Title :
Void formation in a TiW/AlSiCu metallisation scheme
Author :
van Houtum, H.J.W. ; Tibbe, J. ; Dirks, A.G.
Author_Institution :
Philips Semicond., Nijmegen, Netherlands
Abstract :
The voiding behaviour of AlSiCu is described in an TiW/AlSiCu metallization scheme for submicron technology. A direct correlation was found between waiting time between TiW and AlSiCu deposition and voiding. Direct transfer of wafers between the two metal deposition systems enhances voiding. Analysis of the TiW/AlSiCu bilayer with several interface conditions revealed a rather clear correlation to voiding: Interaction between AlSiCu and TiW. It is proposed that the TiW-Al(SiCu) interaction enhances voiding in the AlSiCu interconnection due to formation of intermetallic phases at the Al grain boundaries. Volume effects of intermetallic phase formation enhances local strain at the Al grain boundaries and may initiate void formation
Keywords :
VLSI; aluminium alloys; copper alloys; metallisation; reliability; silicon alloys; titanium alloys; tungsten alloys; Al grain boundaries; AlSiCu alloy metallisation; TiW alloy films; TiW-AlSiCu; VLSI; exposure to air; formation of intermetallic phases; interface conditions; local strain; multilevel interconnection; reliability issues; voiding behaviour; waiting time; Electrons; Grain boundaries; Intermetallic; Metallization; Passivation; Plasma measurements; Sputter etching; Sputtering; Surface cleaning; Thermal stresses;
Conference_Titel :
VLSI Multilevel Interconnection Conference, 1991, Proceedings., Eighth International IEEE
Conference_Location :
Santa Clara, CA
Print_ISBN :
0-87942-673-X
DOI :
10.1109/VMIC.1991.152993
