A method is described for selectively
etching a high k
dielectric layer that is preferably a
hafnium or
zirconium oxide,
silicate,
nitride, or oxynitride with a selectivity of greater than 2:1 relative to
silicon oxide, polysilicon, or
silicon. The
plasma etch
chemistry is comprised of one or more
halogen containing gases such as CF4, CHF3, CH2F2, CH3F, C4F8, C4F6, C5F6, BCl3, Br2, HF, HCl, HBr, HI, and NF3 and leaves no etch residues. An
inert gas or an
inert gas and oxidant gas may be added to the
halogen containing gas. In one embodiment, a high k
gate dielectric layer is removed on portions of an active area in a MOS
transistor. Alternatively, the high k
dielectric layer is used in a
capacitor between two conducting
layers and is selectively removed from portions of an ILD layer.