Impact of electron irradiation on electron holographic potentiometry
Impact of electron irradiation on electron holographic potentiometry
复制标题
DOI：
10.1063/1.4894718
复制
发表时间：
2014-09
影响因子：
4
通讯作者：
J. Park;T. Niermann;D. Berger;A. Knauer;I. Koslow;M. Weyers;M. Kneissl;M. Lehmann
中科院分区：
文献类型：
--
作者：
J. Park;T. Niermann;D. Berger;A. Knauer;I. Koslow;M. Weyers;M. Kneissl;M. Lehmann
虽然透射电子显微镜中的电子全息术提供了测量半导体静电势的可能性，但已知这些测量低估了电势的绝对值，特别是在GaN中。我们已经改变了几个数量级的电子辐照的剂量率，并观察到强烈的变化的全息检测到的电压。总的来说，结果表明，电子束产生的电流内的标本主要是由光伏效应和由于二次电子发射。这些电流必须被考虑用于电子全息测量的定量解释，因为它们的疏忽导致了GaN中测量的和预期的电势值之间观察到的差异的大部分。
While electron holography in the transmission electron microscope offers the possibility to measure maps of the electrostatic potential of semiconductors down to nanometer dimensions, these measurements are known to underestimate the absolute value of the potential, especially in GaN. We have varied the dose rates of electron irradiation over several orders of magnitude and observed strong variations of the holographically detected voltages. Overall, the results indicate that the electron beam generates electrical currents within the specimens primarily by the photovoltaic effect and due to secondary electron emission. These currents have to be considered for a quantitative interpretation of electron holographic measurements, as their negligence contributes to large parts in the observed discrepancy between the measured and expected potential values in GaN.