Patent ID: 8877641
Filing Date: 2014-11-04
Classification: H01L

Abstract:
1. A method for fabricating a semiconductor device, the method comprising: providing a semiconductor substrate with a plurality of mask layers formed on the semiconductor substrate, wherein the plurality of mask layers comprise: an organic antireflective coating/silicon oxynitride (oARC/SiON) film stack for mitigating line-edge roughness in the semiconductor device; providing a patterned photoresist layer over the plurality of mask layers formed over the substrate, wherein the patterned photoresist layer is in contact with the oARC/SiON film stack; and etching the plurality of mask layers formed on the substrate, using the patterned photoresist layer as an etching mask to form at least one trench in the plurality of mask layers, wherein the oARC/SiON film stack is etched with an overetch that is less than 30 percent, wherein the overetch of less than 30 percent prevents resulting increase in top and bottom line width roughness while cleaning out the SiON, and wherein a higher percentage of SiON overetch provides undesirable increase in to and bottom average line width roughness.