The FEI Strata 235 dual beam Focused Ion Beam (FIB) is used for TEM sample preparation, taking advantage of the focused Ga+ ion beam for site-selective material removal and the field emission scanning electron microscope (SEM) column for imaging. The SEM can be used for chemical analysis through electron dispersive spectroscopy or combined with an electron backscatter detector for orientation imaging analysis. Pt or SiO2 can be deposited for sample protection before thinning or for lift-out procedures with an Omniprobe system.
Capabilities of the NCEM FIB
Imaging: Secondary electrons or ions produced by the incoming electron or Ga+ beams are collected to form an image of the sample.
Milling/Etching: The FIB can locally etch the sample surface with submicron precision. Many variables and material properties affect the sputtering rate of a sample. These include beam current, sample density, sample atomic mass, and incoming ion mass. The main ion species used at NCEM is Ga+, with an additional low-energy Ar+ ion source available on the FIB or using the Fischionne NanoMill after FIB preparation. Additionally, iodine gas-assisted etching is available. When a gas is introduced near the surface of the sample during milling, the sputtering yield can increase depending on the chemistry between the gas and the sample. This results in less redeposition and more efficient milling.
Deposition: Conductive or insulator material can also be deposited with the aid of a gas in close proximity to the sample surface. Our system is equiped to deposit either metal (Pt) or insulator (SiO2). These materials can be deposited with either the ion or electron beam.
Microchemical analysis: Element mapping and energy dispersive X-ray spectrometry (EDS) are available on the NCEM FIB system.
Orientation imaging: Advanced diffraction and crystallographic analysis capabilities, based on electron backscatter diffraction (EBSD), are an integral part of our FIB system.
Nanoscale Manipulation: Capable of nanoscale manipulation of TEM membranes or other samples with an Omniprobe micromanipulators.
Specifications
| Ion column | Electron column | |
| Accel. voltage | 10-30 kV | 0.2 – 30 kV |
| Resolution | 7 nm | 3 nm |
