Genesis and evolution of extended defects: The role of evolving interface instabilities in cubic SiC
Genesis and evolution of extended defects: The role of evolving interface instabilities in cubic SiC
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DOI：
10.1063/1.5132300
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发表时间：
2020-06-01
影响因子：
15
通讯作者：
La Magna, Antonino
中科院分区：
文献类型：
--
作者：
Fisicaro, Giuseppe;Bongiorno, Corrado;La Magna, Antonino
新兴的宽禁带半导体器件，如那些用碳化硅制造的器件，具有更快的开关速度、更低的损耗和更高的阻断电压，从而有可能给电力电子行业带来革命性的变化，这些都优于标准的硅基器件。目前的外延技术使六方晶型的碳化硅(4H-碳化硅)相对于立方晶型的碳化硅(3C-碳化硅)具有更好的可控性和更少的缺陷。然而，与其对应的六方晶型相比，立方晶型具有更好的物理性能，例如更窄的带隙(2.3 eV)，可以在硅衬底上生长，降低了SiC/SiO_2界面的态密度，以及更高的沟道迁移率，这些特性非常适合将其集成到金属氧化物半导体场效应晶体管中。阻碍3C-碳化硅在电子器件中应用的最关键问题是体层和外延层中的大量缺陷。到目前为止，文献中还没有对它们的起源和进化进行了解。在这篇手稿中，我们结合从头算校准的动力学蒙特卡罗计算和透射电子显微镜表征来评估3C-SiC中扩展缺陷的演化。我们的研究准确地指出了导致扩展缺陷产生和演化的原子机制，并确定了反相界是其他扩展缺陷的关键来源，例如具有不同对称性和序列的单层错。这篇论文表明，最终减少这些反相边界对于获得高质量的晶体特别重要，然后可以将其整合到电子设备中。
Emerging wide bandgap semiconductor devices such as the ones built with SiC have the potential to revolutionize the power electronics industry through faster switching speeds, lower losses, and higher blocking voltages, which are superior to standard silicon-based devices. The current epitaxial technology enables more controllable and less defective large area substrate growth for the hexagonal polymorph of SiC (4H-SiC) with respect to the cubic counterpart (3C-SiC). However, the cubic polymorph exhibits superior physical properties in comparison to its hexagonal counterpart, such as a narrower bandgap (2.3 eV), possibility to be grown on a silicon substrate, a reduced density of states at the SiC/SiO2 interface, and a higher channel mobility, characteristics that are ideal for its incorporation in metal oxide semiconductor field effect transistors. The most critical issue that hinders the use of 3C-SiC for electronic devices is the high number of defects in bulk and epilayers, respectively. Their origin and evolution are not understood in the literature to date. In this manuscript, we combine ab initio calibrated Kinetic Monte Carlo calculations with transmission electron microscopy characterization to evaluate the evolution of extended defects in 3C-SiC. Our study pinpoints the atomistic mechanisms responsible for extended defect generation and evolution, and establishes that the antiphase boundary is the critical source of other extended defects such as single stacking faults with different symmetries and sequences. This paper showcases that the eventual reduction of these antiphase boundaries is particularly important to achieve good quality crystals, which can then be incorporated in electronic devices.