Investigation on Electrical Performance Degradation Mechanism of β-Ga₂O₃ Schottky Barrier Diodes Under 3 MeV Proton Radiation
Shaozhong Yue, Xuefeng Zheng, Fang Zhang, Yuehua Hong, Yingzhe Wang, Tian Zhu, Sunyan Gong, Xiaohu Wang, Ling Lv, Yanrong Cao, Weidong Zhang, Jianfu Zhang, Xiaohua Ma, Yue Hao
Abstract
The influence of proton radiation on the electrical performance of the gallium oxide (Ga2O3) Schottky barrier diode (SBD) was investigated from the perspective of defect in this work. The electrical performance is significantly degraded with the increase of proton irradiation fluence. After the irradiation fluence of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 10^{{13}}$ </tex-math></inline-formula> p/cm2, it was found that the ON-state current density (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {on}}$ </tex-math></inline-formula>) was reduced by 57%, the OFF-state current density (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {off}}$ </tex-math></inline-formula>) was reduced by more than one order of magnitude, and the breakdown voltage (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {br}}$ </tex-math></inline-formula>) increased by nearly 350 V. Based on the frequency-dependent conductance technique, the Ni/Ga2O3 interface changed slightly after proton irradiation. In addition, the deep-level transient spectroscopy (DLTS) measurements show that the concentration of the deep-level defect (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{c}$ </tex-math></inline-formula>-0.75 eV) within the Ga2O3 drift layer has a clear response to radiation, and was significantly increased from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.1\times 10^{{13}}$ </tex-math></inline-formula> cm-3 to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5.4\times 10^{{14}}$ </tex-math></inline-formula> cm-3 after the irradiation with a fluence of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 10^{{13}}$ </tex-math></inline-formula> cm-2. Moreover, the carrier concentration extracted by capacitance-voltage (C–V) shows that the carrier removal rate caused by this defect is 550 cm-1. Considering the change of electrical performance, it indicates that the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{c}$ </tex-math></inline-formula>-0.75 eV defect within the Ga2O3 drift layer rather than the interface state determines the degradation of devices.