Electron mobility improvement by in situ annealing before deposition of HfO_2 gate dielectric with equivalent oxide thickness of sub-1.0nm in In_(0.53)Ga_(0.47)As n-type metal-insulator-semiconductor field-effect transistor

摘要

The electron mobility in HfO_2/In_(0.53)Ga_(0.47)As n-type metal-insulator-semiconductor field-effect transistors (nMISFETs) has been found to be significantly enhanced in the sub-1.0nm equivalent oxide thickness (EOT) regime by annealing before the atomic layer deposition (ALD) of the HfO_2 gate dielectric. XPS measurements revealed that the predeposition annealing increased the amount of GaO_x and reduced the amount of AsO_x at the MIS interface, which is considered to reduce the trapped charge density and enhance the mobility, especially in the low-surface-carrier-density region.