Application of XPS time-dependent measurement to the analysis of charge trapping phenomena in HfAlOx films
Application of XPS time-dependent measurement to the analysis of charge trapping phenomena in HfAlOx films
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DOI：
10.1016/j.apsusc.2004.06.094
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发表时间：
2004-10
影响因子：
6.7
通讯作者：
K. Hirose;M. Yamawaki;K. Torii;T. Kawahara;S. Kawashiri;T. Hattori
中科院分区：
文献类型：
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作者：
K. Hirose;M. Yamawaki;K. Torii;T. Kawahara;S. Kawashiri;T. Hattori
我们发现，在X射线辐照下，Si衬底上覆盖3nm厚HfAlOx薄膜后，Si 2p光电子峰值结合能增加到一个饱和值。这种向更高的结合能的转变表明在膜中的正电荷的量的增加，和空穴陷阱的密度估计是显着高于在SiO2膜。在X射线辐照前，界面费米能级与Si衬底的价带最大值重合，表明Si表面能带向上弯曲。这意味着在X射线照射之前，薄膜中已经存在负电荷。调查的HfAlOxfilm下面的中间层对这些被困的电荷的影响表明，所观察到的空穴捕获和初始电子捕获的HfAlOxfilm是固有的。
We found that the Si 2p photoelectron peak binding energy of a Si substrate covered with a 3nm thick HfAlOxfilm increased to a saturation value during X-ray irradiation. This shift towards a higher binding energy indicates an increase in the amount of positive charges in the film, and the density of hole traps is estimated to be significantly higher than that in a SiO2film. Before X-ray irradiation, the interface Fermi level coincided with the valence-band maximum of the Si substrate, which indicates that the Si surface band bends upward. This means that there were negative charges already in the film before X-ray irradiation. Investigating the effects of the interlayer beneath the HfAlOxfilm on these trapped charges reveals that the observed hole trapping and initial electron trapping are intrinsic to the HfAlOxfilm.