Using the Hitachi 3400-N VP-SEM Before You Begin:

Sign in on the Calendar (we are pretty strict about this). Wear gloves when handling anything that goes in the chamber such as stubs, specimens, sample holders. Finger oils contaminate the machine and destroy image quality. Measure your sample’s diameter and height accurately: Improper sample measurements will cause the sample to hit the detectors and create thousands of dollars of damage!

Opening the Chamber to Load Specimens (This may also be done later using the software)

1. Click the “AIR” button on the front of the machine (push hard enough to hear vacuum change) (Fig. 1-A):

2. Wait a few minutes until you hear the machine beep 3. Insert sample holder. **For multi-holder, insert with

sample #1 facing blue pen mark in chamber** 4. Close the chamber and hold it shut with your hand.

Press “EVAC” button on front of machine (Fig. 1-B). Let go of chamber door when vacuum engages it.

Starting PC-SEM: 5. Click the “PC-SEM” icon on the desktop. There is no

password. 6. When the PC-SEM finishes booting, you will see the

Specimen Dimensions window above (Fig. 2). Select the correct Diameter/Size and Height (Fig. 2-A) for the sample. Click OK.

7. On the right side of the screen are 4 overlapping control panels -Condition, Image, Utility and Stage (Fig. 3). The software will launch on the stage control panel as shown.

8. Check the other panels to be sure the last user left this in the modes you want to use or you’ll have difficulties and could damage your sample.

Figure 2. Specimen Size Setting

-A

Figure 3. Control Panels

EVAC AIR

-A B-

Figure 1. Front Panel Buttons

9. Go to the “Image” tab and choose SE (Secondary electron) or BSE (back scattered electron) mode as required/preferred. Standard imaging SE mode (Fig. 4-A).

10. Go to the “Condition” Tab and ensure the vacuum is set to SEM mode ond not VP-SEM (variable pressure i.e. low vacuum) (Fig. 4-B).

11. Go to the “Stage” tab (Fig. 5) and set the desired stage height (z-position) (Fig. 5-A). 10 mm is a good starting point which also works for EDAX. Use longer distance for more depth of focus on uneven samples. Use shorter for higher resolution. Click GO (Fig. 5-B).

12. Wait for specimen to reach desired height. 13. You can also use this panel to:

a. Rotate the sample (Fig. 5-C) b. Tilt the sample (Fig. 5-D) c. Move the stage by increments to find and centre your

features of interest (Fig. 5-E). 14. For Multi-Holder ONLY: If you are using the multi-

holder, click the “Memory” button (Fig. 5-F) in the lower right corner of the stage tab. This Pop-up will appear:

a. The 6 positions are programmed in the pop-up window (Fig. 6). Choose “Page 1”, then choose the desired sample position. “No.1” goes to the first sample if you took care to position the holder as described when loading your sample.

b. Click “Move” (Fig. 6-A) to go to that sample position.

c. PLEASE DO NOT click the other buttons on this panel or you may overwrite our program.

Figure 5. Stage Controls

-A -D -B

C-

E-

F- Figure 6. Stage Memory-Multi Sample

-A

A-

B-

Figure 4. Image + Condition Tabs

Electron Beam Setup:

1. Double click on the Beam Settings Frame (Fig.7-A) to open the settings window. 2. In the settings window (Fig.8), select the appropriate KV

(Fig.8-A) for your specimen. 3. Set the Probe Current (Fig.8-B) to ~50 to begin. Probe

current should be lower for very high magnifications (>20,000x). Turn it higher for EDAX or long working distances.

4. Set the Working Distance to match your stage height. This is where the beam will come to a focus (Fig.8-C).

5. Once the chamber properly evacuated and the HV warning disappears, switch ON the electron beam (Fig.8-D). Wait for the HV progress to complete (Fig.9)

6. Click the AFS button (Fig.8-E) to auto-saturate the filament so it emits a good electron flow. It should deliver an emission current above 65-70uA (Fig.8-F).

7. Choose the Mechanical Aperture (Fig.10) recommended for your sample and magnification (see us). You need a higher number (smaller, 3-4) for high magnification (above 10,000) and a low number (1—2) for very low magnification (below 2000) or EDAX.

8. Turn Magnification to 100x using button at top of screen (Fig.7-B), or using the manual dial by the keyboard. You will use this to find your specimen and start to focus.

