Electron mobility improvement by in situ annealing before deposition of HfO2gate dielectric with equivalent oxide thickness of sub-1.0 nm in In0.53Ga0.47As n-type metal–insulator–semiconductor field-effect transistor (Electron mobility improvement by in situ annealing before deposition of HfO2 gate dielectric with equivalent oxide thickness of sub-1.0 nm in In0.53Ga0.47As n-type metal–insulator–semiconductor field-effect transistor)