Analyses of High Leakage Currents in Al+ Implanted 4H SiC pn Diodes Caused by Threading Screw Dislocations
Analyses of High Leakage Currents in Al+ Implanted 4H SiC pn Diodes Caused by Threading Screw Dislocations
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螺纹螺位错引起的 Al 注入 4H SiC pn 二极管高漏电流分析
DOI：
10.4028/www.scientific.net/msf.645-648.913
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
K. Arai
中科院分区：
文献类型：
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作者：
T. Tsuji;T. Tawara;R. Tanuma;Y. Yonezawa;N. Iwamuro;K. Kosaka;H. Yurimoto;S. Kobayashi;H. Matsuhata;K. Fukuda;H. Okumura;K. Arai
制备了Al+注入p型外延层的pn二极管，研究了注入剂量对反向漏电流的影响。只有在Al浓度为2×10~(20)cm~(-3)的最高剂量下，90%以上的器件在最大电场为3 MV/cm时才表现出大于10~(-4)A的高泄漏电流。在这种器件中，通过发射显微镜和X射线形貌分析，几乎所有的发射点都对应于螺杆位错(TSD)。这些TSD被定义为致命缺陷，在最高剂量的情况下，估计密度为500 cm-2。由于发射的光谱与热辐射的光谱不同，这些发射被认为是由微等离子体造成的。通过二次离子质谱仪和低温光致发光分析，排除了Al原子、氮原子和DI缺陷的凝聚是发射的来源。
The authors fabricated pn diodes with Al+ implantation in p-type epitaxial layers, and investigated the influence of the implantation dose on reverse leakage currents. Only in the highest dose with the Al concentration of 2x1020cm-3, more than 90% of the devices showed high leakage currents above 10-4A at the maximum electric field of 3MV/cm. In such devices, almost all of the emissive spots corresponded to threading screw dislocations (TSDs) by the analysis of emission microscopy and X-ray topography. These TSDs were defined as killer defects with the estimated density of 500cm-2 in the case of the highest dose. The emissions were supposed to be due to microplasmas, since the spectra of the emissions were different from those of heat radiation. Condensation of Al atoms, nitrogen atoms and DI defects were excluded as the origin of the emissions by secondary ion mass spectrometry and low temperature photoluminescence analyses.