Reliability Improvement by Adopting Ti-barrier Metal B for Porous Low-k IL Structure

Author

Sakata, A. ; Yamashita, Shinji ; Omoto, S. ; Hatano, M. ; Wada, Junichi ; Higashi, K. ; Uchi, H. Yama ; Yosho, T. ; Imamizu, K. ; Yamada, M. ; Hasunuma, M. ; Takahashi, S. ; Yamada, A. ; Hasegawa, T. ; Kaneko, H.

Author_Institution

Semicond. Co., Toshiba Corp.

fYear

2006

fDate

5-7 June 2006

Firstpage

101

Lastpage

104

Abstract

This paper elucidated for the first time that titanium (Ti) is an excellent barrier metal (BM) material from the stand point of cost and performance, especially for the porous low-k ILD materials. Both stress induced voiding (SIV) suppression and one order longer electromigration (EM) lifetime were obtained by introducing Ti instead of the conventional tantalum (Ta). It has been considered that the smaller volume change when oxidized and the existence of metallic Ti-O solid-solution phase for Ti would be the reason for its control of moisture penetration from the low-k ILD materials which resulted in excellent SIV suppression. No electrical resistance increase due to intermetallic reaction between Cu and Ti was observed. Furthermore, the suppression of Cu grain boundary migration was attributed to the segregation of Ti atoms at the Cu grain boundaries. This resulted in higher interconnect reliability

Keywords

copper; dielectric materials; electromigration; grain boundary diffusion; integrated circuit interconnections; porous materials; reliability; solid solutions; tantalum; titanium; BM material; Cu; EM lifetime; SIV suppression; Ti-O; barrier metal material; copper grain boundary migration; electromigration lifetime; interconnect reliability; moisture penetration; porous low-k ILD materials; porous low-k ILD structure; reliability improvement; solid-solution phase; stress induced voiding suppression; titanium barrier metal; Costs; Electric resistance; Electromigration; Grain boundaries; Inorganic materials; Intermetallic; Moisture control; Phase change materials; Stress; Titanium;

fLanguage

English

Publisher

ieee

Conference_Titel

Interconnect Technology Conference, 2006 International

Conference_Location

Burlingame, CA

Print_ISBN

1-4244-0104-6

Type

conf

DOI

10.1109/IITC.2006.1648658

Filename

1648658