Characterisation of thin-layer resonant tunnelling diodes grown by MOVPE
Characterisation of thin-layer resonant tunnelling diodes grown by MOVPE
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MOVPE 生长的薄层谐振隧道二极管的表征
DOI：
10.1117/12.2510119
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Richard A Hogg
中科院分区：
文献类型：
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作者：
Razvan Baba;Osamu Kojima;Kristof JP Jacobs;Brett A Harrison;Ben J Stevens;Toshikazu Mukai;Richard A Hogg
谐振隧道二极管 (RTD) 是核心太赫兹生成技术的下一代候选者，具有经过验证的准光可调发射能力，在 cca 时中心频率为 0.1 - 1.98 太赫兹。 1mW，当耦合到合适的单片集成天线时。为此，应变 InGaAs/AlAs/InP 材料系统已接近技术成熟，具有高电子迁移率、合适的导带偏移和极低电阻接触。然而，用于 RTD 的外延薄层可实现电流密度超过 10 mAμm-2 且电场接近材料击穿强度的器件。由于高电流密度是这些振荡器性能的传统指标，因此现在生长接近原子完美的晶体层变得越来越重要。在之前的工作中，我们展示了包含名义上相同、未掺杂的 RTD 双势垒 - 量子阱 (QW) 系统的电中性副本如何导致除了有源区 QW 的 I 型发射之外还观察到 II 型 QW 发射。这可用于建立准束缚弹性能，其水平与 N 形 I-V 特性的峰值电压直接相关。在这里，我们通过添加高分辨率 X 射线衍射法和低温光致发光光谱法来扩展这种方法。通过逐步的曲线拟合过程，与模拟和结果进行比较，我们可以评价 AlAs 势垒周围三元 InGaAs 合金界面的质量和厚度。这些发现通过扫描透射电子显微镜得到证实
Resonant tunneling diodes (RTDs) are next-generation candidates for core THz generation technologies, with proven quasi-optical tunable emission capability, with centre frequencies of 0.1 - 1.98 THz at cca. 1mW, when coupled into a suitable monolithically integrated antenna. For this purpose, the strained InGaAs/AlAs/InP material system is approaching technological maturity, with its offering of high electron mobility, suitable conduction band offsets, and very low resistance contacts. However, the epitaxially thin layers used for RTDs, realise devices with current densities in excess of 10 mAμm-2and electric fields approaching that of the breakdown of the material. As a high current density is a traditional indicator of performance for these oscillators, it is now increasingly important to grow crystalline layers with near-atomic perfection. In previous work, we showed how the inclusion of a nominally identical, un-doped electrically neutral copy of the RTD double barrier - quantum well (QW) system, leads to the observance of a type-II QW emission in addition to the type-I emission from the active region QW. This could be used to establish the quasi-bound elastic energy, whose level is directly correlated to the peak voltage of the N-shape I-V characteristic. Here we extend this approach with the addition of high-resolution X-ray diffractometry and low-temperature photoluminescence spectroscopy. Through a step-by-step process of curve fitting, comparing to simulation and results, we can comment on the quality and thickness of the ternary InGaAs alloy interfaces surrounding the AlAs barriers. These findings are confirmed with scanning transmission electron microscopy