FEI (Philips) XL30 Teaching SEM with BSE mode and EDAX analysis

Prepared by:

J. Scanlon, Y. Qi and D. Golematis

Location:

Dow 2224

Hazards:

The following materials and equipment associated with this procedure present exposure or physical health hazards. Safety precautions are prudent and mandatory.

None



Controls:

Prior to performing this procedure, the following safety equipment must be accessible and ready for use: (e.g. chemical fume hood, biological safety cabinet, laminar flow hood, chemical spill kits)

None



Protective Equipment:

Prior to performing this procedure, the following personal protective equipment must be obtained and ready for use: (e.g. acid resistant gloves, safety eyewear, lab coat, chemical splash apron)

None needed, though you should wear gloves when handling specimens or touching the SEM itself to prevent contamination.



Waste Disposal:

This procedure will result in the follow regulated waste which must be disposed of in compliance with environmental regulations.

None



Spill:

In the event that a hazardous material spills during this procedure, be prepared to execute the emergency procedure below.

Not Applicable


Instructions:


http://www.emal.engin.umich.edu/courses/courses.htmlContact Ying Qi or Justin Scanlon for training. For booking go here. You will need an MSE user account. Please fill out the form in the attachments and bring the original copy when you come for your training. Fill out the usersection and have your advisor fill out the section provided. An account shortcode and account contact will be required as well. ALL TRAINING MUST BE GIVEN BY MSE TECH STAFF.

See new SOP linked above.

OLD SEM SOP:


 

outside sem

 

 

stage 1 stage 2

 

Quick reference guide for the Scanning Electron Microscope (SEM)

 

A. Before obtaining an initial image, review the toolbar, icons and menu system 

1. SEM icon row:

  • Appears at the top of software
  • Show or hide by pressing SHIFT-F1

Icons Complete

2. Function row shortcuts:
  • Located just above databar
  • Repeats tasks of icon row
  • Show or hidge by pressing F1
  • Activate by pressing the corresponding function key or clicking on top of the phrase:
null

3. Breakdown of icons:



Print
vscope
Use videoscope to help manually adjust
contrast & brightness.
Databar
Adjust information about the settings
shown on the image.
Measurement
Use for measurements in X & Y
directions.
Scanning Modes:

slowscan tv mode
Change between a high and low resolution
scan.
Selected Area
Go between scanning a small region and
the entire screen.
Freeze Image
Freeze image at current scanning position 
(will appear yellow) or unfreeze to 
continue scanning.

Auto Functions:

It is strongly encouraged not to  rely upon
these features. Use the manual 
adjustments for optimal imaging.

AutoCombi
Auto corrects the contrast and brightness.
Autofocus
Auto correct the focus.
Autostig
Auto corrects the stigmation of the SEM.

Stage Movement:

Off Mode
Get Mode
Shift mode
Track Mode
When to use each:
  • Use Off mode when movement is
    not desired
  • Use Get mode when placement 
    near the center is desired
  • Use Shift mode when very slight 
    adjustment in position are at very 
    high magnifications
  • Use Track mode most of the time

Control Area:

Settings
Starting screen, contains Pump & Vent 
buttons as well as voltage adjustments.
Imaging
Commonly used for adjustments with
magnification, scan rotation and stigmation.
Image Map
Adjustments
Should only be used by MSE tech staff and
SEM service person.
Stage+
Used for X, Y and Z adjustments.

 

 

B. Specimen preparation for SEM:

Conductive specimens that are in a
metallagraphic mount:

  • Common materials include black
    phenolic powder (bakelite) and 
    epoxy.
  • Some can be conductive by 
    containing carbon.
  • Make a connection from the 
    sample to the aluminum stub 

    Aluminum Stubs
  • Can use double sided graphite 
    tape, copper tape or graphite paste 

    Copper Tape and Graphite Paste
Free standing conductive samples:
  • Need to make a connection with
    the sample to the aluminum stub
  • Can use double sided graphite or 
    copper tape or graphite tabs 

    Copper Tape and Graphite Paste
Conductive specimens that are in a free
standing or mounted *non-conductive
samples:

  • Attach specimens following step 2, 
    above, and place in Hummer VI sputter
    coater and carbon coater
  • Can coat with either Au/Pd or carbon
  • Follow procedure for sputter coater 
    and carbon coater
*If looking at the edge of a mounted
specimen lightly coating it might help to
eliminate image distortion and charge 
buildup in the nonconductive mounting
material

Examples of prepared samples:

bakelite mounted sample

free standing sample



C. Installing a specimen into the SEM:

1. Vent the chamber
  • Confirm venting

  • After approximately 1 minute, try to pull door 
    open. If door opens, press vent button again
    to turn off venting. 



  • This will reduce the required
    amount of dry nitrogen gas consumed in the
    venting process.
2. Place specimen on stage
  • Make certain aluminum stub is flush to the 
    stage.
  • Fasten sample using provided Allen wrench 

    stage

  • Using stainless steel height gauge, adjust 
    height to be 5mm or greater,
    • Samples optimally should be 
      at 10mm distance from 
      final lens

    • Should be adjusted more accurately in the
      software
3. If using BSE detector:
  • Make certain to place the backscatter detector 
    onto the bottom of the final lens
  • If performing EDS analysis as well, the BSE 
    detector must be removed before beginning 
    EDS detection as it blocks the X-RAYS from 
    going to the EDAX 

    BSE detector
4. Pumping the chamber:
  • Close door with light pressure
  • Click on the "PUMP" button to initiate vacuum procedure
  • Takes usually between 2 and 5 minutes to vacuum the chamber
  • There are 3 messages that will be noticed:
    • pumping
    • pre-vac
    • vac OK




D. Making an image of the specimen:
1. Magnification Adjustment:

1. Drop-down menu of presets.
mag_pull_down

Can be changed by clicking "Change..."
change mag

Say "Ok" and go back to the drop down menu 
and adjusting.
2. Control Area Imaging: Magnification "slider" 
magnification slider

  • The gray middle bar slides the magnification up and down.
  • If you press the gray arrows it increments by the smallest amount
  • If you click on the space between the arrow and the slider, it moves 
    by the largest increments.
  • The increment depends on the magnification you are working with


3. Stage Track Mode
  • If you place the cursor in very center of the circles of the control 
    window and move them slightly up or down, you will notice a + 
    and - sign appear.
  • Left click to (+)increase or (-)decrease magnification.On the 
    keyboard number pad, the (+) and (-) keys doubles and halves 
    the magnification accordingly.







