Ion beam charcteristics of liquid metal ion source with a suppressor for the focused ion beam system

The liquid metal ion sources in focused ion beam (FIB) system have many advantages of high current density, high brightness and low ion energy spread. FIB system have been used widely for surface analysis, modification of integrated circuit, repair and failure analysis, etc. The energy spread characteristics have a direct influence on the chromatic aberration. It is very important to investigate the influence of suppressor on the energy spread and angular distributions for the convergence of focused ion beam. We have investigated the energy spread by using a retarding potential analyzer and angular distribution by using a Faraday cup in liquid metal ion source (LMIS) with suppressor and without suppressor, respectively. It has been shown that the energy spread and angular distributions have been drastically reduced by the suppresor in the LMIS in this experiment, which results in well focusing characteristics in FIB.