A new and simple probe-based method for preventing charging in focused-ion-beam micro-sampling

A charging free (FIB) micro-sampling technique was developed for high resolution sampling with insulator. This technique used a mechanical probe brought into contact with or close to a substrate while it is being irradiated by FIB (5 pA to 10 nA). The probe then emits electrons that neutralize charging of the surface of the substrate. The shunt current continuously flows through the probe if the distance between the probe tip and FIB irradiation site stays at a critical distance. When the probe tip is high above the substrate, it still emits electrons through the vacuum to the surface. It is concluded that this simple method of sampling insulators can attain sampling resolution similar to that of sampling conductive substrates.