MBE growth techniques for InAs-based nBn IR detectors
MBE growth techniques for InAs-based nBn IR detectors
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DOI：
10.1116/1.4978389
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发表时间：
2017-03
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通讯作者：
D. Sidor;G. Savich;B. Marozas;X. Du;Trevor A. O'Loughlin;G. Jenkins;William D. Hughes;C. Morath;V. Cowan;G. Wicks
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作者：
D. Sidor;G. Savich;B. Marozas;X. Du;Trevor A. O'Loughlin;G. Jenkins;William D. Hughes;C. Morath;V. Cowan;G. Wicks
研究了生长温度对分子束外延(MBE)生长的InAs外延层和InAs基NbN探测器的影响。这项工作的动机是提高InAs基NBN探测器的整体性能，这既取决于单个器件层的整体材料质量，特别是红外吸收层，也取决于层界面的质量，特别是吸收层和阻挡层之间的界面质量。吸收层整体质量和吸收层/势垒界面质量可能是通过在不同温度下进行InAs生长来优化的，因此首选的MBE生长策略并不是一目了然的。在420C到490C的不同温度下生长了厚度为2μm的InAs外延层，并用差示干涉显微镜、原子力显微镜、稳态光致发光和时间分辨光致发光测量对其进行了检测。NbN探测器中2μm厚的吸收体层也是在与InAs单层相同的温度下生长的，所得到的器件是基于暗电流密度进行评估的。在所研究的生长温度范围内，已经实现了具有竞争力的高InAs材料质量和低的NBN暗电流密度。在所研究的温度范围内，InAs单层外延层的材料质量随着生长温度的升高而单调提高，而NbN探测器的反饱和暗电流密度也随着生长温度的升高而单调下降。报道了暗电流密度在规则07的5倍以内的NbN探测器。最后指出，本工作使用了0.9μm/h的InAs生长速率，而许多其他研究选择使用0.2-0.5μm/h的InAs生长速率。本研究的结果表明，高性能的InAs基探测器可以在这种更方便的速率下生长。本文描述了生长温度对InAs外延层和分子束外延生长的InAs基NbN探测器的影响。这项工作的动机是提高InAs基NBN探测器的整体性能，这既取决于单个器件层的整体材料质量，特别是红外吸收层，也取决于层界面的质量，特别是吸收层和阻挡层之间的界面质量。吸收层整体质量和吸收层/势垒界面质量可能是通过在不同温度下进行InAs生长来优化的，因此首选的MBE生长策略并不是一目了然的。在420C到490C的不同温度下生长了厚度为2μm的InAs外延层，并用差示干涉显微镜、原子力显微镜、稳态光致发光和时间分辨光致发光测量对其进行了检测。吸收层厚度为2μm。
This manuscript describes an investigation of the effects of growth temperature on InAs epitaxial layers and InAs-based nBn detectors grown by molecular beam epitaxy (MBE). The motivation for this work is to improve the overall performance of InAs-based nBn detectors, which depends both on the bulk material quality of the individual device layers, particularly the infrared absorbing layer, as well as on the quality of the layer interfaces, particularly the interface between the absorber and barrier layers. Absorber layer bulk quality and absorber/barrier interface quality are presumably optimized by performing InAs growth at different temperatures, thus the preferred MBE growth strategy is not immediately apparent. InAs epitaxial layers of 2 μm thick are grown at several temperatures ranging from 420 to 490 °C, and are examined by differential interference contrast microscopy, atomic force microscopy, steady-state photoluminescence, and time-resolved photoluminescence measurements. Absorber layers of 2 μm thick in nBn detectors are also grown at the same temperatures as the InAs single layers, and the resulting devices are evaluated on the basis of dark current density. Competitively high InAs material quality and low nBn dark current densities have been achieved across the range of investigated growth temperatures. The material quality of the InAs single epitaxial layers is found to improve monotonically with growth temperature over the investigated range, and likewise, the reverse saturation dark current density of the nBn detectors is found to decrease monotonically with growth temperature. nBn detectors with dark current density within a factor of 5 of Rule 07 are reported. Finally, it is noted that this work uses an InAs growth rate of 0.9 μm/h, whereas many other studies have chosen to use InAs growth rates in the range of 0.2–0.5 μm/h. The results of this study demonstrate that high performance InAs-based detectors can be grown at this more convenient rate.This manuscript describes an investigation of the effects of growth temperature on InAs epitaxial layers and InAs-based nBn detectors grown by molecular beam epitaxy (MBE). The motivation for this work is to improve the overall performance of InAs-based nBn detectors, which depends both on the bulk material quality of the individual device layers, particularly the infrared absorbing layer, as well as on the quality of the layer interfaces, particularly the interface between the absorber and barrier layers. Absorber layer bulk quality and absorber/barrier interface quality are presumably optimized by performing InAs growth at different temperatures, thus the preferred MBE growth strategy is not immediately apparent. InAs epitaxial layers of 2 μm thick are grown at several temperatures ranging from 420 to 490 °C, and are examined by differential interference contrast microscopy, atomic force microscopy, steady-state photoluminescence, and time-resolved photoluminescence measurements. Absorber layers of 2 μm...