US Patent 7964512 Method for etching high dielectric constant materials

In one implementation, a method is provided for etching a high k dielectric material in a plasma etch reactor, the method comprising plasma etching the high k dielectric material with a first plasma gas reactant mixture having BCl3. The high k dielectric material may include Al2O3 in a stack having a silicon layer. The etching may include supplying a passivation gas, for example C2H4, and may further include supplying a diluent gas such as a noble gas, for example He. In some implementations, the etching may be performed with a reactive ion etch process.