Guide to Choosing KNI SEMs & FIBs

• This guide will hep 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 details on usage rates. 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; backscattered electron detector for best Z contrast imaging
2. Nova 200 or Sirion: having an immersion lens 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: generally leave FIBs for FIB-related work and/or 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 (3-4 min pump times) or Sirion (1-2 min pump times): high resolution but limited depth of field e.g. when tilting
2. ORION NanoFab: (2 min sample transfer via load lock): maintains great depth of field at high resolution with He imaging
3. Nova 600: Use for high-resolution imaging if also incorporating FIB (e.g. imaging cross-sections), same pump time as Nova 200 (3-4 mins)

Ultra-High Magnification Imaging

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

1. Nova 200: limited depth of field, can image as small as ~800 nm FOV and is the cheapest option
2. ORION NanoFab: maintains depth of field, can image as small as ~300 nm FOV, more expensive than Nova 200
3. Sirion is not quite as good as Nova 200 at these FOVs; Nova 600 works as well as the Nova 200 at these FOVs, but is more expensive

Gallium Focused Ion Beam Work

If you need to use Ga-FIB:

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

Lithography

If you want to perform Lithography on Resist (without stitching):

1. Electron beam lithography on Quanta: As small as 15 nm features at 30 kV
2. Helium ion beam lithography on ORION NanoFab: As small as 5 nm features 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