Design of a compact nuclear microprobe system with a liquid metal ion source

A compact nuclear microprobe system with a short acceleration column of 200 kV and a liquid metal ion source of lithium and beryllium, having a size of a conventional SEM system, has been designed and is being constructed. An ultrahigh-vacuum sample chamber with a three-axis goniometer, a toroidal analyzer and a solid state detector for channeling, MEIS, and RBS analyses is connected to the acceleration column. A minimum beam spot size of less than 50 nm with a current of 50 pA is estimated by optical property calculation for 200 keV Li+ LMIS. The beam spot size estimated is feasible with a minimum feature size of future gigabit memory ICs. (orig.)