Patent ID: 6709983
Filing Date: 2004-03-23
Classification: H01L

Abstract:
A semiconductor processing method, comprising:providing a semiconductor substrate having a first material, second material and third material; the second material being over the first material, and the third material being over the second material; the third material having a thickness of at least 250 Ã¥; forming a patterned layer of photoresist over the third material, the patterned layer of photoresist having an opening provided therethrough; removing portions of the second and third materials while the photoresist is thereover to extend the opening through the second and third materials and to proximate a surface of the first material; the extended opening having a depth and a width; removing the photoresist from over the third material; and after removing the photoresist, exposing the substrate to reactive ion etching conditions which comprise subjecting exposed surfaces of the substrate to a gas having components therein which are reactive with the second and third materials, and wherein a total concentration of such components within the gas is less than 4.5%, by volume; the etching conditions removing all of the third material from over the second material while increasing the width of the opening by no more than 100 Ã¥ and while increasing the depth of the opening by no more than 50 Ã¥.