| abstract |
A method for etching metal silicide layers 22a, 22b and polysilicon layers 24a, 24b on a substrate 20 with high etching selectivity, and anisotropic etching properties, is described. In the method, the substrate 20 is placed in a plasma zone 55, and process gas comprising chlorine, oxygen and optionally helium gas, is introduced into the plasma zone. A plasma is formed from the process gas to etch the metal silicide layer 22 at high etching selectivity relative to etching of the polysilicon layer 24, while providing substantially anisotropic etching of the metal silicide and polysilicon layers. Preferably, the plasma is formed using combined inductive and capacitive plasma sources. |