Dual damascene architectures evaluation for the 0.18 /spl mu/m technology and below

This paper compares three different schemes to pattern dual damascene (DD) structures. The Self Aligned (SA), Via First (VF), and Trench First (TF) architectures are compared in terms of complexity, process latitude, and sensitivity to lithography misalignment using 0.18-/spl mu/m copper/oxide two metal level structures. The integration of thick metal lines is also discussed, for the upper levels of interconnects. This study shows that the VF architecture has the best via chain yield, regardless of the test configuration, and allows to pattern thick metal DD structures with high yield. The VF technique was used to manufacture a six copper level device, with functional yield similar to that obtained with an AlCu/HSQ Back End Of Line (BEOL).