Gas injection system (GIS)

A gas injection system (GIS) is a device option that allows deposition and etching processes to be performed on a sample. A distinction is made between FIB deposition (Focused Ion Beam Induced Deposition, FIBID), SEM deposition (Focused Electron Beam Induced Deposition, FEBID) and FIB etching.

Gas injection systems can be designed as a single GIS or as a multi-GIS. The difference is that the single GIS works with only one gas (precursor) and is terminated with only one nozzle. A multi-GIS has several nozzles (usually 5) at the end of a wide lance and can therefore use five different gases.

Commonly used gases are xenon difluoride (XeF2, often used for FIB etching), platinum (Pt, used for TEM lamellae), silicon dioxide (SiO2), iodine (I), tungsten (W), carbon (C) and water (H2O).