A method and apparatus are described for fabricating metal gate electrodes (85, 86) over a high-k gate dielectric layer (32) having a rare earth oxide capping layer (44) in at least the NMOS device area by treating the surface of a rare earth oxide capping layer (44) with an oxygen-free plasma process (42) to improve photoresist adhesion, forming a patterned photoresist layer (52) directly on the rare earth oxide capping layer (44), and then applying a wet etch process (62) to remove the exposed portion of the rare earth oxide capping layer (44) from the PMOS device area.