Record Your Best Settings Here: Aperture: Kilovolts (KV) Probe Current: Stage Height/WD:

Figure 7. PC-SEM Control Buttons A B

A-

-B

C-

D-

E-

F-

Figure 8. Beam Setup Panel

Figure 10. Mechanical Aperture

Figure 9. HV Progress

Focus, Brightness and Alignment Setup:

1. Click “Freeze/Run” (Fig.11-A) to start the scan if it isn’t running. 2. Click the ABCC button (Fig.11-B) to set Auto Contrast and Brightness. This is only a

starting point. Further fine adjustment controls are on the manual dial panel. 3. Use the “Fast 1” or “Slow 1” (Fig.11-C) scan speed settings to adjust focus so

the screen refreshes quickly. Clicking on the button twice makes it change from 1 to 2 (slower) USE SLOW 1 or 2 FOR BSE-you can’t see an image on “Fast”.

4. Once you see an image, turn the mechanical aperture (Fig.10) slightly to even out the illumination across the image. If the image disappears, click ABCC again. If it turns flat grey, go back to a lower aperture and do an alignment.

Alignments must be done whenever changing the KV, probe current, or aperture size. Get our help. Refer to “Align the Instrument” (Appendix 1)

If you need to align the instrument, do it first between 2000-5000x, then repeat again at 2x desired magnification.

5. Focusing your sample is a multi-step process: a. Increase magnification on dial (Fig.12-A) slowly to desired level. If the image

moves, it isn’t properly aligned yet-repeat alignment. Adjust focus (Fig.12-B) contrast (Fig.12-C), and brightness (Fig.12-D) as needed as you magnify.

b. To sharpen the focus -start by using the fine focus (Fig 12-B) to get the best possible image. Using auto focus “AFC” (Fig.11-D) may help if you are close to the focal plane.

c. Next, use Stigmator X dial (Fig 12-E) – turn one way and then the other to find best image. Stop at the best point.

d. Now repeat this using Stigmator Y dial (Fig 12-F).

e. Adjust the fine focus again. Repeat this process 2-3 times until you get the best possible image. Unless you change the beam, stigmation is now complete. Using only fine focus should work hereafter.

Figure 12. PC-SEM Control Buttons

A B

C D

E F

Figure 11. A C B D

6. Adjust contrast and brightness for proper dynamic range

(good blacks, whites and greys). The ABCC button (Fig 13-A) is a starting point only-increase contrast and decrease brightness slightly from there using dials (Fig 12-C,D)

7. Click the desired scan speed: Fast (Fig 13-B) to scan your specimen, locate areas of interest, and focus; OR Slow3/5 (Fig 13-B) to preview a high resolution image prior to capture.

Capturing an Image: 1. You must be on Slow3/5 (Fig.13-B) scan mode before

you click the M/2560 button (Fig.13-C) to capture an image.

2. The Capturing Image progress window (Fig.14) will open and the image will gradually freeze, then the Captured Image Window will open in the lower part of the monitor as a thumbnail image (Fig.15-A).

3. The Image window will display CAPT (Fig.15-B) in the upper left corner and the image is now frozen.

4. To return to live viewing, click “Freeze/RUN” (Fig.13-D) and Fast again to reactivate the detector and move to a new spot.

Saving Images: 1. Select the thumbnails of those images you wish to save-see yellow (Fig.15-A). 2. “Embed into image” checkbox (Fig.15-C) will burn in annotations associated with

image. (To change what information is displayed on your image, go to Set-up – Image Display – Record)

3. Click the “Save” button (Fig.15-D) – this will open a dialogue box. 4. Click “Select” in the saving pop-up window to find your folder first. (You have to

hit save again after naming the file-old software!) 5. DO NOT KEEP > 10-15 images open, or the software may freeze up. Save and

then delete them. Click All (Fig.15-E) then delete All to clear the RAM.

Figure 14. Capture Progress

Figure 15. Capturing & Saving

A-

-B

-D -C

-E

Figure 13. D B A C

Changing Specimens and/or Shutdown:

1. Click the HV OFF button in the upper left (Fig 16-A) or on the beam control window (Fig 17-A).

2. Click the AIR button in the upper right (Fig 16-B). 3. The Specimen Dimensions window will open (Fig 18).

If you will be continuing, enter the dimensions of your next specimen.

4. If you are shutting down, Select Size=15mm and Height= Standard and click OK. The chamber will open in about 90 seconds. (you will see a “Processing to Air” message with stars that count down to opening)

5. Using gloves or forceps, remove your specimen. Change specimens now or leave sample holder in drawer away from dust if you are finished.

6. Close the Chamber door and click the EVAC button in the software (Fig 16-B) OR at the front of the machine (Fig 20-A).

7. When the system has fully evacuated, begin imaging again as before. You shouldn’t need to realign the machine, but you will need to re-saturate the filament if you are continuing.

