The defect reduction of Cu interconnects by optimized Cu seed layer

Abstract

In Cu interconnects, the disadvantage of physical vapor deposited (PVD) Cu seed is the formation of over-hang on patterned trench. Ar plasma treatment (PT) is utilized to diminish undesirable over-hang profile after the deposition of Cu seed. Moreover, Ar PT improves the surface roughness of Cu seed and enhances the (111) texture of the subsequent electroplated Cu film. By applying Ar PT method, the defects of Cu interconnects have 73% reduction in improvement.