Proton Irradiation Effects in MOCVD Grown β-Ga<sub>2</sub>O<sub>3</sub> and ε-Ga<sub>2</sub>O<sub>3</sub> Thin Films
Jianying Yue, Shan Li, Qi Song, Xueqiang Ji, Zhenping Wu, Peigang Li, Weihua Tang
Abstract
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 xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ga2O3 and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <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 xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times 10^{{11}}$ </tex-math></inline-formula> cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <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 xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <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 xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\varepsilon $ </tex-math></inline-formula> -Ga2O3-based photodetectors could still detect the solar-blind light signal sensitively. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ga2O3 and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <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.