Institute of Materials Physics, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany.
Microsc Microanal. 2011 Feb;17(1):15-25. doi: 10.1017/S1431927610093888. Epub 2010 Oct 1.
As a major improvement in three-dimensional (3D) atom probe, the range of applicable material classes has recently been broadened by the establishment of laser-assisted atom probes (LA-3DAP). Meanwhile, measurements of materials of low conductivity, such as dielectrics, ceramics, and semiconductors, have widely been demonstrated. However, besides different evaporation probabilities, heterogeneous dielectric properties are expected to give rise to additional artifacts in the 3D volume reconstruction on which the method is based. In this article, these conceivable artifacts are discussed based on a numeric simulation of the field evaporation. Sample tips of layer- or precipitate-type geometry are considered. It is demonstrated that dielectric materials tend to behave similarly to metals of reduced critical evaporation field.
作为三维(3D)原子探针的一项重大改进,激光辅助原子探针(LA-3DAP)的建立最近拓宽了适用材料类别的范围。同时,已经广泛证明了对低电导率材料的测量,例如电介质、陶瓷和半导体。然而,除了不同的蒸发概率外,异质介电性能预计会在该方法所基于的 3D 体积重建中产生额外的伪影。本文基于场蒸发的数值模拟讨论了这些可以想象的伪影。考虑了层状或析出物类型几何形状的样品尖端。结果表明,电介质材料的行为类似于临界蒸发场降低的金属。