METHOD FOR CONTROLLING THE PROFILE OF AN ETCHED METALLIC LAYER

摘要

An ashing chemistry employing a combination of Cl2 and N2 is provided, which removes residual material from sidewalls of a patterned metallic hard mask layer without residue such that the sidewalls of the patterned metallic hard mask layer are vertical. The vertical profiled of the sidewalls of the patterned metallic hard mask layer can be advantageously employed to reduce pattern factor dependency in the etch bias between the pattern transferred into an underlying layer and the pattern as formed on the metallic hard mask layer. Further, the ashing chemistry can be employed to enhance removal of stringers in vertical portions of a metallic material layer.

主权项

1. A method of patterning a structure, said method comprising:
forming a vertical stack, from bottom to top, comprising at least a material layer, a dielectric hard mask layer, a metallic hard mask layer, an organic planarization layer (OPL), and a photoresist layer; lithographically patterning said photoresist layer; transferring a pattern in said photoresist layer through said OPL employing a first anisotropic etch; transferring said pattern through said metallic hard mask layer employing a second anisotropic etch while forming a organo-metallic passivation spacer on sidewalls of an opening in said metallic hard mask layer, said organo-metallic passivation spacer including a compound of at least an elemental metal in said metallic hard mask layer and a halogen atom; transferring said pattern through said dielectric hard mask layer employing a third anisotropic etch; and simultaneously removing a residual portion of said OPL and said organo-metallic passivation spacer employing an ashing process, said ashing process employing a combination of Cl2 and N2 to remove said OPL and said organo-metallic passivation spacer.