Focused Ion Beam (DualBeam FIB-SEM)¶
A DualBeam FIB-SEM uses a focused gallium ion beam to mill or cross-section a chosen site on a specimen, while a coincident SEM column images that same point during the cut. The output is a site-specific section, a TEM lamella, or a 3D slice series, not a survey image of a bulk surface.
How DualBeam milling works¶
Two columns share one chamber. The SEM is a field-emission gun, specified from 200 V to 30 kV, with 1.2 nm secondary-electron resolution at 30 kV in high vacuum. The ion column is a gallium liquid-metal ion source, specified at 2–30 kV and 1 pA–65 nA, with 7 nm resolution at 30 kV at the coincident point.
The operator finds the site in the SEM, mills with the ion beam, and watches the SEM image as material is removed. Gas injectors can deposit platinum, tungsten, gold, or SiO2, or enhance the etch. The stage is a 5-axis eucentric goniometer (X/Y 50 mm, Z 25 mm, tilt −15° to +75°).
Three vacuum modes are listed: high vacuum, low vacuum (10–130 Pa), and ESEM (10–4000 Pa). Low vacuum and ESEM are why an insulator does not automatically need a coating.
When to use DualBeam¶
- A cross-section through a chosen defect, via, or interface
- A TEM lamella from a specific device site
- 3D slice-and-view of a small volume
- Gas-assisted deposition or selective etch at that site
- Imaging a non-conductive or hydrated specimen in low vacuum or ESEM while milling
What DualBeam cannot do¶
- It is not the survey SEM. Morphology and EDS of a large field belong on the JEOL JSM-IT710HR.
- It is not a blanket TEM prep of a 3 mm disk. Site-specific lift-out is the DualBeam job. Mechanical grind, dimple, and argon mill are a different path; those tools are not on the public catalogue.
- Gallium is implanted and the cut face can amorphise. A DualBeam lamella is not an unirradiated crystal.
- 7 nm ion resolution is not SEM resolution. The SEM column is 1.2 nm; the mill is coarser.
The Quanta 3D FEG at MPaCT Lab, Flagstaff, Arizona¶
The MPaCT Lab at Northern Arizona University operates an FEI Quanta 3D FEG DualBeam in Flagstaff, Arizona. The catalogue specifies 1.2 nm SEM resolution at 30 kV (SE, high vacuum), 7 nm ion resolution at 30 kV at coincidence, a Ga LMIS, high / low / ESEM vacuum, and gas chemistry for deposition and etch. The instrument is listed on the public equipment catalogue. It is open to NAU researchers, external academic users, and industry partners, on a fee-for-service basis or as a trained hands-on user.
| Specification | Value |
|---|---|
| Electron source | Field-emission gun, 200 V–30 kV |
| SEM resolution | 1.2 nm at 30 kV (SE, high vacuum); 2.9 nm at 1 kV (SE) |
| Ion source | Ga liquid-metal ion source |
| Ion resolution | 7 nm at 30 kV at the coincident point |
| Ion voltage / current | 2–30 kV; 1 pA–65 nA, 15 steps |
| Vacuum | High vacuum; low vacuum 10–130 Pa; ESEM 10–4000 Pa |
| Stage | 5-axis eucentric; X/Y 50 mm, Z 25 mm, tilt −15° to +75° |
Figures follow the equipment catalogue.
Full DualBeam specifications and booking →
Sample requirements¶
- Site. A feature you can find in the SEM. DualBeam is not a random mill of a whole coupon.
- Material. Say if it is insulating, hydrated, or beam-sensitive. That chooses vacuum mode and current.
- Protective layer. If the top surface matters, a deposited strap is part of the run, not optional.
- TEM lift-out. Say the target thickness and whether the lamella must go on the JEM-F200 in this lab.
Frequently asked questions¶
What is a DualBeam FIB-SEM?¶
A DualBeam puts a focused gallium ion beam and a scanning electron microscope in the same chamber, aimed at the same point. The ion beam mills or cross-sections a chosen site. The SEM images that site while the cut is happening. It is not a second SEM sitting next to a mill.
What is the difference between DualBeam and the JEOL SEM?¶
The JEOL JSM-IT710HR is an SEM for surface morphology and EDS. It does not mill. The Quanta 3D FEG DualBeam images and cuts. Use the JEOL when you need a survey image or composition. Use the DualBeam when you need a cross-section, a TEM lamella, or a site-specific cut.
Can the DualBeam prepare a TEM sample?¶
Yes, as a site-specific lamella. That is the listed public route for TEM lift-out on this catalog. Mechanical disk grinding, dimpling, and argon milling are a different workflow and are not listed on the public equipment catalogue.
Do I need a conductive coating?¶
Not always. The catalogue specifies high-vacuum, low-vacuum, and ESEM modes so insulators and hydrated specimens can be imaged without a coating. Milling still deposits gallium and can amorphise the cut face. Say if the surface must stay uncoated.
Why is my DualBeam cross-section smeared or redeposited?¶
Ion energy, current, and gas chemistry. High current mills fast and leaves debris. The catalogue lists gas-assisted etch and deposition (platinum, tungsten, carbon, and insulator etch) to reduce redeposition. A final low-current polish, not a longer high-current mill, is the usual fix.
Request time on this instrument¶
MPaCT Lab - Building 98E, South Engineering Lab
561 E Pine Knoll Dr, Flagstaff, AZ 86001
Phone: 928-523-2343 · Email: mpct.nano@nau.edu