Interactions of WF(6) With TiN/Ti Barriers During W Chemical Vapor Deposition
F buildup in the Ti underlayer of TiN/Ti bilayers is suggested to be the major cause of delamination. High F concentration causes phase formation and alters the chemistry of the Ti/SiO$\sb2$ interface. Large stresses generated due to TiF$\sb3$ formation, and destruction of the Ti glue layer due to TiF$\sb4$ evolution jeopardize the adhesion of the TiN/Ti bilayer at the Ti/SiO$\sb2$ interface. The delamination problem can be alleviated by improving the TiN microstructure and/or by hastening the W nucleation process to minimize the interaction of WF$\sb6$ with the Ti underlayer.
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign