High-Quality AlN Film Grown on Sputtered AlN/Sapphire via Growth-Mode Modification
High-Quality AlN Film Grown on Sputtered AlN/Sapphire via Growth-Mode Modification
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通过生长模式修改在溅射 AlN/蓝宝石上生长高质量 AlN 薄膜
DOI：
10.1021/acs.cgd.8b01045
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发表时间：
2018-11-01
影响因子：
3.8
通讯作者：
Shen, Bo
中科院分区：
文献类型：
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作者：
He, Chenguang;Zhao, Wei;Shen, Bo
在没有大尺寸、低成本的自然衬底的情况下，高质量的AlN薄膜异质外延是推动深紫外光(DUV)器件繁荣发展的关键。在这里，我们提出了一种结合生长模式修饰和金属-有机化学气相沉积(MOCVD)溅射AlN缓冲层的策略来获得高质量的AlN薄膜。与MOCVD AlN缓冲层相比，溅射AlN缓冲层由更细小、更均匀的颗粒组成，具有更好的c轴取向，在后续的生长过程中有更好的生长模式调整。一方面，较好的c轴取向被上层AlN外延层继承，导致较低的螺位错密度。另一方面，更好的生长模式通过产生高密度的纳米级空位和许多90°弯曲位错显著地抑制了边缘位错。因此，在溅射的AlN缓冲层上生长的AlN薄膜的总穿线位错密度大大降低到极低的值。
Heteroepitaxy of high-quality AlN film is the key to advance the prosperity of deep-ultraviolet (DUV) devices when a large-size and low-cost native substrate is unavailable. Here, we proposed a strategy to obtain high-quality AlN film by combining growth-mode modification with sputtered AlN buffer using metal–organic chemical vapor deposition (MOCVD). Compared with the MOCVD AlN buffer, the sputtered AlN buffer consists of smaller and more uniform grains with better c-axis orientation, leading to a better growth-mode modification in the subsequent growth process. On one hand, the better c-axis orientation is inherited by the upper AlN epilayer, resulting in a lower screw dislocation density. On the other hand, the better growth-mode modification significantly suppresses edge dislocations by producing high-density nanoscale voids and many 90° bent dislocations. Therefore, the total threading dislocation density of the AlN film grown on the sputtered AlN buffer is dramatically reduced to an extremely low va...