When to use each:

  • Use the number pad method for general alterations in magnification
  • Use the magnification slider at higher magnifications for smaller increments in magnification change
  • Use the drop-menu to attain "cleaner" looking magnification numbers or if its not possible using a different method.

2. Beam and Spotsize Adjustment:

1. Beam pull down menu: Choosing 
or creating a preset in the  (Can be 
changed by clicking "Change..." 
similarly to Magnification). Also 
contains a list of spotsize presets.


beam pull down
2. Control Area Settings: Beam

Beam Minimized

Expanding the Beam information box by 
left clicking on the square located in the
upper right corner. There is a slider for 
accelerating voltage and spotsize adjustment . 
These adjustments act in a similar manner 
to those of the magnification.

Beam Maximized

Use the slider to raise or lower the voltage
  • Press left/right arrow to change voltage by 0.1kV
  • Press in the grey area to move the voltage by 1kV

When to use each:
  • Use low voltage (less than 7kV) for:
      • Non conductive material, even if it has been coated it might still need to be low
      • Samples that have charging problems
      • Interested in gathering more surface information about sample
      • Use higher voltages (greater than 7kV) for:
        • Conductive samples
        • Interested in gathering more bulk sample information
    • Set the spot size:
      • Small spot size (1 - 4) at high magnification, non-conductive samples and samples that have charge buildup
      • Large spot size (4 - 6 or greater) for conductive materials at low magnification


3. Turn the beam on:

  • Press the voltage button
  • WARNING: For the safety of the SEM 
    chamber, the working distance (WD) must be set before continuing with setting

    [Insert image of warning box]

  • WD is the focal point of the beam, this operation ties the WD to the physical distance from the final lens (Z)
  • Make rough adjustments to the contrast/brightness, just to be able to see the sample
  • Make rough adjustments to the focus, right click and drag the mouse, to the left and to the right (notice how the WD on the data bar changes)
  • Click okay to the message
  • Adjust the Z dimension in the Stage box located in the lower right hand corner to be optimally at 10mm
  • 10mm working distance for most imaging conditions(samples cannot be closer than 5mm)
  • Can go closer but no closer than 5mm at very high magnification (<15,000X)
  • Can go to a larger working distance for fractured surfaces and samples with rough surfaces (increasing the depth of field)
  • Repeat operation as needed to get an accurate WD of 10mm
    • Can bring up the Z<_>FWD and repeat the above steps
    • Perform at slightly higher magnifications to see more features of the sample

4. Scan
  • Drop-down menu of different scanning rates:
    beam pull down
    • TV scan (fastest scan, lowest resolution) --> Slow Scan 4 (slowest scan, highest resolution)
      • Switch between TV & Slow Scan by clicking on the TV button or pressing F8
    • Full frame scans the entire screen.
    • Selected area scans a particular region.
    • When to use each:
      • Use TV scan to move around sample
      • Use Slow Scan 1 or 2 for contrast/brightness adjustments
        • Use Videoscope (F3) to help manually adjust the contrast brightness
        • Bottom and top dashed lines represent the greyscale from 0 to 255
        • In order not to lose any important data, make sure you stay between the lines
      • Use Slow Scan 3 (in selected area mode (F6) at slightly higher magnification) for final focus and astigmatism adjustments
5. Detectors
  • Drop-down menu of SE (secondary electron); BSE (backscattered electrons);  Mixed (A mixture of BSE and SE); Do not use IMG. BSE must be placed onto the final lens before use.
6. Filter
  • Drop-down menu of filters. Choose between Live, Integrate, Average, Freeze, and Stand Definition. These settings are dependent on what scan rate is currently being used.
7. In/Out
    • Drop-down menu.
    • Image: Save data to drive E: which is the C:\users located on the EDAX computer. Check options on whether to show databar on image or not.
      • DOS Commands: Create a new folder ( .\newfolder\ ); To go up a folder level (  ..  )
      • Limited to 8 characters per file or folder name.
      • Have to click save or it will attempt to restore image.
    • Databar: Choose settings for the Databar, including checked off options as acceleration voltage (Acc V.), spotsize (Spot), detector (Det), working distance (WD), exposure number (Exp), and whether to have a databar background (Background).  Display databar may be checked to show where on the image the databar will appear.
      • In the user space, more information about the specimen can be input.
      • The databar can also be accessed by double-clicking on the databar directly.
    • Videoprint! : Prints a copy of whatever is currently on the screen to the small Sony Video Graphic Printer located to the right of the SEM monitor.
    8. Stage
    • X,Y, Z stage controls can be found here to help adjust the sample position in the chamber


    9. Additional references:

    EDAX


    Manuals and videos are currently located on the EDAX computer located next to the SEM's computer. They review in detail the different tabs in the software and the settings that should be used.
    Additional references:
    From EMAL's website: "Robert Anderhalt of EDAX, Inc. has been kind enough to make his presentation notes available for EMAL users. A PDF document may be downloaded here."

    Equipment:


    Last Revision:

    Sep 29, 2020