8. IF YOU ARE FINISHED: quit the PC-SEM Program. 9. If you get a request to save the stage history, say “No” 10. Make sure that you sign out on the calendar. 11. Transfer your files using Dropbox NOT USB 12. Leave Computer ON and area clean

Figure 17. Beam Setup Window

A-

Figure 19. PC-SEM Shutdown

Figure 20. PC-SEM Shutdown

A-

Figure 18. PC-SEM Control Buttons

Figure 16. A B

APPENDIX 1: Align the Instrument: If you change the mechanical aperture, the accelerating voltage or the probe current, specific alignments of the instrument must be performed. Mechanical Alignment:

-At the desired magnification, first turn the X-Align knob (Fig.A1-X) at the side of the aperture control until the beam reaches its brightest. -Hit “ABCC” to readjust brightness. -Repeat using Y-Align knob (Fig.A1-Y) on the end of the column. BE CAREFUL! You can lose the beam entirely if you go too far. You must now perform the following alignments:

Begin Beam Alignment:

-Begin with a magnification of 1000x – 5000x. Once you complete the alignment at that zoom, repeat this whole process a second time at twice your desired magnification. -Apply the KV and probe current settings desired for operation -FIRST, perform normal focus and stigmation operations without opening the align window. The system must be relatively focused before attempting to align it. -Now open the alignment window. (Fig.A2) -The functions of the “X and Y Dials” (Fig.A3-X,Y) on your dial panel will change as you move down this list of radio buttons to adjust various condensers and apertures.

Figure A1. Mechanical Alignment

-X -Y

Figure A2. Beam Alignment

X Y

Figure A3. Alignment Controls

APPENDIX 1 continued Aperture Alignment:

-Move to a distinct edge or small feature. And activate “Aperture Align” Radio button. (Fig.A4-A) -The “Wobbler” mode is activated to exaggerate motion and assist you in aligning the aperture. Using the “Red1” scan mode will limit your vision and help you stay focused on one location. -Move the stigmator knobs on the Dial panel (Fig.A3-X,Y ) to minimize image movement. Movement onscreen should appear to be a flashing motion in one location-not a rocking motion. If you have to turn the dials too far, return to the mechanical alignment adjustors first. (Fig.A1)

Beam Alignment: -Select “Beam Align Tilt” (Fig.A4-B) -Turn “X” and then “Y” stigmation knobs until maximum brightness is achieved -Repeat on “Beam Align Shift” (Fig.A4-C)

Stigma Alignment: -If the beam has been running for awhile, you may need to Degauss (Fig.A5-A) the image before beginning for best results. -Stigma Align X (Fig.A4-C): Adjust BOTH X and Y stigmation dials (Fig.21-X,Y) to minimize rocking movement. -Stigma Align Y (Fig.A4-C): Adjust BOTH X and Y stigmation dials -3rd Step: repeat as needed until image just appears to move in and out towards you, not in X or Y directions. -Close alignment window AND repeat Degauss step,

NOW-Repeat the Beam Alignment Procedure at 2 x Your Desired Magnification for Best Results

Figure A5. Beam Setup-Degauss

-A

-A }B }C

Figure A4. Beam Alignment

APPENDIX 2: Using Variable Pressure Mode This mode allows you to view uncoated, non-conductive specimens by suppressing charging.

1. You will need a higher KV to use this mode, usually 10-25 KV with W.D. = 5-10 mm and probe current above 50. You need lots of energy to view in this mode as many electrons are lost to interfering air molecules.

2. Before viewing on VP mode, set up the beam first using a control sample on regular SE mode-SEE APPENDIX 1 OR GET HELP. Focus, stigmate and align the beam as for normal SE imaging.

3. Turn KV Off. 4. Under Conditions Tab, select VP-SEM. (Fig A6). The

syetm will automatically set itself to BSE mode now. 5. Set vacuum to 30-50. (Fig A6). Lower vacuum is more

efficient at charge reduction as air molecules absorb some charge.

6. NOW evacuate the chamber and switch to the test sample.

7. Turn KV back ON. You will need to focus on Slow 1 or Slow 2 mode. Fast is too noisy to see anything.

8. On the Image Tab adjust your BSE Gain setting (Fig A7) to 3 or 4 until you see an image.

9. COMP mode highlights composition, TOPO highlights topography, and 3D brings out 3-dimensional details. Going into the Detail window will open additional controls of the 5 detectors used for BSE imaging.

10. DO NOT ADJUST STIGMATORS ON THIS MODE-use fine focus only! Stigmation should have been done on the control sample first. Your focus will become quite poor if you try to adjust this on BSE mode.

Figure A6.VP-SEM

Figure A7. BSE Controls