System Options: EasyLift
C O N F I D E N T I A L – FEI Limited Rights Data7-22
Welding the membrane to the Grid
In this procedure, the membrane is placed on the (usually copper) grid used for a TEM observation (TEM grid) and
they are welded together with tungsten or carbon.
1. Switch to the 100 pA beam current.
2. Position the stage to the TEM grid.
3. Find the eucentric position of the TEM grid spot where the
membrane will touch down.
4. Adjust the stage tilt to 0°.
5. Lower the stage by 2 mm below the eucentric position.
6. Insert Carbon or Tungsten GIS needle.
7. Insert the EasyLift needle.
8. Position the EasyLift needle tip to the eucentric position /
beams coincidence. Raise the stage up close to the eucentric
position.
9. Place the membrane inside one of the TEM grid notches by a
slow X, Y and Z stage movement. Monitor the distance
between the membrane and grid while bringing them together
with the use of the electron beam.
10. Bring the membrane and TEM grid to vertical alignment. Move
the stage in X and Y until the grid is directly beneath the
membrane (electron imaging).
Monitor the distance between the membrane and grid while
aligning them (ion imaging).
11. Iterate between the ion and electron imaging while moving the
stage until the membrane touches the grid.
12. Deposit 5 × 4 × 1 µm metal boxes at the two contact corners.
Leave the GIS needle in place when welding is complete.
13. Select the 1 nA beam current and mill a small rectangle
(0.5
µm in Y) through the weld connecting the EasyLift tip and
the membrane to free the tip.
14. Lower the stage in Z direction.
15. Move the needle to the Park position.
16. Retract the EasyLift needle.
17. Retract the GIS needle.
FIGURE 7-7 Sample Reinforced with Tungsten Welds
Final Thinning
During final thinning, leave some material at the membrane base to provide structural support. Begin with a
relatively low beam current (1 nA or less) to avoid damaging the membrane.
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