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FEI FIB

Focused Ion Beam

Operating Manual

Part 2

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TEM specimen prep in FIB• The general process flow is

shown at left.

• In these instructions CO = “Click On”

• These instructions assume there are grids already mounted in the row holder and that the row holder is on the shuttle (i.e. not using flip stage). If you are not sure about this see Mick.

• The portion of these instructions referring to Automatic Cutout assumes AutoG2 TEM software is installed

First protection layer• If your area of interest is near the

surface (<~500nm) it is recommended that you use either a carbon coating (via a Sharpie® pen) or Pt E-Beam coating (or both) before running the automated procedure or manually adding an I-Beam Ptcoating.

Sharpie® Coating• Using a permanent Sharpie®

marker put as thin a streak across your sample as possible. For best results allow the ink to dry several hours or overnight. Proceed to E-Beam coating or I-Beam coating.Final thinning

Manual cutout

Put down a protective

platinum layer

Automatic cutout AutoFIB G2

10.00

Lift-out and mounting

How to prepare TEM samples in the FIB


• Launch. AutoTEMG2

• CO Create and make a file for info

• Select 15X10 thick liftout

• Basic Tab Settings:1. Width to15u 2. Thickness to1.5u3. Depth to 10u4. Ensure Skip Fiducials is not checked

• Advanced Tab Settings:1. Rough mill current to 9300pA 2. Cutout width to 0.8μ 3. Deposition height to 1.5 μ 4. Angle correction to 0 5. Depth correction to 1

• Process Control Settings:1. Perform rough mill step2. Do cutout is optinal3. Generally do not perform final milling

step

• A new window has shown up with a yellow box in it. Use beam shift controls to center Pt layer (just put down by E-Beam) inside yellow box. CO Mill Fiducials

• CO Ground to put grounding layer down

• CO Finish

• Confirm that both the 9.3nA beam and 0.28nA are focused outside your area of interest, lower beam current to 0.93pA and move back over area of interest.

• CO Run

How to use the Automated procedure10.20


If routine fails it is probably because:1. The I-Beam is not focused correctly at 9.3 A or 0.28 nA, and

it cannot recognize the fiducial marks. Move to a sacrificial area on your sample well away from your region of interest and refocus the I-Beam at 9300pA. Then pause I-Beam, move back to your region of interest using the E-Beam, and click on Run again. Bottom side must start first.

2. The Sharpie coating is too thick – try a region with thinner Sharpie or take sample out and re-coat with thinner Sharpie.

How to use the Automated procedure (continued)10.20


How to prepare a TEM sample manually

Check that a principal crystallographic plane is oriented parallel to your cut, if important.

Set eucentric height;

E-Beam coating (If desired)

• Set stage to 0 degrees for E-Beam deposition.

• Set E-Beam to 2keV and 3.4nA and check cross-over, refocus, stigmate. Set deposition window to 25μ (x) by 3μ (y) by 50nm (z).

• Deposit E-Beam platinum.

• Remove Pt needle

• Lower mag to 2000X; center the Pt coating mechanically and ensure the electronic shifts of the E-Beam are centered

.• Set E-Beam to 5keV, 1.6nA

10.20

It is important to recognize that proper TEM preparationconsists of “A thousand little tricks” all of which cannot possiblybe explained in this manual. Here are some very BASIC stepsto take when preparing a TEM sample.


• Turn on I-Beam and set it to 30keV, 0.28nA

• Check that I-Beam is focused and stigmated and centered on the same spot as the E-Beam, keep mag low.

• Take snapshot of ion image

• Set I-beam deposition to 25um by 3um by 0.5 to 1.0 um thick. If an e-beam deposition was done, then cover over same area as e-beam deposition.

10.20 How to prepare a TEM sample manually (continued)


• Set up Regular cross-section. The width (Y or vertical direction on screen) should be about two times greater than the Z depth.

• Start with 9.3nA beam and go close to the final edge but leave about 1-2 um for removal with a lower current ion beam.

• Lower the beam current to 2.8nA and tilt the sample to 54 degrees. Using a regular cross-section remove remaining material up to the edge of the Pt.

• Lower beam current to 0.92nA and cut about 0.5 microns into the Pt.



• Repeat process for the other side.

• When you are finished the sample should look like below, except without the fiducial marks.

• Final thickness before liftout should be about 1.5uM

How to prepare a TEM sample manually (continued)10.20


• Tilt the sample to 0 degrees.

• Set up three milling boxes as shown

• Beam current 0.92nA or 2.8nA

• Mill until all the way through on all rectangles

• Sample should look like sample on following page.



• After cutting through attach the Omniprobe needle as follows:

• Rotate scan in I-column 180 degrees.

• Lower I-Beam current to 28pA

• Set mag to 100X

• Insert OP – visible around 100X

SEM image X-Y controls:• L-R arrows move L-R,

FIB image X-Y controls:• L-R arrows move opposite direction

FIB image Z controls:• Up-down arrows move U-D



• Switch ion beam to 0.92nA or 2.8nA and cut off remaining support beam

• Reduce beam current to 0.93nA and lift lamella out



• Move sample to less than 0.5um from post and attach using a 93pA ion beam.



Switch to a 0.92nA beam and cut off the Omniprobe needle and retract it.

• Tilt to 52 degrees.

• Using a 30 keV ion beam at 0.92nA and a regular cross-section to mill away just enough material to establish a flat surface.

• Remain at 52 degrees and rotate the stage 180 degrees and mill the other side. Now you should have two very parallel faces.



• After milling the two parallel faces, tilt to 54 degrees. Lower the voltage to 5keV and 47 pA continue, using a Regular cross-section, to thin the lamella. Set Z depth to about 0.25 um. Repeat several times to create a “ledge” where the bottom of the sample is thicker, the top is thinner.

• To mill the other side rotate the sample 180 degrees, but do not change tilt angle.

• Repeat many times and gradually thin the sample. When the platinum layer just begins to get thinner, switch to Cleaning cross-section.

• When the platinum is about 0.25 um tall, lower the voltage to 2keV and the current to 89pA, re-align beam, increase the angle to 56 degrees, and use a Cleaning cross-section to polish further.

• If possible, a final polish on each side at 1keV and 5.3nA can help, but it may be very hard to see what you are doing..

How to prepare a TEM sample manually (continued)

Note that these final thinning steps are the most important steps andno amount of text or images can adequately explain what onlyexperience is able to teach you.

10.20

fei fib focused ion beam - ccmr.cornell.edu · mick: 255-0650mick: 255-0650 if in doubt ask if in...

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