Growth of single-phase nanostructured Er2O3 thin films on Si (100) by ion beam sputter deposition

•The reaction mechanism between Er silicides and Er oxides was elucidated.•Single-phase Er2O3 thin films were firstly fabricated by ion beam sputter deposition.•Epitaxial relationship between Si (100) and Er2O3 (110) was verified.•Single-phase Er2O3 thin films possess single crystalline structures of bulk Er2O3.

Single-phase nanocrystalline thin films of Er2O3 (440) has been first prepared using Si (100) substrates by ion beam sputter deposition at 700 °C at a pressure of < 10− 7 Torr and in-situ annealing at 750 °C at a pressure of < 10− 9 Torr. Er silicides formed during the deposition are eliminated via the annealing, which results in the single phase and the smooth surface of the Er2O3 thin films. The epitaxial relationship between Si (100) and Er2O3 (110) is clarified by X-ray diffraction and reflection high energy electron diffraction. The silicide phase of ErSi2 appears again when an annealing temperature is higher than 800 °C.