Is the Ne operation of the helium ion microscope suitable for electron backscatter diffraction sample preparation?

Beilstein Journal of Nanotechnology

article

Annalena Wolff¹ 

[1] Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology

关键词: electron backscatter diffraction (EBSD);    Ga;    helium ion microscope(HIM);    ion polishing;    Ne;   

DOI  :  10.3762/bjnano.12.73

学科分类：环境监测和分析

来源: Beilstein - Institut zur Foerderung der Chemischen Wissenschaften

【 摘 要 】

Electron backscatter diffraction (EBSD) is a powerful characterization technique which allows the study of microstructure, grainsize, and orientation as well as strain of a crystallographic sample. In addition, the technique can be used for phase analysis. A mirror-flat sample surface is required for this analysis technique and different polishing approaches have been used over the years. Acommonly used approach is the focused ion beam (FIB) polishing. Unfortunately, artefacts that can be easily induced by Ga FIBpolishing approaches are seldom published. This work aims to provide a better understanding of the underlying causes for artefactformation and to assess if the helium ion microscope is better suited to achieve the required mirror-flat sample surface when operating the ion source with Ne instead of He. Copper was chosen as a test material and polished using Ga and Ne ions with differention energies as well as incident angles. The results show that crystal structure alterations and, in some instances, phase transformation of Cu to Cu3Ga occurred when polishing with Ga ions. Polishing with high-energy Ne ions at a glancing angle maintains thecrystal structure and significantly improves indexing in EBSD measurements. By milling down to a depth equaling the depth of theinteraction volume, a steady-state condition of ion impurity concentration and number of induced defects is reached. The EBSDmeasurements and Monte Carlo simulations indicate that when this steady-state condition is reached more quickly, which can beachieved using high-energy Ne ions at a glancing incidence, then the overall damage to the specimen is reduced.

【 授权许可】

CC BY