Patent ID: 7862985

Claim:
A method of double patterning a thin film on a substrate, comprising: preparing a film stack on said substrate, said film stack comprising said thin film formed on said substrate, an organic planarization layer (OPL) formed on said thin film using a spin-on technique so as to be effective for planarizing a surface, a developable anti-reflective coating (ARC) layer formed on said OPL, and a first layer of photo-resist formed on said developable ARC layer, wherein said first layer of photo-resist and said developable ARC layer are the same tone; imaging said first layer of photo-resist and said developable ARC layer with a first image pattern; developing said first layer of photo-resist and said developable ARC layer to form said first image pattern in said first layer of photo-resist and said developable ARC layer; removing said first layer of photo-resist; forming a second layer of photo-resist on said developable ARC layer, wherein said second layer of photo-resist is the same tone as said first layer of photo-resist and said developable ARC layer; imaging said second layer of photo-resist and said developable ARC layer with a second image pattern that is spaced apart from said first image pattern at a distance that is greater than zero and less than or equal to approximately 50 nm; and developing said second layer of photo-resist and said developable ARC layer to form said second image pattern in said second layer of photo-resist and said developable ARC layer.