Effect of post-metallization annealing on W/Cr-metallized silicon junctions

The 1 μm “WAl” complementary metal-oxide-semiconductor process developed at CNET Grenoble uses a W/Cr bilayer as the first-level metal. In this paper the effects of the final (aluminium) anneal of the structures on the properties of W/Cr-metallized junction devices are discussed. By using several analytical techniques a direct correlation between junction leakage and structure has been established. The main cause of leakage current observed after annealing at above 400°C was found to be the generation of film-edge-induced dislocations associated with chromium disilicide formation.