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An experimental study of mobility and velocity enhancement effects is reported for highly strained short-channel p-channel field-effect transistors (pFETs) using a damascene-gate process on Si (100) and (110) substrates. The relationship between the mobility and the saturation velocity of hole under a compressive stress over -2.0 GPa is discussed. The local channel stress of -2.4 GPa is successfully measured with ultraviolet- Raman spectroscopy for the 30-nm-gate-length device with top-cut compressive-stress SiN liner and embedded SiGe. Mobility and saturation-velocity enhancements of (100) substrate are larger than those of (110) under the high channel stress. In consequence, the saturation current on (100) is larger than that on (110) for the pFETs with higher channel stress and shorter gate length. Moreover, the large enhancement rate of saturation velocity to mobility by the uniaxial stress suggests high injection velocity for the pFETs with the stressors since the high channel stress is induced near the potential peak of the source by using the damascene-gate technology. [ABSTRACT FROM AUTHOR]

Newly proposed mobility-booster technologies are demonstrated for metal/high-k gate-stack n- and pMOSFETs. The process combination of top-cut SIN dual stress liners and damascene gates remarkably enhances local channel stress particularly for shorter gate lengths in comparison with a conventional gate-first process. Dummy gate removal in the damascene gate process induces high channel stress, because of the elimination of reaction force from the dummy gate. PFETs with top-cut compressive stress liners and embedded SiGe source/drains are performed by using atomic layer deposition TiNIHfO2 gate stacks with Tinv = 1.4 nm on (100) substrates. On the other hand, nFETs with top-cut tensile stress liners are obtained by using HfSi∞ /HfO2 gate stacks with Tinv = 1.4 nm. High-performance n- and pFETs are achieved with Ton = 1300 and 1000 μA/μm at Ioff = 100 nA/μm, Vdd = 1.0 V, and a gate length of 40 nm, respectively. [ABSTRACT FROM AUTHOR]