High mobility Si/SiGe strained channel MOS transistors with HfO/sub 2//TiN gate stack

We integrate a strained Si channel with HfO/sub 2/ dielectric and TiN metal gate electrode to demonstrate NMOS transistors with electron mobility better than the universal mobility curve for SiO/sub 2/, inversion equivalent oxide thickness of 1.4 nm (EOT=1 nm), and with three orders of magnitude reduction in gate leakage. To understand the physical mechanism that improves the inversion electron mobility at the HfO/sub 2//strained Si interface, we measure mobility at various temperatures and extract the various scattering components.