Influence of surface topography on the secondary electron yield of clean copper samples

Xiao-Chuan Hu; Meng Cao; Wan-Zhao Cui

doi:10.1016/j.micron.2016.08.008

Influence of surface topography on the secondary electron yield of clean copper samples

Micron. 2016 Nov:90:71-77. doi: 10.1016/j.micron.2016.08.008. Epub 2016 Aug 24.

Authors

Xiao-Chuan Hu¹, Meng Cao², Wan-Zhao Cui³

Affiliations

¹ Department of Electronic Science and Technology, Chang'an University, Xi'an 710064, People's Republic of China; Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Department of Electronic Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China. Electronic address: huxc@chd.edu.cn.
² Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Department of Electronic Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
³ Science and Technology on Space Microwave Laboratory, China Academy of Space Technology, Xi'an, People's Republic of China.

PMID: 27595904
DOI: 10.1016/j.micron.2016.08.008

Abstract

Secondary electron yield (SEY) due to electron impact depends strongly on surface topography. The SEY of copper samples after Ar-ion bombardment is measured in situ in a multifunctional ultrahigh vacuum system. Increasing the ion energy or duration of ion bombardment can even enlarge the SEY, though it is relatively low under moderate bombardment intensity. The results obtained with scanning electron microscopy and atomic force microscopy images demonstrate that many valley structures of original sample surfaces can be smoothed due to ion bombardment, but more hill structures are generated with stronger bombardment intensity. With increasing the surface roughness in the observed range, the maximum SEY decreases from 1.2 to 1.07 at a surface characterized by valleys, while it again increases to 1.33 at a surface spread with hills. This phenomenon indicates that hill and valley structures are respectively effective in increasing and decreasing the SEY. These obtained results thus provide a comprehensive insight into the surface topography influence on the secondary electron emission characteristics in scanning electron microscopy.

Keywords: Ar-ion bombardment; Copper sample; Electron impact; Secondary electron yield; Surface topography.