Beginning at the 45nm node, the semiconductor industry is moving to high-k gate dielectrics and metal gate electrodes for CMOS logic devices [. Although different approaches of building these devices are being pursued, most of the industry has consolidated behind a gate last approach, in which the transistor is built around a dummy poly polysilicon gate, which is subsequently removed and replaced with a metal gate. Current approaches to removing the dummy poly gate include plasma-based dry processes and liquid-phase wet etching.

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