A plasma composition for the selective etching of high-k materials

摘要

The present invention relates to a method for the selective removal of a high-k layer such as HfO 2 over silicon or silicon dioxide. More specifically a method for etching high-k selectively over silicon and silicon dioxide and a plasma composition for performing said selective etch process is disclosed. Using a BCl 3 plasma with well defined concentrations of nitrogen makes it possible to etch high-k with at a reasonable etch rate while silicon and silicon dioxide have an etch rate of almost zero.