Numéro
J. Phys. Colloques
Volume 50, Numéro C8, Novembre 1989
36th International Field Emission Symposium
Page(s) C8-165 - C8-169
DOI https://doi.org/10.1051/jphyscol:1989829
36th International Field Emission Symposium

J. Phys. Colloques 50 (1989) C8-165-C8-169

DOI: 10.1051/jphyscol:1989829

EMISSION CHARACTERISTICS OF LIQUID METAL ION SOURCE

H. ARIMOTO1 et M. KOMURO2

1  Fujitsu Laboratories Ltd., 10-1 Morinosato-Wakamiya, Atsugi 243-01, Japan
2  Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba 305, Japan


Abstract
Energy distributions of Au-Si-Be, Au-Si, Pd-Ni-Si-Be-B, and Pt-Si liquid metal alloy ion sources were investigated, being focused on behaviors of Si++ and Si+. We found that the energy spreads of the Si++ and Si+ were kept constant at 6 to 7.5 eV, even at an extremely low emission current (50 nA). This saturation results in a decrease in the figure of merit, (dI/dΩ)/ (ƊE)2, for an ion probe forming. (dI/dΩ : angular current density, ƊE : energy spread) The energy distribution profiles suggest plural ion formation mechanisms such as field evaporation, free space field ionization, and charge transfer collision for singly charged ions. We first observed subsidiary shoulders in the Si++ energy distribution curves which cause an expansion of energy spread. This suggests two mechanisms for the Si++ ion formation such as field evaporation and postionization to doubly charged state.