Standard Operating Procedure

Date Revised: 06/07/2012

Author Name: Marlon Bacungan

Scanning Electron MicroscopeLeica Stereoscan 430

Description:

A scanning electron microscope (SEM) is a characterization device that uses a beam of electrons is to scan the surface of a sample in a rastering pattern to produce high resolution images. Secondary electrons are used to characterize sample topography, back-scattered electrons gives compositional image contrast (larger atoms appear brighter than smaller ones). The electron beam also can excite the sample causing it to emit X-rays which are detected if the SEM is fitted with an energy-dispersive X-ray spectroscope (EDS or EDX).

Adjustment Knobs

Screenshot in Operation

Note-Press the left mouse button while sliding the mouse either left or right to adjust the left parameter. -Press the center mouse button while sliding the mouse either left or right to adjust the right parameter.-Press the left mouse button to open various pop-up menus, they vary depending on which icon has been selected, the mode it is in, and so on.

Procedure

Adjusting the Stage1) First click the Run Up icon . This will set it to the following starting parameters:

Magnification: 35 X Focus: 25 mmWD: 25 mm Beam Current: 400 uAEHT: 20.00 kV I Probe: 200 pAFil I: 2.34 A

2) The image should appear on the monitor.3) Use the stage rotation knob on the exterior of the device to move the chosen sample into view.4) Adjust the X, Y and Z knobs until the section of the sample you wish to image comes into view.

Acquiring an Image

1) Click the Brightness and Contrast icon to adjust the brightness and contrast levels until the image appears relatively “grey”.

2) Click the magnification/focus icon to adjust the magnification and objective lens focus (C3 Lens). Note that the focus must be increased in order to increase the magnification.

3) Click on the probe icon to adjust the kV (EHT) and probe current. Increasing the probe current reduces noise but lowers resolution at higher magnifications. An accelerating voltage of 20kV and a probe current of 200pA a suitable for any sample type.

4) Click on the filament current icon to adjust the filament current to brighten or darken the image. It can be set to the first or second peak. The first peak increases filament life but has lower resolution than the second.

5) Repeat any of the previous step to acquire an acceptable image.

Exporting an image

1) Click on Image on toolbar, then select Freeze.2) Once frozen, the image can be save clicking File on the toolbar, then select Export/Photo, then

press OK.3) It will ask if you would like to replace the previously saved image, select No. 4) Rename the image, then click OK.

Image Source: http://en-dep.web.cern.ch/en-dep/Groups/MME/MM/SEM.htm