Patent ID: 8124537

Claim:
A method for etching an integrated circuit structure, comprising: (a) providing a base structure comprising a substrate, the base structure having a trench with side surfaces and a bottom surface; (b) providing a layer to be etched over the base structure; (c) providing a first polymer layer over the layer to be etched, the first polymer layer having a first portion over the side surfaces of the trench, a second portion over the bottom surface of the trench, and a third portion over a top surface of the base structure adjacent the trench; (d) providing a capping polymer layer over at least the third portion of the first polymer layer; (e) performing a first etching step to remove the second portion of the first polymer layer to expose a portion of the layer to be etched within the trench; and (f) performing a second etching step to remove a portion of the layer to be etched located within the trench to expose a portion of the base structure; wherein steps (b) through (f) are performed without a photo process, and without having a photoresist mask over the base structure or the trench, the first polymer layer protects a portion of the layer to be etched located directly adjacent to the trench during the second etching step.