North Campus Instruments - The Philips XL30ESEM

Applications

SEM, BSE imaging, Cryo-stage, XEDS, remote control

Accelerating Voltage

0.5 to 3.0 kV (100 V steps) 3.0 to 30 kV (1 kV st

Filament

Tungsten

Vacuum

~10^-6 torr in sample chamber

Dectectors

Imaging: Everhart-Thornley & Solid State Backscatter Detector Gaseous Secondary Electron Detector XEDS: UTW Si-Li Solid State X-ray Detector (with integrated EDAX Phoenix XEDS system) Cryo-stage by Oxford Instruments

Magnification

20 - 600,000x

SEM Resolution

2.5nm at 30kV - high vacuum 4.0nm at 30kV - 5 Torr of water vapor 6.0nm at 1k

Sample Requirements

Samples must be compatible with high vacuum, i.e. clean and dry. Samples should be handled with tweezers or gloves. A large range of sample sizes will fit into the chamber up to a limit of about 6 inches in diameter and/or ~ 2 inches tall. You may not be able to access the entire area of a very wide sample. Ask for assistance if you are approaching the limits. High Vacuum Mode Samples need to be conductive in high vacuum mode. Semi-conductors are OK. Non-conductive samples should be coated with a conductive layer. Conductive samples surrounded by a non-conducting medium should be provided with a conductive path to the SEM stub. ESEM Mode Samples may be insulating or conducting, a rounding path as close to the sample area of interest is still an excellent idea.

Joanna Mirecki Millunchick, a professor in the Department of Materials Science and Engineering, operating the Philips XL30ESEM. Scanning Electron Microscopy The Philips XL30 Environmental Scanning Electron Microscope (SEM) is one of a generation of SEMs that is completely controlled from a computer workstation. The XL series instruments are controlled by a personal computer running Microsoft Windows NT. This EMAL instrument employs a tungsten filament and is capable of functioning in both high vacuum mode and ESEM mode . This makes the instrument ideal for both imaging and microanalysis of a wide range of both electrically conducting and insulating materials. Additional Resources: SEM Class Lecture Notes by John F. Mansfield by CJW Flash Animations Zoom in and out on an SEM sample Contrast mechanisms arising from sample topography in the SEM Energy Dispersive X-ray Spectroscopy - how the x-rays are generated