SEMC TF20, Руководство пользователя, Страница: 7 / 30

Last updated 10/29/2020
6
d. Close window
7.
“Cycle” presets to minimize hysteresis in the beam
a.
Under “preset manager” node, select “settings”
button and check the “cycle presets” option (see
image)
b. Send scope to EN preset 10X
8. Open shield of cryo holder. You may see a slight
increase in IGP1, but should settle within a few seconds
9. Open column valves when IGP <10
10. Center preset beams
a. Move to square of non-interest using the flu
screen and the stage track ball (square with
carbon that you don’t mind burning)
b.
Center “grid” preset beam
i.
Send scope to “grid” preset
ii. Lower flu screen
iii. Center beam using left trackball
iv.
Open the “Edit” box and click “apply beam shift from scope”
c. Repeat step b. for square and hole preset
d. Center and adjust intensity of FA/FC/EN preset beam
i.
Send scope to “EN” preset
ii. Lower flu screen
iii. For the EN preset, adjust beam diameter to ~1.5X the size of the second circle
and spot size until you achieve target dose of 40 - 70 e
-
/A
2
with 1 sec exposure.
iv. For the FA/FC preset you can make this beam a bit brighter and smaller
v.
Open the “Edit” box and apply intensity “from scope” and beam shift “from
scope”
vi. Repeat for FA and FC preset
11. Get eucentric height and focus
a. On a square of non-interest...
b.
“Z_focus” node→ simulate target (+ icon)
c. Recommended- record the eucentric height value; it is useful to have an idea of what the
eucentric height of your grid is, especially as you navigate around during data collection;
The eucentric height should stay relatively similar, +/- 50 um. This means your grid is
fairly flat.
d.
“Z_focus” node → MF (manual focus)
e. Click on the upside-down ‘42’ “Toggle show resolution/defocus” and check the defocus
at the first zero to see if the set defocus is roughly correct.
12. Collect atlas of your grid (this is a series of low mag images that are stitched together to give you
a whole view of your grid; ~10 minutes)
a.
Under the “Grid_targeting” node, click “settings” button (upper left hand side) and input
your grid description
i. Radius = 0.0009m = 0.9mm
b.
Click “calculate atlas”