REPLACEMENT METAL GATE STRUCTURES FOR EFFECTIVE WORK FUNCTION CONTROL

摘要

A stack of a barrier metal layer and a first-type work function metal layer is deposited in replacement metal gate schemes. The barrier metal layer can be deposited directly on the gate dielectric layer. The first-type work function metal layer is patterned to be present only in regions of a first type field effect transistor. A second-type work function metal layer is deposited directly on the barrier metal layer in the regions of a second type field effect transistor. Alternately, the first-type work function layer can be deposited directly on the gate dielectric layer. The barrier metal layer is patterned to be present only in regions of a first type field effect transistor. A second-type work function metal layer is deposited directly on the gate dielectric layer in the regions of the second type field effect transistor. A conductive material fill and planarization form dual work function replacement gate structures.