Consistent alignment mark profiles on semiconductor wafers using metal organic chemical vapor deposition titanium nitride protective layer

摘要

Provided is a method and composition for protecting alignment mark trench walls from attack by CMP slurry accumulating in an alignment mark trench during CMP processing. In a preferred embodiment, a metal organic chemical vapor deposition titanium nitride (MOCVDTiN) layer is deposited over a conventionally applied bulk tungsten layer prior to commencing CMP operations. This MOCVDTiN layer is resistant to CMP slurry attack. As a result, the tungsten trench profile remains a consistent and reliable alignment mark.