Patent ID: 8916054

Claim:
A method of forming a patterned structure comprising: forming a stack comprising, from bottom to top, a substrate, a hard mask layer that is not carbon-based, a soft mask layer including a carbon-based material, and a photoresist; lithographically patterning said photoresist; and transferring a pattern in said photoresist into said soft mask layer employing an anisotropic etch, wherein a carbon-rich polymer including carbon and fluorine is formed on sidewalls around an opening of said soft mask layer, wherein an atomic ratio of carbon to fluorine is greater than 1 within said carbon-rich polymer, wherein said anisotropic etch employs a fluorohydrocarbon-containing plasma, and said carbon-rich polymer is generated by interaction of said fluorohydrocarbon-containing plasma with said soft mask layer, and wherein said fluorohydrocarbon-containing includes ions of C x H y F z , wherein x is an integer selected from 3, 4, 5, and 6, y and z are positive integers, and y is greater than z.