Proton Irradiation Effects in MOCVD Grown β-Ga2O3 and ε-Ga2O3 Thin Films

• Published in: IEEE transactions on nuclear science Vol. 71; no. 1; pp. 67 - 71
• Main Authors: Yue, Jian-Ying, Li, Shan, Qi, Song, Ji, Xue-Qiang, Wu, Zhen-Ping, Li, Pei-Gang, Tang, Wei-Hua
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.01.2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Crystal defects; Crystals; Epitaxial growth; Gallium; Gallium oxide; Gallium oxides; Irradiation; Metalorganic chemical vapor deposition; metal–organic chemical vapor deposition (MOCVD); MOCVD; Optical properties; Organic chemicals; Organic chemistry; photodetector; Photodetectors; Photoelectric effect; Photoelectric properties; Photoelectricity; Photometers; Proton irradiation; Proton radiation effects; Protons; Radiation; Radiation damage; Radiation tolerance; Semiconductor devices; Space applications; Surface morphology; Surface properties; Thin films; β-gallium oxide (Ga₂O₃); ε-Ga₂O
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2023.3337389

Gallium oxide (Ga2O3) with robust bonding is advantageous for space applications, but its radiation hardness dependent on the crystalline phases has not been reported yet. Herein, the proton irradiation effects on <inline-formula> <tex-math notation="LaTeX">\beta </tex-math></inline-formula>-Ga2O3 and <inline-formula> <tex-math notation="LaTeX">\varepsilon </tex-math></inline-formula>-Ga2O3 epitaxial films grown by metal-organic chemical vapor deposition (MOCVD) have been observed at 100 MeV with proton fluences up to <inline-formula> <tex-math notation="LaTeX">1\times 10^{{11}} </tex-math></inline-formula> cm<inline-formula> <tex-math notation="LaTeX">^{-{2}} </tex-math></inline-formula>. The film crystallinity, surface quality, optical property, and defect concentration were measured from Ga2O3 with and without proton irradiation. Additionally, the metal-semiconductor-metal (MSM)-type photodetectors were constructed on the non-irradiated and proton-irradiated <inline-formula> <tex-math notation="LaTeX">\beta </tex-math></inline-formula>-/<inline-formula> <tex-math notation="LaTeX">\varepsilon </tex-math></inline-formula>-Ga2O3 thin films to investigate radiation damage of photodetection performance. Although the proton irradiation may generate some possible irradiation defects (such as self-trapped holes or vacancies) in Ga2O3 thin films to degrade their photoelectric properties, the <inline-formula> <tex-math notation="LaTeX">\beta </tex-math></inline-formula>-/<inline-formula> <tex-math notation="LaTeX">\varepsilon </tex-math></inline-formula>-Ga2O3-based photodetectors could still detect the solar-blind light signal sensitively. <inline-formula> <tex-math notation="LaTeX">\beta </tex-math></inline-formula>-Ga2O3 and <inline-formula> <tex-math notation="LaTeX">\varepsilon </tex-math></inline-formula>-Ga2O3 are materials for semiconductor devices regarding future space applications for their favorable resistance to radiation.