Advances in la-based high-k dielectrics for MOS applications

This paper reviews the studies on La-based high-k dielectrics formetal-oxide-semiconductor (MOS) applications in recent years. According to the analyses of the physical and chemical characteristics of La₂O₃, its hygroscopicity and defects (oxygen vacancies, oxygen interstitials, interface states, and grain boundary states) are the main problems for high-performance devices. Reports show that post-deposition treatments (high temperature, laser), nitrogen incorporation and doping by other high-k material are capable of solving these problems. On the other hand, doping La into other high-k oxides can effectively passivate their oxygen vacancies and improve the threshold voltages of relevant MOS devices, thus improving the device performance. Investigations onMOS devices including non-volatile memory,MOS field-effect transistor, thin-film transistor, and novel devices (FinFET and nanowire-based transistor) suggest that La-based high-k dielectrics have high potential to fulfill the high-performance requirements in futureMOS applications.