In this article, electron trapping in aluminum oxide (Al₂O₃) thin films grown by plasma enhanced atomic layer deposition on AlGaN/GaN heterostructures has been studied and a correlation with the presence of oxygen defects in the film has been provided. Capacitance–voltage measurements revealed the occurrence of a negative charge trapping effect upon bias stress, able to fill an amount of charge traps in the bulk Al₂O₃ in the order of 5 × 10¹² cm⁻². A structural analysis based on electron energy-loss spectroscopy demonstrated the presence of low-coordinated Al cations in the Al₂O₃ film, which is an indication of oxygen vacancies, and can explain the electrical behavior of the film. These charge trapping effects were used for achieving thermally stable (up to 100 °C) enhancement mode operation in AlGaN/GaN transistors, by controlling the two-dimensional electron gas depletion.

中文翻译：

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等离子体增强原子层沉积法沉积Al2O3薄膜中的电子俘获与结构缺陷的相关性

在本文中，已经研究了通过在AlGaN / GaN异质结构上进行等离子体增强原子层沉积而生长的氧化铝（Al ₂ O ₃）薄膜中的电子俘获，并提供了与薄膜中氧缺陷的存在的相关性。电容电压测量表明，在偏压力下会出现负电荷俘获效应，能够以5×10 ¹² cm ^-2的量填充块状Al ₂ O ₃中的电荷陷阱。基于电子能量损失谱的结构分析表明，Al ₂ O _3中存在低配位的Al阳离子膜，这是氧空位的指示，可以解释膜的电行为。通过控制二维电子气的耗尽，这些电荷俘获效应被用于在AlGaN / GaN晶体管中实现热稳定（高达100°C）的增强模式操作。