title: Heating-induced variations of secondary electron emission from ion-cleaned copper samples.
abstract: Secondary electron (SE) emission due to electron impact depends strongly on surface conditions. The variations of SE yield and spectrum with the heating temperature of Ar-ion-cleaned oxygen-free copper samples are therefore measured in situ in a multifunctional ultrahigh vacuum system. The SE yield and the SE spectrum are observed to increase and to narrow, respectively, after sample heating. The maximum SE yield increases from 0.97 before heating to 1.25 after heating at ∼313 °C, and the corresponding full width at half maximum of SE spectrum decreases considerably from 9.3 to 5.5 eV. More CO2 and Ar ions are shown to desorb at a higher heating temperature by residual gas analysis, indicating their contribution to the reduction in work function and surface potential barrier. Ar-ion desorption appears to affect the SE spectrum more than the SE yield. The obtained results provide a new insight into complicated surface influences on SE emission in thermal applications of scanning electron microscopy.
authors: 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, PR China.
authors: Xiao-Chuan
authors: XC
authors: Hu
authors: 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, PR China.
authors: Hai-Bo
authors: HB
authors: Zhang
authors: 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, PR China. Electronic address: mengcao@mail.xjtu.edu.cn.
authors: Meng
authors: M
authors: Cao
authors: Science and Technology on Space Microwave Laboratory, China Academy of Space Technology (Xi'an), Xi'an 710100, PR China.
authors: Na
authors: N
authors: Zhang
authors: Science and Technology on Space Microwave Laboratory, China Academy of Space Technology (Xi'an), Xi'an 710100, PR China.
authors: Wan-Zhao
authors: WZ
authors: Cui
keywords: Ar-ion cleaning; Electron impact; Metal surface; Sample heating; Secondary electron emission; Thermal desorption