Patent ID: 8329512

Claim:
A method of making a device, comprising: forming a hard mask layer over a sacrificial layer; forming a first photoresist layer over the hard mask layer; patterning the first photoresist layer to form first photoresist features; rendering the first photoresist features insoluble to a solvent; forming a second photoresist layer over the first photoresist features; patterning the second photoresist layer to form second photoresist features; etching the hard mask layer using the first and the second photoresist features as a mask to form hard mask features; forming a spacer layer over the hard mask features; etching the spacer layer to form spacer features and to expose the hard mask features; forming third masking features between the spacer features; removing the spacer features; etching the sacrificial layer using the hard mask features and the third masking features as a mask to form sacrificial features; forming an insulating filler layer between the sacrificial features; and removing the sacrificial features to form openings in the insulating filler layer.