Terraces at ohmic contact in SiC electronics: Structure and electronic states
Terraces at ohmic contact in SiC electronics: Structure and electronic states
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DOI：
10.1063/1.4729074
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发表时间：
2012-06
影响因子：
3.2
通讯作者：
Zhongchang Wang;M. Saito;S. Tsukimoto;Y. Ikuhara
中科院分区：
文献类型：
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作者：
Zhongchang Wang;M. Saito;S. Tsukimoto;Y. Ikuhara
结合透射电子显微镜与第一性原理计算，在碳化硅器件的接触的梯田的原子结构进行了研究，并桥接到它们的电子性质在原子尺度上。实验上，新形成的碳化物Ti3SiC2被证明直接结合到碳化硅的梯田区域中的外延和原子有序的方式，无论梯田的尺寸。进一步的第一性原理计算揭示了半导体层中的带隙状态和以连接和广泛分布的方式围绕台阶的大量电荷积累。费米能隙态的存在以及作为电子传导通道以允许电流流过半导体的可能性将阶地识别为碳化硅电子器件中欧姆接触的起源之一。这种结合实验和理论的研究提供了深入了解复杂的原子和电子结构的掩埋梯田，...
Combining transmission electron microscopy with first-principles calculations, atomic structures of terraces at the contacts in silicon carbide devices are investigated and bridged to their electronic properties at an atomic scale. Experimentally, newly formed carbide Ti3SiC2 is demonstrated to bond directly to silicon carbide in the terrace region in an epitaxial and atomically ordered fashion, regardless of dimension of terraces. Further first-principles calculations reveal gap states in the semiconductor layers and a substantial charge accumulation around terraces in a connected and broadly distributed manner. The presence of gap states at Fermi energy and the likelihood to serve as electron conduction channels to allow current flow over the semiconductor identify the terraces as one of the origins underlying the ohmic contact in silicon carbide electronics. Such a combined experimental and theoretical investigation provides insight into the complex atomic and electronic structures of buried terraces, ...