Gas Injection System

All TESCAN FIB-SEM system can be equipped with a gas injection system (GIS) which is an essential component for most of all FIB applications.
It delivers the gas chemistry needed for depositing Pt, W and C protective layers for cross-sectioning and lamellae preparation, Pt, W and SiO2 depositions for circuit edit, XeF2 for enhanced milling rates in Si. It also makes gas-assisted IC delayering possible.  In addition, GIS can deliver precursor gases to enhance and optimise milling applications in some materials or make selective etching possible.
 

Highlights

  • Deposition of protecting layers for reducing charging effects during FIB milling in cross-sectioning and TEM lamellae preparation: W, Pt, C, SiOX
  • Speeding up milling process: XeF2 for enhancing milling of Si, and H2O for enhancing milling of carbon-containing materials
  • Reduction of curtaining artifacts in some materials
  • Nano-patterning and complementing lithographic techniques
  • Enhanced or selective etching for milling multi-layer samples: Si, SiO2, Si3N4
  • Top-down perpendicular delayering in state-of-the-art chips is another important application that results from the combination of Xe plasma FIB and gas-assisted etching.

All TESCAN FIB-SEM systems can be equipped with one of the following GIS options:
  • 5-line GIS: 5 independent gases
  • MonoGIS: single gas.

 
Gas Injection System
Pt deposition on a BGA device for cross-sectioning

Related Application Notes

XeF2 injection for Ultrafast Large-area Polishing Using Xe Plasma FIB
TESCAN FERA3 is a Focused Ion Beam –Scanning Electron Microscope (FIB-SEM) with a fully integrated xenon plasma ion source. The Xe plasma ion source enables high current ion beams which on one hand, allows for extremely high milling rates - ideal for removing large volumes of material. This is a valuable quality for many technological applications in different areas such as the semiconductor industry. On the other hand, milling at high current ion beams can cause in some cases surface artifacts. One method for dealing with this situation is to use an optimised FIB scanning strategy in combination with the novel TESCAN Rocking Stage. The Rocking stage allows for tilting the sample during the milling process so that the direction of the ion beam can be changed, a strategy which has been proven to be effective for reducing curtaining effects on the milled surfaces. Alternatively, another promising way for removing surface artifacs has been found. It consists of injecting xenon difluoride (XeF2) precursor –by using a Gas Injection System (GIS) - during the FIB polishing process. The goal of this application note is to present and discuss the results of the application of this technique on different materials.
pdf – 1.6 MB