Quasi-two-dimensional (2D) β-Ga₂O₃ is a rediscovered metal-oxide semiconductor with an ultra-wide bandgap of 4.6–4.9 eV. It has been reported to be a promising material for next-generation power and radio frequency electronics. Field effect transistors (FETs) that can switch at high voltage are key components in power and radio frequency devices, and reliable Ohmic contacts are essential for high FET performance. However, obtaining low contact resistance on β-Ga₂O₃ FETs is difficult since reactions between β-Ga₂O₃ and metal contacts are not fully understood. Herein, we experimentally demonstrate the importance of reactions at the metal/β-Ga₂O₃ interface and the corresponding effects of these reactions on FET performance. When Ti is employed as the metal contact, annealing of β-Ga₂O₃ FETs in argon can effectively transform Schottky contacts into Ohmic contacts and permit a large drain current density of ~ 3.1 mA/μm. The contact resistance (R_contact) between the Ti electrodes and β-Ga₂O₃ decreased from ~ 430 to ~ 0.387 Ω·mm after annealing. X-ray photoelectron spectroscopy (XPS) confirmed the formation of oxygen vacancies at the Ti/β-Ga₂O₃ interface after annealing, which is believed to cause the improved FET performance. The results of this study pave the way for greater application of β-Ga₂O₃ in electronics.

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准二维（2D）的β-Ga ₂ ö ₃是一个重新发现的金属氧化物半导体与4.6-4.9电子伏特的超宽带隙。据报道，它是用于下一代电源和射频电子产品的有前途的材料。可以在高电压下切换的场效应晶体管（FET）是功率和射频设备中的关键组件，而可靠的Ohmic触点对于实现高FET性能至关重要。然而，上的β-Ga获得低的接触电阻_2级ö ₃的FET是困难的，因为的β-Ga之间的反应₂ ö ₃和金属触头尚不完全清楚。在此，我们在实验上证实在金属/反应的重要性的β-Ga ₂ ö ₃界面以及这些反应对FET性能的相应影响。若Ti被用作金属接触，β-Ga中退火_2级ö ₃的FET在氩气能有效地变换肖特基接触到欧姆接触，并允许〜3.1毫安个/μm的大的漏电流密度。的接触电阻（ř_接触）在Ti电极和的β-Ga之间₂ ö ₃从〜430到〜下降0.387Ω·退火后毫米。X射线光电子能谱（XPS）确认，在钛/氧空位的形成的β-Ga ₂ ö ₃退火后的界面，这被认为可以改善FET性能。本研究的结果铺路的β-Ga的更大的应用₂ ö ₃中的电子设备。

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