High-temperature thermal stability study of 1nm Al_2O_3 deposited on InAs surfaces investigated by synchrotron radiation based photoemission spectroscopy

摘要

High-resolution soft x-ray photoemission spectroscopy (SXPS) has been used to study the high-temperature thermal stability of ultra-thin atomic layer deposited (ALD) Al_2O_3 layers (～1 nm) on sulfur passivated and native oxide covered InAs surfaces. While the arsenic oxides were removed from both interfaces following a 600 ℃ anneal, a residual indium oxide signal remained. No significant differences were observed between the sulfur passivated and native oxide surfaces other than the thickness of the interfacial oxide layer while the Al_2O_3 stoichiometry remained unaffected by the anneals. The energy band offsets were determined for the Al_2O_3 on the sulfur passivated InAs surface using both valence band edge and shallow core-level photoemission measurements.