LabAdviser/314/Microscopy 314-307/SEM/AFEG

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This section is written by DTU Nanolab internal if nothing else is stated.

AFEG 250 Analytical ESEM (FEI Quanta FEG 250)

DTU Nanolab AFEG positioned in B314 R034

The AFEG is an FEI Quanta FEG 250(Field Emission Gun) scanning electron microscope with a spatial resolution of 2 nm for the ETD detector in high vacuum at 30 keV. The microscope can operate in high vacuum and low vacuum modes at room temperature. Our AFEG is fitted with EDS and WDS detectors, which allows for analytical measurements in all the operation modes.

Process information

• Electron source
  • Field emission gun
• Accelerating voltage
  • 500 V- 30 kV
• Resolution
  • 2 nm at 30 kV (SE)
• Imaging detectors
  • Everhart-Thornley (SE/BSE)
  • Solid State BSE
  • Large Field (LVD)
  • Gaseous SE (GSED)
  • Gaseous BSE
  • Gaseous Analytical (GAD)
  • STEM
  • vCD
• Imaging modes

High and low vacuum

• Analytical capabilities
  • Energy dispersive X-rays (Oxford Instruments 50 mm2 X-Max silicon drift detector, MnKα resolution at 124 eV)
  • Wavelength Dispersive Spectrosopy

Equipment performance and process related parameters

Equipment		AFEG FEI Quanta FEG 250
Purpose	Vizualization and Microanalysis	Vizualization of surfaces (topography and Z contrast) Vizualization of projected image (BF STEM image) Energy Dispersive X-ray analysis (EDS) Wavelength Dispersive Spectrosopy (WDS)
Performance	Resolution	The resolution of AFEG depends on the sample and the operation mode!
		2 nm at 30 keV for Au on C sample with the ETD detector
Instrument specifics	Detectors	ETD- Everhart-Thornley for secondary electrons BSD- Solid state Back Scattered Detector LFD- Large Field Detector for secondary electrons GSED- Gaseous Secondary Electron Detector GBSD- Gaseous Backscattered Electron Detector GAD- Gaseous Analystical Detector STEM- right field Scanning Tramission Electron detector vCD- low voltage BSED CCD camera
	Electron source	Field Emission - Tungsten filament
	Stage (room temperature)	X, Y: 25 × 25 mm T: 0 to 60o R: 360o
	WDS	Oxford Instruments WDS
	EDS	Oxford Instruments 50 mm2 X-Max silicon drift detector, MnKα resolution at 124 eV
	Operating pressures	High vacuum (10-4 Pa), Low vacuum (10 to 200Pa)
Samples	Sample sizes	No actual limit (limitted by stage movment and detector position).
	Allowed materials	Conductors, Semiconductors,Insulators, Prepared Biological ((not pathogents!)