Analyses of hetero-interface trapping properties in AlGaN/GaN high electron mobility transistor heterostructures grown on silicon with thick buffer layers
Analyses of hetero-interface trapping properties in AlGaN/GaN high electron mobility transistor heterostructures grown on silicon with thick buffer layers
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DOI：
10.1063/1.4733359
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发表时间：
2012-07
影响因子：
4
通讯作者：
J. Freedsman;T. Kubo;T. Egawa
中科院分区：
文献类型：
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作者：
J. Freedsman;T. Kubo;T. Egawa
本文报道了金属-有机化学气相沉积生长的AlGaN/GaN高电子迁移率晶体管（HEMT）异质结构随着缓冲层厚度（Tbuff）的增加而被捕获的特性。在阈值电压附近，AlGaN/GaN异质界面阱时间常数与栅极偏置呈指数关系。用厚Tbuff ~ 5 μm生长的异质结构的Dit值为~ 2.5 × 1010 cm−2 eV−1，而用薄Tbuff ~ 1.25 μm生长的异质结构的Dit值为~ 1 × 1011 cm−2 eV−1。此外，高分辨率x射线摇摆曲线和Van der Pauw-Hall测量也证实，增加Tbuff可以改善AlGaN/GaN HEMT异质结构，降低边缘位错密度，增强载流子输运性能。
We report on the analyses of trapping properties of metal-organic chemical vapor deposition grown AlGaN/GaN high-electron-mobility transistor (HEMT) heterostructures on silicon with increasing buffer thickness (Tbuff). An exact exponential dependence of AlGaN/GaN hetero-interface trap time constants with gate bias was observed in the vicinity of threshold voltage. A low hetero-interface state density (Dit) value of ∼2.5 × 1010 cm−2 eV−1 was achieved for heterostructures grown by using thick Tbuff ∼ 5 μm against a Dit value of ∼1 × 1011 cm−2 eV−1 for a similar heterostructures grown with thin Tbuff ∼ 1.25 μm. Further, the high resolution x-ray rocking curve and Van der Pauw-Hall measurements also confirmed that increasing the Tbuff improves the AlGaN/GaN HEMT heterostructures with reduced edge dislocation densities and enhanced carrier transport properties.