In situ observation of two-step growth of AlN on sapphire using high-temperature metal-organic chemical vapour deposition
In situ observation of two-step growth of AlN on sapphire using high-temperature metal-organic chemical vapour deposition
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高温金属有机化学气相沉积法原位观察蓝宝石上两步生长AlN
DOI：
10.1039/c3ce40755a
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发表时间：
2013-01-01
期刊：
影响因子：
3.1
通讯作者：
Zhang, Zhiwei
中科院分区：
文献类型：
--
作者：
Sun, Xiaojuan;Li, Dabing;Zhang, Zhiwei
我们研究了AlN的两步生长使用高温（HT）金属有机化学气相沉积（MOCVD）使用405 nm短波长原位监测系统。首先，在1300 ℃下沉积HT-AlN膜之前，在950 ℃下在蓝宝石上生长AlN成核层（NL）。405 nm波长的原位反射瞬态曲线揭示了AlN生长的演变。405 nm信号的反射强度在AlN生长过程中首先下降，然后变得更强，直到它达到一个稳定的状态，在大而等幅值，揭示了AlN生长经历了从核到核分解岛恢复准逐层生长的过渡。利用原位监测系统研究了不同初始生长条件对AlN生长模式的影响。基于405 nm的原位反射曲线和原子力显微镜的观察，提出了薄膜的生长机制。通过优化NL生长条件，我们获得了高质量的AlN/蓝宝石模板，其（0002）和（10-12）面的半峰全宽分别为60 arcsec和550 arcsec。最后在AlN模板上制作了高性能的PIN AlGaN探测器，进一步验证了其高质量。
We studied the two-step growth of AlN using high-temperature (HT) metal-organic chemical vapour deposition (MOCVD) using a 405 nm short-wavelength in situ monitoring system. First, an AlN nucleation layer (NL) was grown on sapphire at 950 degrees C before deposition of the HT-AlN film at 1300 degrees C. The 405 nm wavelength in situ reflectance-transient curves revealed the evolution of AlN growth. The reflectance intensity of the 405 nm signal first decreased during AlN growth and then became stronger until it reached a steady state at large and equal amplitude, revealing that the AlN growth underwent a transition from nuclei to nuclei decomposed island recovery to quasi-layer-by-layer growth. The effect of different initial growth conditions on the AlN growth mode was also studied using the in situ monitoring system. The growth mechanism for the films was proposed based on the 405 nm in situ reflectance curves and atomic force microscopy observations. By optimizing the NL growth conditions, we obtained a high-quality AlN/sapphire template with full width at half maxima for the (0002) and (10-12) planes of 60 arcsec and 550 arcsec, respectively. Finally, a high performance PIN-AlGaN detector was fabricated on the AlN template, which further demonstrated its high quality.