Intentional polarity conversion of AlN epitaxial layers by oxygen.
Intentional polarity conversion of AlN epitaxial layers by oxygen.
复制标题
DOI：
10.1038/s41598-018-32489-w
复制
发表时间：
2018-09-20
影响因子：
4.6
通讯作者：
Albrecht M
中科院分区：
文献类型：
--
作者：
Stolyarchuk N;Markurt T;Courville A;March K;Zúñiga-Pérez J;Vennéguès P;Albrecht M
氮化物材料（AlN、GaN、InN及其合金）常用于光电子、大功率和高频电子。极性是这些材料的基本特征：当沿沿着c方向生长时，薄膜可能呈现N极性或金属极性表面，这强烈影响其物理性质。在生长期间操纵极性的可能性允许在氮化物薄膜和纳米线中建立用于现有应用的独特极性，但也为器件应用开辟了新的机会，例如，在非线性光学中。在这项工作中，我们表明，氮化铝膜的极性可以故意通过施加氧等离子体反转。我们退火的初始混合极性的AlN膜，生长在蓝宝石衬底上的金属有机气相外延（MOVPE），与氧等离子体在分子束外延（MBE）室，然后，回到MOVPE，我们存款200 nm厚的AlN膜上的氧处理的表面上。通过高分辨率探针校正扫描透射电子显微镜（STEM）成像和电子能量损失谱（EELS）分析证明了N-极性域向金属极性的切换。极性反转是介导通过形成一个薄的AlxOyNz层的表面上的初始混合极性膜，诱导的氧退火。
Nitride materials (AlN, GaN, InN and their alloys) are commonly used in optoelectronics, high-power and high-frequency electronics. Polarity is the essential characteristic of these materials: when grown along c-direction, the films may exhibit either N- or metal-polar surface, which strongly influences their physical properties. The possibility to manipulate the polarity during growth allows to establish unique polarity in nitride thin films and nanowires for existing applications but also opens up new opportunities for device applications, e.g., in non-linear optics. In this work, we show that the polarity of an AlN film can intentionally be inverted by applying an oxygen plasma. We anneal an initially mixed-polar AlN film, grown on sapphire substrate by metal-organic vapor phase epitaxy (MOVPE), with an oxygen plasma in a molecular beam epitaxy (MBE) chamber; then, back in MOVPE, we deposit a 200 nm thick AlN film on top of the oxygen-treated surface. Analysis by high-resolution probe-corrected scanning transmission electron microscopy (STEM) imaging and electron energy-loss spectroscopy (EELS) evidences a switch of the N-polar domains to metal polarity. The polarity inversion is mediated through the formation of a thin AlxOyNz layer on the surface of the initial mixed polar film, induced by the oxygen annealing.
登录
查看更多内容
影响因子：
3.2
作者：
Coulon, P. M.;Mexis, M.;Zuniga-Perez, J.
通讯作者：
Zuniga-Perez, J.
影响因子：
8.6
作者：
Neugebauer, J;Zywietz, TK;Feenstra, RM
通讯作者：
Feenstra, RM
影响因子：
4
作者：
Romano, LT;Northrup, JE;OKeefe, MA
通讯作者：
OKeefe, MA
影响因子：
0.5
作者：
Asaka, Toru;Kudo, Tatsunari;Fukuda, Koichiro
通讯作者：
Fukuda, Koichiro
影响因子：
4
作者：
Chowdhury, A;Ng, HM;Weimann, NG
通讯作者：
Weimann, NG