SULFUR AND FLUORINE CONTAINING ETCH CHEMISTRY FOR IMPROVEMENT OF DISTORTION AND BOW CONTROL FOR HAR ETCH

摘要

In accordance with this disclosure, there is provided several inventions, including a method for etching a plurality of features in a stack comprising alternating layers above a substrate, comprising: providing a steady state flow of an etching gas, wherein the etching gas comprises: a molecule A comprising sulfur and fluorine; a molecule B comprising carbon, fluorine, and hydrogen; and a molecule C comprising carbon and fluorine and not hydrogen; forming the etching gas into a plasma; and etching the features into the stack through the plurality of alternating layers.

主权项

1. A method for etching a plurality of features in a stack comprising at least one layer above a substrate, comprising:
providing a steady state flow of an etching gas, wherein the etching gas comprises:
a molecule A comprising sulfur and fluorine;a molecule B comprising carbon, fluorine, and hydrogen; anda molecule C comprising carbon, fluorine, and not hydrogen; forming the etching gas into a plasma; and etching the features with an aspect ratio of greater than about 30:1 into the stack through the at least one layer, wherein the at least one layer comprises a plurality of alternating layers and wherein the number of features is at least 5, wherein the cross-section of the bottom of each feature has an ellipticity defined as the minimum diameter divided by the maximum diameter, the two diameters taken along perpendicular axes, and wherein the average ellipticity for the features is at least about 0.8.