Influence of Threading Dislocations on Lifetime of Gate Thermal Oxide
Influence of Threading Dislocations on Lifetime of Gate Thermal Oxide
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穿透位错对栅极热氧化物寿命的影响
DOI：
10.4028/www.scientific.net/msf.717-720.477
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
S. Onda
中科院分区：
文献类型：
--
作者：
Kensaku Yamamoto;M. Nagaya;H. Watanabe;E. Okuno;T. Yamamoto;S. Onda
栅氧化层的可靠性是实现SiC MOSFET的基本问题。许多报道称晶体缺陷缩短了栅氧化层的寿命。外延缺陷、基面位错和穿螺位错（TSD）被认为是致命缺陷。然而，由于商业SiC晶片的高TSD密度，其他种类的位错与寿命之间的确切关系尚未被揭示。另一方面，我们开发的RAF晶片具有低TSD密度，因此很容易评估其他类型的位错与寿命之间的关系。通过使用RAF晶片，在这项研究中，我们澄清了栅极氧化层的寿命和晶体缺陷之间的关系。我们制作了MOS二极管，并通过TDDB（时间相关介质击穿）测量了它们的寿命。击穿点由光电发射法确定。最后，我们用透射电子显微镜对缺陷进行了分类。作为结果，它被澄清，线程刃位错（TED）减少寿命一样，TSD，这是早期的报告说。栅极氧化物区域的寿命，其中包括TED，比磨损击穿短一个数量级。TSD是两个命令。
The reliability of gate oxides is a fundamental issue for realizing SiC MOSFETs. Many reports said that crystal defects shorten the lifetime of the gate oxide. And, epi defects, the basal plane dislocations and threading screw dislocations (TSD) are considered killer defects. However, because of the high TSD density of commercial SiC wafers, the exact relationship between other kinds of dislocations with lifetime has not been revealed. On the other hand, RAF wafers that we developed have low TSD density, so it is easy to evaluate the relationship between other kinds of dislocations and lifetime. By using RAF wafers, in this study, we clarified the relationship between the lifetime of the gate oxide and crystal defects. We fabricated MOS diodes and measured their lifetimes by TDDB (Time Dependent Dielectric Breakdown) measurement. The breakdown points were defined by the photo-emission method. Finally, we classified the defects by TEM (Transmission Electron Microscopy). As the results, it was clarified that threading edge dislocation (TED) decreases the lifetime as does TSD, which earlier reports said. The lifetime of the gate oxide area, in which a TED is included, was shorter by one order of magnitude than a wear-out breakdown. And, the TSD was two orders.