Patent ID: 7906275

Claim:
A method for self-aligned spatial frequency doubling in one dimension comprising: forming a film stack over a substrate such that the film stack comprises a first pattern having a first pitch p formed by an optical exposure, the first pitch p being at least smaller than twice the bandpass limit for the optical exposure, wherein the formation of the first pattern comprises: forming a top resist layer overhanging a lower resist layer, the lower resist layer having a thickness of h and a width of about p/4 and the top resist layer having a thickness of less than h and a width of about 3p/4; and forming a second pattern using the first pattern by one or more nonlinear processing steps to provide the second pattern with a second pitch p 2 =p/2; wherein the formation of the second pattern comprises: depositing one or more of a metal layer and a dielectric layer over the substrate under the overhanging top resist layer by shadow evaporating at least one of the metal layer or the dielectric layer at an angle θ=tan −1 (p/4h) such that the one or more of the metal layer and the dielectric layer from the second pattern.