硅/碳化硅和碳化硅/金刚石异质结构中的界面热传输：非晶中间层和碳化硅多型体的影响
Interfacial thermal transport in Si/SiC and SiC/diamond heterostructures: effects of amorphous interlayers and SiC polytypes
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中文总结 AI 辅助
研究通过非平衡分子动力学模拟，探讨硅/碳化硅和碳化硅/金刚石异质结构中界面热传输，发现4H-SiC的ITC高于3C-SiC，超薄aSiC层可增强热传输，厚或富硅非晶层抑制ITC，SiC/金刚石界面需尖锐无缺陷键合以利用其高导热性。
中文摘要 AI 辅助
本研究使用非平衡分子动力学模拟研究了通过硅/碳化硅和碳化硅/金刚石界面的声子介导的热传递，重点关注碳化硅多型体和非晶中间层的影响。对于尖锐界面，4H-碳化硅由于其更宽的有源声子谱和与硅更好的谱匹配，表现出比3C-碳化硅更高的界面热导率（ITC）。虽然非晶层通常会降低ITC，但一个关键观察结果是，超薄的0.5纳米非晶碳化硅（aSiC）层可以增强硅/3C-碳化硅系统中的热传输：ITC从613 MW/m^2-K（尖锐）增加到716 MW/m^2-K，显示出声子桥效应。VDOS（振动态密度）分析证实，优化的超薄aSiC层改善了振动重叠并打开了额外的声子传输通道。相比之下，较厚或富含硅的非晶层通过增强非弹性声子散射显著抑制ITC。对于碳化硅/金刚石界面，任何非晶层，特别是aSi，都会导致严重的ITC降解，突出了需要尖锐、无缺陷的键合来利用金刚石的高导热性。
英文摘要
This study examines phonon-mediated heat transfer across Si/SiC and SiC/diamond interfaces using non-equilibrium molecular dynamics simulations, emphasizing the influence of SiC polytypes and amorphous interlayers. For sharp interfaces, 4H-SiC exhibits considerably higher interfacial thermal conductance (ITC) than 3C-SiC, due to its broader active phonon spectrum and superior spectral matching with Si. While amorphous layers generally reduce ITC, a key observation is that an ultrathin 0.5-nm amorphous SiC (aSiC) layer can enhance heat transport in the Si/3C-SiC system: the ITC increases from 613 MW/m^2-K (sharp) to 716 MW/m^2-K, demonstrating a phonon-bridge effect. VDOS (vibrational density of states) analysis confirms that optimized ultrathin aSiC layers improve vibrational overlap and open additional phonon-transport channels. In contrast, thicker or silicon-rich amorphous layers significantly suppress ITC through enhanced inelastic phonon scattering. For SiC/diamond interfaces, any amorphous layer, particularly aSi, causes severe ITC degradation, highlighting the need for sharp, defect-free bonding to exploit diamond's high thermal conductivity.
