Demonstration of L-g similar to 55 nm pMOSFETs with Si/Si0.25Ge0.75/Si channels, high I-on/I-off (> 5 x 10(4)), and controlled short channel effects (SCEs)

Abstract

High-performance sub-60 nm Si/SiGe (Ge: similar to 75%)/Si heterostructure quantum well pMOSFETs with a conventional MOSFET process flow, including gate-first high-kappa/metal gate stacks with similar to 1 nm equivalent oxide thickness, are demonstrated. For the first time, short gate length (L-g) devices demonstrate not only controlled short channel effects, but also an excellent on-off current (I-on/I-off) ratio (similar to 5 x 10(4) at 55-nm L-g). The intrinsic gate delay of these heterostructures is similar to 3 ps at I-on/I-off similar to 10(4). OFF-state leakage was minimized by controlling the defects in the epitaxial films. Finally, these short Lg devices, when benchmarked against state-of-the-art Si channel pMOSFETs, appear to be very promising in replacing the Si channel in CMOS scaling.