Antistatic Technique for Suppressing Charging in Focused Ion Beam Systems Using Microprobing and Ion-Beam-Assisted Deposition

Abstract

We have developed a novel antistatic technique for suppressing focused ion beam (FIB)-induced charging in a combined system of an FIB and a scanning electron microscope. Microprobing and FIB-assisted carbon deposition are utilized to make a current path through which FIB-induced positive charges flow to ground. The effects of our method on charge neutralization capability were investigated by measuring parameter shifts of n-channel metal–oxide–semiconductor transistors. The results showed that our method prevents parameter shifts of transistors even for high-current (nanoampere-order) FIB irradiation. We also evaluated the upper-limit resistance of the current path formed by FIB-assisted carbon deposition to prevent charging induced by a given FIB current.