Patent ID: 6306767
Filing Date: 2001-10-23
Classification: H01L

Abstract:
A method for forming a patterned layer comprising:providing a topographic substrate;forming conformally over the topographic substrate a blanket target layer formed of a target material, the blanket target layer having a lower substantially horizontal portion, an upper substantially horizontal portion and an intermediate portion therebetween;forming upon the lower substantially horizontal portion of the blanket target layer a first masking layer formed of a first masking material and forming upon the upper substantially horizontal portion of the blanket target layer a second masking layer formed of a second masking material;etching, while employing an etch method having an enhanced sequential selectivity for the first masking material and the target material with respect to the second masking material, the first masking layer and the lower substantially horizontal portion of the blanket target layer to form a patterned target layer which leaves exposed a portion of the substrate beneath the lower horizontal portion of the blanket target layer while leaving unetched the upper substantially horizontal portion of the blanket target layer.