breakdown) failure. It was found that combination of moisture removal by damage-free UV and mild plasma treatment was able to restore dielectric breakdown voltage as well as TDDB time to failure even well past the threshold of delay time.
Keywords :
chemical mechanical polishing; copper; diffusion barriers; electric breakdown; metallisation; moisture; BEOL interconnect; CMP delay; Cu; Cu-ULK; TDDB failure; damage- free UV; delay time; dielectric breakdown voltage; dielectric degradation; dielectric diffusion barrier deposition; dual damascene; line-to-line leakage current; moisture absorption; moisture-induced TDDB degradation; time-dependent dielectric breakdown failure; Degradation; Delay; Dielectric breakdown; Dielectrics; Leakage current; Moisture; Plasmas;
Conference_Titel :
Interconnect Technology Conference (IITC), 2012 IEEE International
Conference_Location :
San Jose, CA
Print_ISBN :
978-1-4673-1138-0
Electronic_ISBN :
pending
DOI :
10.1109/IITC.2012.6251653
