The AlN lattice-polarity inversion in a high-temperature-annealed c-oriented AlN/sapphire originated from the diffusion of Al and O atoms from sapphire.
The AlN lattice-polarity inversion in a high-temperature-annealed c-oriented AlN/sapphire originated from the diffusion of Al and O atoms from sapphire.
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DOI：
10.1039/d3na00780d
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发表时间：
2024-01-16
影响因子：
4.7
通讯作者：
Li, Dabing
中科院分区：
文献类型：
--
作者：
Jiang, Ke;Ben, Jianwei;Sun, Xiaojuan;Shi, Zhiming;Wang, Xianjun;Fang, Tong;Zhang, Shanli;Lv, Shunpeng;Chen, Yang;Jia, Yuping;Zang, Hang;Liu, Mingrui;Li, Dabing
AlN薄膜由于其上级特性而被广泛使用，包括超宽带隙、高击穿场和抗辐射性。高温退火（HTA）可以容易地获得高质量的AlN薄膜，具有工艺简单，重复性好，成本低的优点。然而，它总是被发现，有一个晶格极性反转，从N-极性附近的蓝宝石的Al-极性在HTA c-取向的AlN/蓝宝石。目前，其形成机理尚不清楚，阻碍了其进一步的广泛应用。因此，极性反转的形成机制及其对HTA c-取向AlN/蓝宝石中上层AlN的质量和应力分布的影响进行了研究。结果表明，这种反转是由蓝宝石中的Al和O原子扩散引起的。由于上层AlN中存在丰富的Al空位（瓦尔），蓝宝石中的Al原子在退火过程中扩散到上层AlN中填充瓦尔，形成O端蓝宝石，从而形成N极性AlN。同时，蓝宝石中的O原子在退火过程中也扩散到上层AlN中，形成AlxOyNz层，并引起N-极性到Al-极性的反转。反转对上层AlN的质量和应力分布影响不大。此外，本研究预测在反转界面处存在二维电子气。然而，测量的电子浓度远低于预测，这可能是由于缺陷补偿，低极化水平，和强杂质散射。高温退火后c取向AlN/蓝宝石薄膜的极性反转是由于Al和O原子从蓝宝石中扩散而引起的。
AlN films are widely used owing to their superior characteristics, including an ultra-wide bandgap, high breakdown field, and radiation resistance. High-temperature annealing (HTA) makes it easy to obtain high-quality AlN films, with the advantages of a simple process, good repeatability, and low cost. However, it is always found that there is a lattice-polarity inversion from a N-polarity near the sapphire to an Al-polarity in the HTA c-oriented AlN/sapphire. Currently, the formation mechanism is still unclear, which hinders its further wide applications. Therefore, the formation mechanism of the polarity inversion and its impacts on the quality and stress profile of the upper AlN in the HTA c-oriented AlN/sapphire were investigated. The results imply that the inversion originated from the diffusion of the Al and O atoms from the sapphire. Due to the presence of abundant Al vacancies (VAl) in the upper AlN, Al atoms in the sapphire diffuse into the upper AlN during the annealing to fill the VAl, resulting in the O-terminated sapphire, leading to the N-polar AlN. Meanwhile, O atoms in the sapphire also diffuse into the upper AlN during the annealing, forming an AlxOyNz layer and causing the inversion from N- to Al-polarity. The inversion has insignificant impacts on the quality and stress distribution of the upper AlN. Besides, this study predicts the presence of a two-dimensional electron gas at the inversion interface. However, the measured electron concentration is much lower than that predicted, which may be due to the defect compensation, low polarization level, and strong impurity scattering. The polarity inversion in high-temperature annealed c-oriented AlN/sapphire is originated from the diffusion of the Al and O atoms from the sapphire.
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影响因子：
3.7
作者：
Kresse, G;Furthmuller, J
通讯作者：
Furthmuller, J
DOI：
10.1111/j.1151-2916.2001.tb01064.x
发表时间：
2001-11-01
影响因子：
3.9
作者：
Fang, CM;Metselaar, R;de With, G
通讯作者：
de With, G
影响因子：
4
作者：
Knauer, A.;Kolbe, T.;Weyers, M.
通讯作者：
Weyers, M.
影响因子：
4
作者：
Nam, KB;Nakarmi, ML;Jiang, HX
通讯作者：
Jiang, HX
影响因子：
3.1
作者：
Shen, Xuqiang;Matsuhata, Hirofumi;Kojima, Kazutoshi
通讯作者：
Kojima, Kazutoshi