HIGHLY SELECTIVE OXYGEN FREE SILICON NITRIDE ETCH

摘要

A method for selectively etching silicon nitride with respect to silicon oxide is provided. An oxygen free silicon nitride etch gas comprising H2 and either CF4 or CXHYFZ (X≧1, Y≧1, Z≧1) is provided. An RF power is provided to form the etch gas into a plasma, wherein the silicon nitride is exposed to the plasma.