High Mobility High-Ge-Content SiGe PMOSFETs Using Al 2 O 3 /HfO 2 Stacks With In-Situ O 3 Treatment

We developed an Al2O3/HfO2bi-layer gate dielectric with an in-situ O3treatment for interface state density (Dit) and gate leakage current density (Jg) reductions on SiGe channels. We observed Ge-content dependent equivalent oxide thickness (EOT) scaling and EOT 0.44 nm was achieved with an MOS capacitor with a Si0.05Ge0.95substrate. The O3treatment enabled application to non-planar device structures and we demonstrated five orders of magnitude lower off currents (Ioff), a sub-threshold slope of 68 mV/decade, and a very high hole mobility of 457 cm2V-1s-1at an inversion carrier density (Ninv) of 1×1013cm-2for asymmetrically strained SiGe PMOSFETs with Ge% of 65%-70%.