La2O3/Si0.3Ge0.7 p-MOSFETs with high hole mobility and good device characteristics

Abstract

We have studied the high-k La2O3 p-MOSFETs on Si0.3Ge0.7 substrate. Nearly identical gate oxide current, capacitance density, and time-dependent dielectric breakdown (TDDB) re obtained for La2O3/Si and La2O3/Si0.3Ge0.7 devices that indicate the excellent Si0.3Ge0.7 quality without any side effect. The measured hole mobility in nitrided La2O3/Si p-MOSFETs is 31 cm(2)/V-s and comparable with published data in nitrided HfO2/Si p-MOSFETs. In sharp contrast, a higher mobility of 55 cm(2)/V-s is measured in La2O3/Si0.3Ge0.7 p-MOSFET, which is improved by 1.8 times as compared with La2O3/Si control devices. The high mobility in Si0.3Ge0.7 p-MOSFET gives another step for integrating high-k gate dielectrics into VLSI process.