High temperature thermal stability of the HfO_2/Ge (100) interface as a function of surface preparation studied by synchrotron radiation core level photoemission

摘要

High resolution soft x-ray photoemission spectroscopy (SXPS) have been used to study the high temperature thermal stability of ultra-thin atomic layer deposited (ALD) HfO_2 layers (～1 nm) on sulphur passivated and hydrofluoric acid (HF) treated germanium surfaces. The interfacial oxides which are detected for both surface preparations following HfO_2 deposition can be effectively removed by annealing upto 700 ℃ without any evidence of chemical interaction at the HfO_2/Ge interface. The estimated valence and conduction band offsets for the HfO_2/Ge abrupt interface indicated that effective barriers exist to inhibit carrier injection.