We demonstrate effective reduction of interface states and current collapse in AlGaN/GaN metal insulator semiconductor heterostructure field effect transistor (MISHFETs) with Al₂O₃ and in-situ AlN passivation layer. Here, first, a 3 nm-thick in-situ AlN layer is grown on AlGaN/GaN structure by using MOCVD at 1070 °C, and second a 7 nm-thick atomic layer deposition (ALD) Al₂O₃ layer is immediately deposited on the AlN layer. The X-ray photoelectron spectroscopy (XPS) analyses for the Ga 3d core level and multi-frequency capacitance−voltage (C−V) measurement show that the density of interface states originated from the Ga-O bonds, which is dramatically reduced with the in-situ AlN passivation layer. The AlGaN/GaN-based MISHFET with the Al₂O₃/in-situ AlN layers exhibits the low gate-lag effect (8%), remarkably less than that of the device with the typical GaN capping layer (21.5%). These results indicate that the Al₂O₃/in-situ AlN double passivation layer is very effective in suppressing the current collapse, and hence, it is found to be the promising method for the fabrication of AlGaN/GaN MISHFETs with enhanced performance.

我们证明了具有Al ₂ O ₃和原位AlN钝化层的AlGaN / GaN金属绝缘体半导体异质结构场效应晶体管（MISHFET）中界面状态的有效降低和电流崩溃。在此，首先，通过在1070°C下使用MOCVD在AlGaN / GaN结构上生长3 nm厚的原位AlN层，然后立即沉积7 nm厚的原子层沉积（ALD）Al ₂ O ₃层在AlN层上。Ga 3 d的X射线光电子能谱（XPS）分析核心能级和多频电容-电压（C-V）测量表明，界面态的密度源自Ga-O键，而原位AlN钝化层显着降低了界面态的密度。具有Al ₂ O ₃ /原位AlN层的基于AlGaN / GaN的MISHFET表现出较低的栅极滞后效应（8％），明显小于具有典型GaN覆盖层的器件的栅极滞后效应（21.5％）。这些结果表明，Al ₂ O ₃ /原位AlN双钝化层在抑制电流崩塌方面非常有效，因此，发现其是具有增强的性能的AlGaN / GaN MISHFET的制造的有前途的方法。