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KAREN MAEX, ZS. TOKEI, A. SATTA, F. LANCKMANS, W. WU & F. IACOPI, IMEC, Leuven, Belgium

ABSTRACT
The introduction of new dielectrics in the Back End of Line (BEOL) processes is very challenging. The choice of the low k dielectric has a large impact on all subsequent steps in the process, i.e. on the deposition of hard masks, the patterning and strip process and the post dry etch clean. The mechanical properties of the low k dielectric of choice are directly related to the Cu deposition and the Cu CMP step. What is often overlooked is that the compatibility of the barrier with the low k materials is essential to ensure the diffusion barrier properties for Cu. In this paper an overview will be given of the current and future barrier deposition techniques and their compatibility with current and future low k dielectrics. It is clear that a barrier integrity test vehicle is mandatory to ensure barrier quality on the low k material with relevant feature dimensions for the technology in development.