The effect of interfacial layer of high-K dielectrics on GaAs substrate

Abstract

We have studied the interfacial layer formation for atomic layer deposited Al2O3, HfO2, and HfAlO and physical vapor deposited HfO2 and Gd2O3/HfO2 gate stack on GaAs substrates by electrical and physical analysis. It is found that the HfAlO gate dielectric on p-GaAs exhibits excellent electrical properties compared with Al2O3 and HfO2. The HfAlO gate dielectric has low frequency dispersion (∼2%), which are attributed to the reduction of interfacial oxides (GaAsO) at the interface. On the other hand, the presence of thin layer of Gd2O3 between HfO2 and GaAs is an effective way to improve the interface quality such as low frequency dispersion, hysteresis voltage and leakage current © The Electrochemical Society.