Abstract

The phenomenon of self-organized change in the composition of epitaxial layers of the Al_xGa_1 ‒ xN solid solution during their growth by chloride-hydride epitaxy on SiC/Si(111) hybrid substrates is discovered using spectral ellipsometry, Raman spectroscopy, and scanning microscopy with an X-ray spectrometer. It is found that interlayers or domains consisting of AlGaN of stoichiometric composition appear during the growth of Al_xGa_1 – xN layers with a low (about 11–24%) content of Al. A qualitative model is proposed, according to which self-organization in composition occurs due to the effect of two processes on the growth kinetics of the Al_xGa_1 – xN film. The first process is associated with the competition of two chemical reactions proceeding at different rates. One of these reactions is the formation of AlN; the second reaction is the formation of GaN. The second process, closely related to the first one, is the appearance of elastic compressive and tensile stresses during the growth of Al_xGa_1 – xN films on SiC/Si(111). Both processes influence each other, which leads to a complex pattern of aperiodic variation of the composition over the thickness of the film layer.

中文翻译：

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SiC / Si杂化衬底上生长的Al x Ga 1-x N薄膜组成的自组织

摘要

利用光谱椭偏法，拉曼光谱法发现了Al _x Ga _{1 ‒  x} N固溶体在SiC / Si（111）杂化衬底上通过氯化氢外延生长过程中外延层组成的自组织变化现象。和使用X射线光谱仪的扫描显微镜。发现在具有少量Al（约11–24％）的Al _x Ga _{1-  x} N层的生长过程中会出现由化学计量组成的AlGaN构成的中间层或畴。提出了一个定性模型，根据该模型，由于两个过程对Al _x Ga _{1 –  x}的生长动力学的影响，组成发生了自组织​​。N片。第一个过程与以不同速率进行的两个化学反应的竞争有关。这些反应之一是AlN的形成。第二个反应是GaN的形成。与第一个过程密切相关的第二个过程是在SiC / Si（111）上生长Al _x Ga _{1-  x} N膜时出现弹性压缩应力和拉伸应力。这两个过程相互影响，这导致在膜层的厚度上成分的非周期性变化的复杂模式。