Patent ID: 6764911
Filing Date: 2004-07-20
Classification: H01L

Abstract:
A method for fabricating a spacer layer comprising:providing a substrate having formed thereover a topographic feature; forming over the substrate including the topographic feature a first layer of a first material having formed thereupon a second layer of a second material; etching, while employing a first etch method having a first enhanced etch selectivity for the second material with respect to the first material, the second layer to form therefrom a second spacer layer formed upon the first layer; etching, while employing a second etch method having a second substantially neutral etch selectivity for the second material with respect to the first material, the second spacer layer and first layer to form therefrom an etched second spacer layer formed upon a partially etched first layer; and etching, while employing a third etch method having a third enhanced etch selectivity for the first material with respect to the second material, the partially etched first layer to form a first spacer layer having formed thereupon the etched second spacer layer wherein outer side surface of said first spacer and said second spacer are aligned.