Strained Silicon-Germanium-on-Insulator N-MOSFETs Featuring Lattice Mismatched Source/Drain Stressor and High-Stress Silicon Nitride Liner

A novel strained-SiGe n-channel field-effect transistor (nFET) featuring silicon-carbon (Si0.99C0.01) source/drain (S/D) stressors and tensile stress nitride (SiN) liner is demonstrated for the first time. The silicon-carbon Si1-yCy material is pseudomorphically grown by selective epitaxy and the carbon mole fraction y incorporated is 1%. Si0.99C0.01 S/D was employed to induce uniaxial tensile strain in the SiGe channel, leading to enhancement in electron mobility. Devices with gate length LG down to 50 nm were fabricated. Up to 55% higher saturation drive current Id,sat was achieved in the strained-SGOI nFETs over control devices. In addition, the incorporation of a tensile stress SiN liner improves Id,sat by an additional 15%.