Title :
Effect of FSG fluorine diffusion on via resistance and yield
Author :
Kang, L.H. ; Neo, T.L.
fDate :
30 Sept.-2 Oct. 2003
Abstract :
Low dielectric constant (k) fluorinated silicate glass (FSG) is used for 0.18um backend integration to improve device speed and reduce power dissipation. This film requires a cap layer to prevent fluorine diffusion that can cause problem such as film de-lamination. In this study, fluorine stability in FSG and the effectiveness of the cap layer in preventing fluorine diffusion from FSG were investigated. Fluorine can diffuse through the cap and react with Ti to form a fluorinated film between W plug and AlCu. This leads to high via resistance (Rc) and low yield. The study showed that other than the as-deposited cap thickness, subsequent process stages, such as WCMP over-polish and buffing also play a part in capping effectiveness.
Keywords :
delamination; diffusion; diffusion barriers; electric resistance; fluoride glasses; integrated circuit yield; permittivity; polishing; thin films; 0.18 micron; AlCu alloys; FSG fluorine diffusion; SiO2F; W plug; WCMP over polishing; backend integration; cap thickness; dielectric constant; film delamination; fluorinated silicate glass; fluorine stability; power dissipation; resistance; Chemical vapor deposition; Dielectric constant; Glass manufacturing; Manufacturing systems; Plasma applications; Plasma chemistry; Plasma stability; Plugs; Silicon; Sputter etching;
Conference_Titel :
Semiconductor Manufacturing, 2003 IEEE International Symposium on
Print_ISBN :
0-7803-7894-6
DOI :
10.1109/ISSM.2003.1243264
