Title: Effects of post-deposition annealing in oxygen ambient of RF magnetron sputtered Ga₂O₃ thin film

Authors: Puteri Haslinda Megat Abdul Hedei; Zainuriah Hassan; Hock Jin Quah

Addresses: Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia, 11800 Penang, Malaysia ' Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia, 11800 Penang, Malaysia ' Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia, 11800 Penang, Malaysia

Abstract: An investigation on the radio frequency magnetron sputtered gallium oxide (Ga₂O₃) thin films on Si (100) subjected to different post-deposition annealing temperatures of 400, 600, 800, and 1000°C for 60 min in oxygen ambient was carried out in this work. Grazing incidence X-ray diffraction (GIXRD) revealed the formation of polycrystalline Ga₂O₃ thin films with an improvement in crystalline quality as the post-deposition annealing temperature was enhanced from 400 to 1000°C. The improvement in crystalline quality of Ga₂O₃ thin films was related to a reduction in the concentration of oxygen vacancies, wherein energy-dispersive X-ray spectroscopy has revealed an increment in atomic percentage of oxygen from 62.63 to 66.66 as a function of post-deposition annealing temperature. The changes from compressive to tensile microstrain induced on the investigated Ga₂O₃ thin films during post-deposition annealing at/beyond 800°C have revealed the occupancy of more oxygen vacancies. Thus, an increment in values of direct and indirect bandgap of Ga₂O₃ thin films was attained with respect to post-deposition annealing temperature. Nonetheless, it was perceived that the formation of interfacial layer was exaggerated at 1000°C, wherein an exceptionally low leakage current density has been demonstrated by Ga₂O₃ thin films annealed at 1000°C.

Keywords: gallium oxide; silicon; sputtering; grazing incidence X-ray diffraction; annealing; MOS; oxygen.

DOI: 10.1504/IJNT.2022.124502

International Journal of Nanotechnology, 2022 Vol.19 No.2/3/4/5, pp.211 - 222

Published online: 27 Jul 2022 *

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