Patent ID: 6919259
Filing Date: 2005-07-19
Classification: H01L

Abstract:
1. A method for dry etching a feature to control an etching depth using endpoint detection and a sacrificial hardmask comprising the steps of: providing a substrate for etching a feature opening into said substrate, said substrate provided with at least a first dielectric layer overlying the substrate; providing at least a second and uppermost dielectric layers comprising a sacrificial hardmask having a predetermined thickness over the at least a first dielectric layer; photolithographically patterning and etching in a first dry etching process through a thickness of the at least a second and uppermost dielectric layers and the at least a first dielectric layer to expose the substrate for dry etching a feature opening; and, dry etching in a second dry etching process the substrate and the sacrificial hardmask layer while simultaneously etching the substrate to endpoint detection of the second dielectric layer to thereby etch through a predetermined thickness of the substrate comprising the feature opening.