Modulation of the two-dimensional electron gas channel in flexible AlGaN/GaN high-electron-mobility transistors by mechanical bending
Modulation of the two-dimensional electron gas channel in flexible AlGaN/GaN high-electron-mobility transistors by mechanical bending
复制标题
机械弯曲对柔性AlGaN/GaN高电子迁移率晶体管二维电子气通道的调制
DOI：
10.1063/1.5142546
复制
发表时间：
2020-03
影响因子：
4
通讯作者：
Weijie Wang;Jie Chen;J. S. Lundh;Shahab Shervin;S. Oh;S. Pouladi;Zhoulyu Rao;Ja Yeon Kim;M. Kwon;Xiaohang Li;Sukwon Choi;J. Ryou
中科院分区：
文献类型：
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作者：
Weijie Wang;Jie Chen;J. S. Lundh;Shahab Shervin;S. Oh;S. Pouladi;Zhoulyu Rao;Ja Yeon Kim;M. Kwon;Xiaohang Li;Sukwon Choi;J. Ryou
采用机械弯曲的方法研究了应变对柔性Al0.25Ga0.75N/GaN高电子迁移率晶体管(HEMT)二维电子气(2DEG)沟道的影响，以验证主动极化工程的概念，从而制造出由柔性III族氮化物薄膜制成的多功能电子和光子器件。柔性HEMT是通过层转移工艺制造的，并与150μm厚的铜膜集成在一起。在4厘米弯曲和−4厘米弯曲测试条件下，通过高分辨率X射线衍射和拉曼光谱估计应变值。应变诱导压电极化可以改变AlGaN/GaN界面沟道中2DEG的电荷密度，从而改变柔性HEMT的输出特性。相应地，输出特性显示在弯曲条件下输出电流增加3.4%，在弯曲条件下减少4.3%。传输特性表现出阈值电压的漂移，这也支持弯曲过程中的2DEG沟道调制。基于相同结构的计算仿真证实了相同的电流调制效果和阈值电压漂移。此外，柔性HEMT的电学特性表现出对应变效应的可重复依赖性，这为机电器件的应用提供了潜力。
We investigate the effect of strain on the two-dimensional electron gas (2DEG) channel in a flexible Al0.25Ga0.75N/GaN high-electron-mobility transistor (HEMT) by mechanical bending to prove the concept of active polarization engineering to create multifunctional electronic and photonic devices made of flexible group III-nitride thin films. The flexible HEMTs are fabricated by a layer-transfer process and integrated with a 150-μm-thick Cu film. The strain values are estimated from high-resolution x-ray diffraction and Raman spectroscopy in 4-cm bend-down and −4-cm bend-up test conditions. The strain-induced piezoelectric polarization can alter the charge density of the 2DEG in the channel at the AlGaN/GaN interface and thus modify the output characteristics of the flexible HEMTs. Accordingly, output characteristics show an increase in output current by 3.4% in the bend-down condition and a decrease by 4.3% in the bend-up condition. Transfer characteristics show a shift of threshold voltage, which also supports the 2DEG channel modulation during bending. Computational simulation based on the same structure confirms the same current modulation effect and threshold voltage shift. Furthermore, the electrical characteristics of the flexible HEMTs show a repeatable dependence on the strain effect, which offers potential for electro-mechanical device applications.