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

fYear

2012

fDate

4-6 June 2012

Firstpage

1

Lastpage

3

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;

fLanguage

English

Publisher

ieee

Conference_Titel

Interconnect Technology Conference (IITC), 2012 IEEE International

Conference_Location

San Jose, CA

ISSN

pending

Print_ISBN

978-1-4673-1138-0

Electronic_ISBN

pending

Type

conf

DOI

10.1109/IITC.2012.6251653

Filename

6251653