The present disclosure relates to a gas field ion source having a gun housing, an electrically conductive gun can base attached to the gun housing, an inner tube mounted to the gun can base, the inner tube being made of an electrically isolating ceramic, an electrically conductive tip attached to the inner tube, an outer tube mounted to the gun can base, the outer tube being made of an electrically isolating ceramic, and an extractor electrode attached to the outer tube. The extractor electrode can have an opening for the passage of ions generated in proximity to the electrically conductive tip.

An improved system and method for circuit edit or repair within multilayer structures comprising a large number of layers including layers with thicknesses of 20 nanometers or even less, for example less than 10 nanometers or 8 nanometers, are capable of an advanced end-pointing of a milling operation within the large number of layers, including of end-pointing of the thin layers without unnecessarily damaging the multilayer structure.

A gas ion gun includes an anode electrode to remove electrons from a gas in order to create gas ions. The anode electrode includes a wire made of an electrical conductive material or of a semiconductor material, the wire extending along a longitudinal axis from a proximal end to a flattened distal end. The anode electrode further includes a crystal particle directly deposited on the flattened distal end, the electrical conductivity of the crystal particle being ten times smaller than the electrical conductivity of the wire.