Sequential sputter deposition of titanium nitride and aluminum

A sequential deposition process (without air exposure or postdeposition anneal) in a multichamber UHV magnetron sputter deposition system is described. The TiN film has low resistivity (40 mu Omega -cm), low stress (0.23*10/sup 9/ dyne/cm/sup 2/), and excellent diffusion barrier properties; it is stable after a 600 degrees C, 30-min anneal. For nonoptimum films, a RF bias is shown to enhance the TiN barrier property. Oxygen addition during deposition increases film resistivity. Air exposure forms a titanium oxide layer in the Al-TiN interface, reducing the diffusion of titanium from TiN into aluminum.<
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