Scanning Electron Microscope
VEGA TS 5130

Technique Description

Scanning Electron Microscopy (SEM) uses a focused electron beam to scan small areas of solid samples. Secondary electrons are emitted from the sample and are collected to create an area map of the secondary emissions. Since the intensity of secondary emission is very dependent on local morphology, the area map is a magnified image of the sample. Spatial resolution is as high as 1 nanometer for some instruments, but 4 nm is typical for most. Magnification factors can exceed 500,000. Backscattered electrons (BSE) and characteristic X-rays are also generated by the scanning beam and many instruments can utilize these signals for compositional analysis of microscopically small portions of the sample.

Sample requirements:
Sample requirements vary with instrument and the analysis desired. Please speak with the technical staff members about specific sample requirement.

Energy Dispersive X-Ray Spectroscopy (EDS)

Scanning Electron Microscope is equiped with Energy Dispersive X-Ray analysis detector (EDX). EDX is a standard procedure for identifying and quantifying elemental composition of sample areas as small as a few cubic micrometers. The characteristic X-rays are produced when a material is bombarded with electrons in an electron beam instrument, such as a scanning electron microscope (SEM). Detection of these x-rays can be accomplished by an energy dispersive spectrometer, which is a solid state device that discriminates among X-ray energies.

Technique Advantages

  • rapid elemental analysis of small features
  • 2 dimensional elemental mapping
  • semi-quantitative analysis with standards
  • Non-destructive


Sample Requirements

  • any vacuum compatible solid (thin films, fibers, bulk materials)
  • highly polished mirror surface (preferred)

sem
Resolution: 3,5 nm at 30 kV and 4 mm WD
Magnification: 20x(at WD=30mm, HV=30kV, Image Size 512x512 pixels) to 500 000x
Accelerating voltage: 500 V to 30 kV
Electron Gun: Tungsten heated cathode
Probe Current: 1 pA to 2 µA
Chamber:
  • Internal Diameter: 160mm
  • Number of Ports : 7
  • Door Width: 1
Detectors:dard:
Options:
  • SE - ET type (YAG Crystal)
  • Probe Current Measurements
  • Touch Control
  • BSE - Annular scintillator type (YAG Crystal) with highsensitivity and high atomic number resolution
  • EDX - Take off angle: from 35° to 45° at WD from 10 to 25 mmdepending on diameter of the detector diameter
Specimen Stage: Type: Eucentric
Movements:
  • X = 40 mm manual
  • Y = 24 mm manual
  • Z = 27 mm manual
  • Z' = 6 mm manual
  • Tilt: -70° to +70° eucentrically
  • Rotation: 360° continuous manual
Working vacuum: 5x10-3 Pa
Pumping time after specimen 3 Minutes