论文标题
通过多尺度方法,3C-SIC中杀手缺陷的起源和性质用于电力电子应用
Origin and nature of killer defects in 3C-SiC for power electronic applications by a multiscale atomistic approach
论文作者
论文摘要
SI上生长的3C-SIC外延显示出大量的扩展缺陷。特别是,在几个实验中观察到单个,双重和三重堆叠断层(SF)。迄今为止,缺陷的过度限制了3C-SIC/SI对电力电子设备的利用,尽管它具有多种理想性能(主要是在宽间隙,高分子分解和热特性方面),并且可能在SI技术中直接集成。在这里,我们使用一种基于经典分子动力学(MD)模拟和第一原则计算的多尺度方法来深入研究最常见的3C-SIC/SI(001)扩展缺陷的起源,性质和性质。我们的MD模拟揭示了形成部分脱位络合物的自然路径,终止了双重和三重SF。 MD结果被用作出色DFT计算的输入,使我们能够更好地确定核心结构并研究电子特性。事实证明,部分位错配合物终止双重和三重SF是为了引入电子状态,从而显着填补了空白。另一方面,单个部分位错终止单个SF,仅诱导非常接近间隙边缘的状态。我们得出的结论是,部分脱位复合物,尤其是最丰富的三重构件,是杀手级缺陷,在偏爱泄漏电流方面。讨论了来自设计降低其发生策略的理论/模拟的建议。
3C-SiC epitaxially grown on Si displays a large wealth of extended defects. In particular, single, double and triple stacking faults (SFs) are observed in several experiments to coexist. Overabundance of defects has so far limited the exploitation of 3C-SiC/Si for power electronics, in spite of its several ideal properties (mainly in terms of wide gap, high breakdown fields and thermal properties) and the possibility of a direct integration in the Si technology. Here we use a multiscale approach, based on both classical molecular dynamics (MD) simulations and first-principle calculations, to investigate in-depth the origin, nature and properties of most common 3C-SiC/Si(001) extended defects. Our MD simulations reveal a natural path for the formation of partial dislocation complexes terminating both double and triple SF's. MD results are used as input for superior DFT calculations, allowing us to better determine the core structure and to investigate electronic properties. It turns out that the partial dislocation complexes terminating double and triple SFs are responsible for the introduction of electronic states significantly filling the gap. On the other hand, individual partial dislocations terminating single SFs only induce states very close to the gap edge. We conclude that partial dislocation complexes, in particular the most abundant triple ones, are killer defects in terms of favoring leakage currents. Suggestions coming from theory/simulations for devising a strategy to lower their occurrence are discussed.