Abstract We present a study for large defects called protrusions that form during the hetero-epitaxy of SiC on Si. We focus first on surface morphology, size, three-dimensional shape and internal structure, and second on photoluminescence and Raman features. These defects have a peculiar 3D structure similar to inverted square pyramids with a vertex close to the SiC/Si interface. The size of the square and the height of the pyramid are both related to the thickness of the epi-layer and are spatially limited by the stacking faults in the {1 1 1} planes. The inner core of the defect consists of nano crystals twinned with respect to the substrate orientation. The defects demonstrate broad peculiar emission band at about 750 nm, while the usual photoluminescence signal from band recombination is at 520 nm. The SiC/Si interface is studied in order to investigate the seed of protrusion defect formation. We found that seeds responsible for the formation of protrusions lie 10 nm above the SiC/Si interface. This indicates that protrusion forms after the carbonization process, in particular in the temperature ramp up after carbonization. Modifying the Si/C ratio and some other growth parameters in the post-carbonization process we succeed in reducing the density of protrusion to less than 10 cm−2.

中文翻译：

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Si上3C-SiC薄膜的突起减少

摘要 我们对在 Si 上的 SiC 异质外延过程中形成的称为突起的大缺陷进行了研究。我们首先关注表面形态、尺寸、三维形状和内部结构，其次关注光致发光和拉曼特征。这些缺陷具有特殊的 3D 结构，类似于倒四棱锥，其顶点靠近 SiC/Si 界面。正方形的大小和金字塔的高度都与外延层的厚度有关，并且在空间上受到 {1 1 1} 面中的堆垛层错的限制。缺陷的内核由相对于衬底方向孪晶的纳米晶体组成。这些缺陷在约 750 nm 处表现出宽阔的特殊发射带，而来自带复合的通常光致发光信号在 520 nm 处。研究 SiC/Si 界面以研究突起缺陷形成的种子。我们发现负责形成突起的种子位于 SiC/Si 界面上方 10 nm。这表明在碳化过程后形成突起，特别是在碳化后温度升高时。在后碳化过程中修改 Si/C 比和一些其他生长参数，我们成功地将突起密度降低到小于 10 cm-2。