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Abstract：
Co-condensation of mixed SiGe nanoclusters and impingement of SiGe nanoclusters on a Si substrate were applied using molecular dynamics (MD) simulation in this study to mimic the fast epitaxial growth of SiGe/Si heterostructures under mesoplasma chemical vapor deposition (CVD) conditions. The condensation dynamics and properties of the SiGe nanoclusters during the simulations were investigated first, and then the impingement of transient SiGe nanoclusters on both Si smooth and trench substrate surfaces under varying conditions was studied theoretically. The results show that the mixed nanoclusters as precursors demonstrate potential for enhancing epitaxial SiGe film growth at a high growth rate, owing to their loosely bound atomic structures and high mobility on the substrate surface. By varying cluster sizes and substrate temperatures, this study also reveals that smaller clusters and higher substrate temperatures contribute to faster structural ordering and smoother surface morphologies. Furthermore, the formed layers display a consistent SiGe composition, closely aligning with nominal values, and the cluster-assisted deposition method achieves the epitaxial bridging of heterostructures during cluster impingement, highlighting its additional distinctive characteristics. The implications of this work make it clear that the mechanism of fast alloyed epitaxial film growth by cluster-assisted mesoplasma CVD is critical for extending it as a versatile platform for synthesizing various epitaxial films.
摘要：
在这项研究中，使用分子动力学（MD）模拟对混合SiGe纳米团簇的共缩合和SiGe纳米团簇在Si衬底上的撞击进行了应用，以模拟中等离子体化学气相沉积（CVD）条件下SiGe/Si异质结构的快速外延生长。首先研究了SiGe纳米团簇在模拟过程中的凝聚动力学和性质,然后从理论上研究了在不同条件下瞬态SiGe纳米团簇对Si光滑表面和沟槽衬底表面的冲击。结果表明，混合纳米团簇作为前体显示出高生长速率下增强外延SiGe薄膜生长的潜力，由于它们松散结合的原子结构和在衬底表面的高迁移率。通过改变簇大小和衬底温度，这项研究还表明，较小的簇和较高的基板温度有助于更快的结构有序和更平滑的表面形态。此外，所形成的层显示出一致的SiGe成分，与标称值紧密对齐，团簇辅助沉积方法实现了团簇撞击过程中异质结构的外延桥接，突出了它的其他独特特征。这项工作的含义清楚地表明，通过簇辅助中浆CVD进行快速合金化外延膜生长的机理对于将其扩展为合成各种外延膜的通用平台至关重要。
