Patent ID: 8476160

Claim:
A method of forming a structure comprising: forming a stack including at least a metallic layer and a first low dielectric constant (low-k) dielectric material layer containing carbon on a substrate; exposing a sidewall of said first low-k dielectric material layer by forming a recessed region therein; forming a damaged sidewall portion by de-carbonizing a portion of said first low-k dielectric material layer located at said sidewall; filling said recessed region with a second low-k dielectric material layer and planarizing said second low-k dielectric material layer, wherein a top surface of said damaged sidewall portion is exposed; removing said damaged sidewall portion selective to an undamaged portion of said first low-k dielectric material layer and said second low-k dielectric material layer, wherein a line cavity is formed between said undamaged portion of said first low-k dielectric material layer and said second low-k dielectric material layer; and transferring a pattern of at least a portion of said line cavity into said metallic layer, wherein a trench of a constant width is formed within said metallic layer to form a patterned metallic layer.