Local Leakage Current of HfO2 Thin Films Characterized by Conducting Atomic Force Microscopy
Local Leakage Current of HfO2 Thin Films Characterized by Conducting Atomic Force Microscopy
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DOI：
10.1143/jjap.42.1949
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发表时间：
2003-04
影响因子：
1.5
通讯作者：
H. Ikeda;T. Goto;M. Sakashita;A. Sakai;S. Zaima;Y. Yasuda
中科院分区：
文献类型：
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作者：
H. Ikeda;T. Goto;M. Sakashita;A. Sakai;S. Zaima;Y. Yasuda
我们的特点是结晶度和局部漏电流的HfO 2薄膜显微镜，使用原子力显微镜和透射电子显微镜。它是澄清，泄漏路径强烈依赖于HfO 2晶体结构。在700°C沉积时，HfO 2薄膜主要为多晶柱状晶粒，薄膜上分散着堆叠的多晶晶粒。在堆叠的晶粒处的三重态点充当泄漏位点，其中电子隧穿的厚度有效地减小。此外，在室温下沉积的非晶HfO 2中，观察到施加的电压偏移，表明正电荷存在于HfO 2/Si界面处。另一方面，在500°C下沉积的HfO 2膜中，其中结晶晶粒分散在非晶结构中，没有观察到显著的导电区域。因此，结晶区和非晶区之间的边界对漏电流没有贡献。
We have characterized the crystallinity and the local leakage current of HfO2 thin films microscopically, using conducting atomic force microscopy and transmission electron microscopy. It is clarified that the leakage path depends strongly upon the HfO2 crystallographic structures. At 700°C deposition, the HfO2 film has mainly polycrystalline columnar grains and stacked polycrystalline grains are scattered on the film. A triplet point at the stacked grains acts as a leakage site, where the thickness for the electron tunneling is effectively reduced. Moreover, in amorphous HfO2 deposited at room temperature, applied voltage shift are observed, indicating that positive charges are present at the HfO2/Si interface. On the other hand, in the HfO2 film deposited at 500°C, in which crystallized grains are scattered in the amorphous structure, no significant conductive region is observed. Therefore, the boundary between crystalline and amorphous regions does not contribute to leakage current.