High mobility SiGe p-channel metal-oxide-semiconductor field-effect transistors epitaxially grown on Si(100) substrates with HfSiO₂ high-k dielectric and metal gate

High mobility metal-oxide-semiconductor field-effect transistors (MOSFETs) are demonstrated on strained or relaxed SiGe-on-Si heterostructures with Si cap/SiGe channel quantum well structures. Si cap processing is frequently used to enhance hole mobility of SiGe pMOSFETs by improving the interface quality of high-k gate dielectrics and SiGe channels. However, one of mechanisms that limits future gate oxide scaling is Ge enhanced Si oxidation, which results in a thick Si oxide interface layer. In this work, without using Si cap process, we have fabricated high mobility SiGe channel pMOSFETs after optimizing epitaxial SiGe-on-Si and high-k dielectric/metal gate process. High mobility with low off-state current have been achieved and correlated with epitaxial SiGe-on-Si processes.