Di Russo Enrico, Blum Ivan, Houard Jonathan, Da Costa Gérald, Blavette Didier, Rigutti Lorenzo
UNIROUEN,INSA Rouen,CNRS,Groupe de Physique des Matériaux,Normandie Université,76000 Rouen,France.
Microsc Microanal. 2017 Dec;23(6):1067-1075. doi: 10.1017/S1431927617012582. Epub 2017 Nov 10.
The composition of GaAs measured by laser-assisted atom probe tomography may be inaccurate depending on the experimental conditions. In this work, we assess the role of the DC field and the impinging laser energy on such compositional bias. The DC field is found to have a major influence, while the laser energy has a weaker one within the range of parameters explored. The atomic fraction of Ga may vary from 0.55 at low-field conditions to 0.35 at high field. These results have been interpreted in terms of preferential evaporation of Ga at high field. The deficit of As is most likely explained by the formation of neutral As complexes either by direct ejection from the tip surface or upon the dissociation of large clusters. The study of multiple detection events supports this interpretation.
通过激光辅助原子探针层析成像测量的砷化镓成分可能会因实验条件而不准确。在这项工作中，我们评估了直流电场和入射激光能量对这种成分偏差的作用。结果发现，直流电场有重大影响，而在探索的参数范围内，激光能量的影响较弱。镓的原子分数可能从低场条件下的0.55变化到高场条件下的0.35。这些结果已根据高场下镓的优先蒸发进行了解释。砷的不足很可能是由于中性砷络合物的形成，其形成方式要么是从尖端表面直接喷射，要么是大团簇解离。对多次检测事件的研究支持了这一解释。
