A model for internal photoemission at high-k oxide/silicon energy barriers
A model for internal photoemission at high-k oxide/silicon energy barriers
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DOI：
10.1063/1.4754512
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发表时间：
2012-09
影响因子：
3.2
通讯作者：
O. Engström
中科院分区：
文献类型：
--
作者：
O. Engström
建立了一个模型来描述电子从硅穿过金属-氧化物-硅结构的氧化能垒的发射。光学吸收系数，专门描述电子的透射，发射越过势垒，从相应的实验量为整个吸收范围分离。这使得可以根据吸收系数和态密度来近似光产率，而不需要显式计算光跃迁的矩阵元素。利用该方法，理论发射产率曲线与实测数据吻合较好。从这项工作中得出的一个重要结论是，氧化物能垒高度的值应该从产率数据的不同特征中提取，而不是在文献中经常做的。这取代了通常用于确定势垒高度的做法，这表明是基于硅晶体的光学体特性。
A model has been developed to describe the emission of electrons from silicon across the oxide energy barrier of metal-oxide-silicon structures. An optical absorption coefficient, exclusively describing the transmission of electrons which are emitted across the barrier, is split from the corresponding experimental quantity for the entire absorption range. This makes it possible to approximate the photo yield in terms of absorption coefficients and density of states without need for explicitly calculated matrix elements of optical transitions. Using this method, theoretical emission yield curves are found in good agreement with measured data. An important conclusion from this work is that values of oxide energy barrier heights should be extracted from different features of the yield data than most often done in the literature. This replaces a commonly used practice for determining the barrier heights, which is shown to be based on optical bulk properties of the silicon crystal.