Abstract

The trap states at ultraviolet/ozone (UV/O₃)-treated Al₂O₃/GaN interfaces of p-type metal-oxide-semiconductor capacitors (pMOSCAPs) are analyzed through a frequency-dispersion capacitance–voltage (C–V) measurements. X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy are applied to confirm a formation of ultrathin oxide layer (Ga₂O_x) on GaN surface by the UV/O₃ treatment. The trapped charge density and interface trap density improved from 7.30 × 10¹¹ to 2.79 × 10¹¹ cm⁻² eV⁻¹ averaged over the bandgap of GaN and from 1.28 × 10¹³ to 4.08 × 10¹² cm⁻² eV⁻¹ near the conduction band edge of GaN, respectively, owing to the passivation of Ga₂O_x layer at the Al₂O₃/GaN interfaces. Mechanism for the improved trap states in pMOSCAPs is identified based on the reduced defect states at both Al₂O₃/Ga₂O_x and Ga₂O_x/GaN interfaces.

Graphic Abstract

中文翻译：

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通过频率色散电容-电压测量分析具有紫外/臭氧处理的GaN接口的p-金属氧化物半导体电容器中的陷阱状态

抽象的

通过频率色散电容-电压（C–V）分析了p型金属氧化物半导体电容器（pMOSCAPs）在紫外线/臭氧（UV / O ₃）处理的Al ₂ O ₃ / GaN界面处的陷阱态。测量。应用X射线光电子能谱和高分辨率透射电子显微镜来确认通过UV / O ₃处理在GaN表面形成了超薄氧化层（Ga ₂ O _x）。GaN的带隙平均电荷俘获密度和界面陷阱密度从7.30×10 ¹¹提高到2.79×10 ¹¹  cm ^-2  eV ^-1，从1.28×10 ^13提高到由于在Al ₂ O ₃ / GaN界面处的Ga ₂ O _x层被钝化，在GaN的导带边缘附近分别达到4.08×10 ¹²  cm ^-2  eV ^-1。基于Al ₂ O ₃ / Ga ₂ O _x和Ga ₂ O _x / GaN界面处的减少的缺陷状态，确定了pMOSCAP中改善的陷阱状态的机制。

图形摘要