SEM Quick Start
Revision No.2
May 2014
Page 13 of 16
low and the noise reduction method should be set to line average. To
freeze a frame, open the
Scanning
tab on the
SEM Control
side-panel
and select
Freeze on = End Frame
from the first dropdown menu in the
Noise Reduction
box. A red dot indicator showing that the frame has been
frozen will appear at the bottom right of the viewing window when the
frame has been completely scanned and frozen. Once frozen, go to the
File
menu and select
Save As
. A dialogue box will open asking for the
directory and filename of the image to be saved. Images can be scanned
and stored at various resolutions (default,
1024 by 768 pixels
). To
increase or decrease the image resolution, simply change the value of the
Store resolution = X
dropdown in the
Scanning
tab. Once the image has
been exported the frame can unfrozen by selecting
Freeze on =
Command
from the first dropdown menu in the
Noise Reduction
box.
1.4
STEM Mode
Imaging in STEM mode is similar in many ways to that of SEM mode.
This section briefly outlines the important differences between the two
techniques. It is assumed that the investigator has already loaded an appropriate
stage, evacuated the vacuum chamber, and enabled EHT.
1.4.1
Stage Navigation and the STEM Detector
If the operator wishes to use the STEM detector, a STEM-
compatible stage must be used. Once the appropriate stage is loaded, it is
important to update the sample holder setting in the Stage Navigation tool
(Section 1.3.3). Setting the correct stage type will help reduce the risk of
collisions between the stage and obstacles in the vacuum chamber while
simultaneously increasing the ease in which samples can be located in the
viewing window.
The STEM detector is fixed to a mechanical arm that can either be
fully retracted or fully extended. To utilize the STEM detector, the
detector arm must be in its extended position directly below the stage.
Prior to inserting the detector arm, it is imperative to move the STEM
stage to what is called the ‘safe zone’. Moving the stage to the safe zone is
accomplished using the
Stage Points List
tool. This tool can be found in
the docking sidebar on the right-hand side of the viewing window. After