Patent ID: 6762130
Filing Date: 2004-07-13
Classification: H01L

Abstract:
A method of forming a conductive feature in an integrated circuit, comprising:forming a conductive layer near a surface of a substrate; forming an antireflective inorganic layer, which includes a antireflective layer of silicon-rich nitride underlying a layer of silicon oxynitride over the layer of conductive material; forming a photoresist layer over the antireflective inorganic layer; photolithographically patterning the photoresist layer with light of a selected wavelength, to define a photoresist feature having a first CD value; etching the antireflective inorganic layer using the photoresist feature as a mask to remove the antireflective inorganic layer from the surface of the conductive layer at locations away from the photoresist feature, defining an antireflective inorganic layer feature having a CD value corresponding to the first CD value, the antireflective inorganic layer feature underlying the photoresist feature; over-etching the antireflective inorganic layer feature to reduce its CD value to a second CD value smaller than the first CD value, the over-etching also reducing the CD value of the photoresist feature; then etching the conductive layer using the antireflective inorganic layer feature and any remaining portion of the photoresist feature as a mask.