High-Mobility Ge pMOSFETs With Crystalline ZrO2 Dielectric

High-mobility Ge pMOSFETs with crystalline ZrO2gate dielectric are realized and compared against devices with O3/ZrO2, amorphous ZrO2, and Al2O3/ZrO2gate dielectrics. The crystallization of ZrO2provides for significantly improved effective hole mobility (μeff) and reduced capacitance equivalent thickness (CET), boosting the transistor drive current. An interfacial Al2O3passivation layer enhances μeffbut increases the CET. Passivation-free Ge pMOSFETs with 2.5-nm crystalline ZrO2gate dielectric achieve a higher μeffthan previously reported unstrained Ge pMOSFETs with the CET below 1 nm, at a high inversion-layer charge density.