Guide to Choosing KNI SEMs & FIBs

• This guide will help you choose the best scanning electron microscopes (SEMs) and focused ion beam systems (FIBs) for your work. SEMs ( Nova 200, Quanta, Sirion) are ~33% cheaper per hour than FIBs ( Nova 600, ORION NanoFab); see usage rate details. Once you know how to use one microscope, it is easy to learn the others, so please request training. We want you to be efficient with your cleanroom expenses and we want to be efficient, as a group, in terms of allocating microscopy resources to the right kinds of work.
• See the “Functionality of SEMs & FIBs” table below for application specifics associated with each microscope (e.g. EDS, Probe Station, Omniprobe, etc.)
• See the KNI's Microscopy Lectures for more details on physical principles, applications, and examples

Low Magnification Imaging

If you only need to take low mag images, e.g. with a 4 μm field of view (FOV) or larger (i.e. if you're only using “Field Free Mode” aka “Normal Mode"):

1. Quanta: Optimal objective lens placement yields best field-free imaging; quick chamber pump/vent times (1-2 mins); backscattered electron detector )BSED) for best Z-contrast imaging
2. Nova 200 or Sirion: Both have an immersion lens, which means the field-free objective lens is not optimally placed for low mag imaging, though still works fine; these SEMs provide the benefit of being able to switch to immersion mode for higher resolution if/when needed
3. Nova 600 or ORION NanoFab: You're generally advised to leave FIBs for FIB-related work and/or the highest-resolution imaging; more expensive than SEMs

High Magnification Imaging

If you need to take high mag images with less than 4 μm FOV (i.e. if you're using “Immersion Mode” aka “Ultra High Resolution (UHR) Mode”):

1. Nova 200 or Sirion: High resolution but limited depth of field e.g. when tilting; Nova 200 has 3-4 min pump/vent times and Sirion has 1-2 min pump/vent times
2. ORION NanoFab: Maintains great depth of field at high resolution with He imaging; 2 min sample transfer times via load lock
3. Nova 600: Use for high-resolution imaging if also incorporating FIB (e.g. if imaging cross-sections), same pump/vent times as Nova 200 (3-4 mins)

Highest Magnification Imaging

If you need to take images with less than 2 μm FOV:

1. Nova 200: Can image as small as ~800 nm FOV – and features as small as 6 nm – with good clarity; has limited depth of field when in the Immersion Mode; is the cheapest option
2. ORION NanoFab: Can image as small as ~300 nm FOV – and features as small as 3 – with good clarity; maintains depth of field at smallest FOVs; more expensive than Nova 200
3. Nova 600: Works as well as the Nova 200 at these FOVs, but is more expensive to use because it has Ga-FIB capability
4. Sirion: Not quite as good as Nova 200 or Nova 600 at these FOVs

Gallium Focused Ion Beam Work

If you need to use Ga-FIB:

1. Nova 600: Use for cross-sections, TEM sample prep, point & shoot etching tasks, Pt dep, minor automation via scripting
2. ORION NanoFab: Use for major automation (via Raith ELPHY MultiBeam software), cross-sectioning without Pt protection layer

Lithography

If you want to perform lithography on resist or a hard mask and don't need extremely accurate stitching across write fields (for accurate stitching, use EBPGs):

1. Electron beam lithography on Quanta: As small as 15 nm features achievable at 30 kV
2. Helium ion beam lithography on ORION NanoFab: As small as 5 nm features achievable at 35 kV (best when used on very thin resist)
3. Ga-, Ne-, and He-FIB Hard Mask Lithography on ORION NanoFab: Directly pattern a hard mask (e.g. ALD Al₂O₃) that subsequently gets used as an etch mask

"Functionality of KNI SEMs & FIBs" Table

Consult this table to determine which of the KNI's SEMs and FIBs offer a particular functionality that you need