A stress enhanced MOS circuit and methods for its fabrication are
provided. The stress enhanced MOS circuit comprises a semiconductor
substrate and a gate insulator overlying the semiconductor substrate. A
gate electrode overlies the gate insulator; the gate electrode has side
walls and comprising a layer of polycrystalline silicon having a first
thickness in contact with the gate insulator and a layer of electrically
conductive stressed material having a second thickness greater than the
first thickness overlying the layer of polycrystalline silicon. A stress
liner overlies the side walls of the gate electrode.