Growth, microstructure and morphology of epitaxial ScGaN films
Growth, microstructure and morphology of epitaxial ScGaN films
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外延ScGaN薄膜的生长、微观结构和形貌
DOI：
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
M. Moram
中科院分区：
文献类型：
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作者：
S. M. Knoll;Siyuan Zhang;T. Joyce;M. Kappers;C. Humphreys;M. Moram
采用NH3分子束外延（MBE）技术在GaN - on -蓝宝石衬底上生长了ScGaN外延薄膜。通过模拟和拟合0002 ω-2θ X射线衍射图，所有薄膜的Sc含量都保持在2%以下，而高分辨率X射线衍射没有检测到与纤锌矿结构的偏差。随着Sc通量的增加，ScGaN的生长速率显著下降，与相似条件下生长的GaN的生长速率相比，ScGaN的生长速率仍然较低，而Sc掺入率即使在Sc积液细胞温度高达1400℃时仍然很低。原子力显微镜（AFM）高度图像表明，较高的Sc通量与改善的膜聚结有关。这些数据表明，在生长过程中，表面活性剂Sc层可能存在于薄膜表面。Sc含量较低的薄膜的位错密度与底层GaN的位错密度相似，尽管在Sc含量较高的薄膜中观察到a组分的弯曲和引入额外的位错。在Sc含量较高的ScGaN薄膜中，还观察到由棱柱状层错连接的基面层错，在580 nm附近有宽的发光带。
Epitaxial ScGaN films were grown on GaN‐on‐sapphire substrates by NH3‐molecular beam epitaxy (MBE). The Sc content remained below 2% for all films, as determined by the simulation and fitting of 0002 ω–2θ X‐ray diffractograms, while no deviation from the wurtzite structure was detected using high resolution X‐ray diffraction. ScGaN growth rates decreased significantly as the Sc flux increased and remained low compared to the growth rates of GaN grown under similar conditions, while Sc incorporation rates remained low even at Sc effusion cell temperatures as high as 1400 °C. Atomic force microscopy (AFM) height images indicate that higher Sc fluxes are associated with improved film coalescence. These data indicate that a surfactant layer of Sc may be present at the film surface during growth. The dislocation density of the lower Sc content films was similar to that of the underlying GaN, though the bending and introduction of additional dislocations with an a‐component was observed for higher Sc contents. Basal plane stacking faults connected by prismatic stacking faults were also observed, in higher Sc‐content ScGaN films, along with a broad luminescence band near 580 nm.
影响因子：
1.8
作者：
M. Moram;S. Novikov;A. Kent;C. Nörenberg;C. T. Foxon;C. Humphreys
通讯作者：
M. Moram;S. Novikov;A. Kent;C. Nörenberg;C. T. Foxon;C. Humphreys
影响因子：
2.1
作者：
Moram, M. A.;Barber, Z. H.;Humphreys, C. J.
通讯作者：
Humphreys, C. J.