Atomic layer deposited (ALD) aluminum oxide (Al₂O₃) has emerged as a useful material for silicon devices due to its capability for effective surface passivation and ability to generate p⁺ region underneath the oxide as active or passive component in semiconductor devices. However, it is uncertain how Al₂O₃ films tolerate the so-called Al-neal treatment that is a necessary process step in devices that also contain silicon dioxide (SiO₂) passivation layers. Herein, it is reported that the Al-neal process is harmful for the passivation performance of Al₂O₃ causing over eightfold increase in surface recombination velocity (SRV) (from 0.9 to 7.3 cm s⁻¹). Interestingly, it is also observed that the stage at which the so-called activation of Al₂O₃ passivation is performed impacts the final degradation strength. The best result is obtained when the activation step is done at the end of the process together with the Al-neal thermal treatment, which results in SRV of 1.7 cm s⁻¹. The results correlate well with the measured interface defect density, indicating that the Al-neal affects defects at the Si/SiO _x /Al₂O₃ interface. The root causes for the defect reactions are discussed and possible reasons for the observed phenomena are suggested.

中文翻译：

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Al-neal 降低硅表面的 Al2O3 钝化

原子层沉积 (ALD) 氧化铝 (Al ₂ O ₃ ) 已成为硅器件的有用材料，因为它具有有效的表面钝化能力以及在氧化物下方生成 p ⁺区作为半导体器件中的有源或无源组件的能力。然而，尚不确定 Al ₂ O ₃薄膜如何耐受所谓的 Al 退火处理，该处理是还包含二氧化硅 (SiO ₂ ) 钝化层的器件中的必要工艺步骤。在此，据报道，Al-neal 工艺对 Al ₂ O ₃的钝化性能有害导致表面复合速度 (SRV) 增加八倍以上（从 0.9 到 7.3 cm s ^-1）。有趣的是，还观察到进行所谓的 Al ₂ O ₃钝化活化的阶段会影响最终降解强度。当活化步骤与Al-neal热处理一起在工艺结束时完成时获得最佳结果，这导致SRV为1.7 cm s ^-1。结果与测量的界面缺陷密度相关性很好，表明 Al-neal 影响 Si/SiO _x /Al ₂ O ₃处的缺陷 界面。讨论了缺陷反应的根本原因，并建议了观察到的现象的可能原因。