Amir Walid, Chakraborty Surajit, Kwon Hyuk-Min, Kim Tae-Woo
Department of Electrical, Electronic and Computer Engineering, University of Ulsan, Ulsan 44610, Republic of Korea.
Department of Semiconductor Processing Equipment, Semiconductor Convergence Campus, Korea Polytechnics, Anseong-si 17550, Republic of Korea.
Materials (Basel). 2023 Jun 19;16(12):4469. doi: 10.3390/ma16124469.
In this study, we present a detailed analysis of trapping characteristics at the AlGaN/GaN interface of AlGaN/GaN high-electron-mobility transistors (HEMTs) with reliability assessments, demonstrating how the composition of the Al in the AlGaN barrier impacts the performance of the device. Reliability instability assessment in two different AlGaN/GaN HEMTs [x = 0.25, 0.45] using a single-pulse characterization technique revealed higher drain-current degradation (∆) with pulse time for AlGaN/GaN devices which correlates to the fast-transient charge-trapping in the defect sites near the interface of AlGaN/GaN. Constant voltage stress (CVS) measurement was used to analyze the charge-trapping phenomena of the channel carriers for long-term reliability testing. AlGaN/GaN devices exhibited higher-threshold voltage shifting (∆) caused by stress electric fields, verifying the interfacial deterioration phenomenon. Defect sites near the interface of the AlGaN barrier responded to the stress electric fields and captured channel electrons-resulting in these charging effects that could be partially reversed using recovery voltages. The quantitative extraction of volume trap density () using 1/ low-frequency noise characterizations unveiled a 40% reduced for the AlGaN/GaN device, further verifying the higher trapping phenomena in the AlGaN barrier caused by the rougher AlGaN/GaN interface.
在本研究中，我们对具有可靠性评估的AlGaN/GaN高电子迁移率晶体管（HEMT）的AlGaN/GaN界面处的俘获特性进行了详细分析，展示了AlGaN势垒中Al的组成如何影响器件性能。使用单脉冲表征技术对两种不同的AlGaN/GaN HEMT[x = 0.25, 0.45]进行可靠性不稳定性评估，结果表明，AlGaN/GaN器件的漏极电流退化（∆）随脉冲时间增加，这与AlGaN/GaN界面附近缺陷位点的快速瞬态电荷俘获有关。采用恒压应力（CVS）测量来分析沟道载流子的电荷俘获现象，以进行长期可靠性测试。AlGaN/GaN器件表现出由应力电场引起的更高阈值电压偏移（∆），证实了界面劣化现象。AlGaN势垒界面附近的缺陷位点对应力电场作出响应并俘获沟道电子，导致这些充电效应可通过恢复电压部分逆转。使用1/低频噪声表征对体陷阱密度（）进行定量提取，结果表明AlGaN/GaN器件的降低了40%，进一步证实了AlGaN/GaN界面粗糙度导致AlGaN势垒中更高的俘获现象。
