The e-beam evaporator is a high vacuum deposition machine that heats materials with an electron beam. Due to the heat, the vapor pressure will increase until it has reached a value above the background pressure, after which it will evaporate. The substrate on which the vapor is deposited is roughly 60 cm away from the heated source, which allows for isotropic deposition (contrary to most sputtering techniques).

This e-beam evaporator can hold six crucibles with different materials, ranging from superconductors (e.g. Nb) to several types of magnetic materials (e.g. Co, Py) and adhesive/sticking laters (Cr, Ti).

Some notes on requests for using materials that are currently not loaded in the system:

• If you wish to evaporate specific materials, let the technicians know in advance (preferable a few weeks).
• Ordering new materials (that have not been used in the system) and setting up the evaporator for specific processes easily takes a few weeks.
• New materials are usually loaded on Friday afternoon, so please try to avoid booking the system in the afternoon.

The e-beam evaporator is controlled from the PC. But the e-beam evaporator can be controlled in two modes of operation: a manual mode in which you control the process steps with the computer, and in a recipe mode, in which you select a recipe, which the computer follows blindly. Most casual users have a working recipe ready, if you want to change recipes, you should contact the responsible technician.

The possible trainings for the e-beam evaporator are:

• Basic operations
• Building recipes
• Shadow Evaporation
• LN2 Cooling the Sample
• LN2 Cooling the Shroud
• Refilling, Liners and Materials (for technicians)

The first (safety) checks are necessary for every user:

• The three cooling water interlocks are OK.
• Cryopump has temperature of 12-13 K.
• Pressures should be:
  • Loadlock: ~1e-6 mbar, with the sample holder inside.
  • Process chamber: <1e-8 mbar.
• The required material is loaded in the evaporator.
• You've had a proper intro to the evaporator for the process you would like to do, if not, contact a research technician.

1. Log in to your account on the e-beam evaporator.
2. Vent the loadlock. Once the yellow light on the right side of the screen turns on, the loadlock is vented.
3. Put on some gloves, and obtain the sampleholder from the loadlock
4. Load your sample onto the sampleholder. This can be done by clamping your sample underneath the needles, or with the rectangular clamps.
5. Check whether your samples are firmly attached. You can check this by tapping on the back of the sampleholder.
6. Load the sampleholder in the loadlock, with your samples facing down. Make sure that the gold-coloured pin sticks through the elongated hole of the sample holder.
7. Close the loadlock and tighten it with at least the upper turning screw.
8. Pump the loadlock down to 1e-6 mbar.

The manual mode actually is a kind-of-manual mode, in which you operate the computer - you don't have to manually open and close the valves, the computer will control these subprocesses.

The following instructions can be followed after you have loaded your sample.

1. First, we transfer the sample from the loadlock to the evaporation chamber. Click the LL » Evap button in the Process Diagram.
2. Select the e-beam gun process.
3. Now we turn to the Xtal Monitor. Select the correct crucible (i.e. the required material).
4. Enter your desired thin film thickness.
5. Enter a target deposition rate, a common value is 0.10 nm/s.
6. Turn on the 10 kV high voltage.
7. Check your material's setpoint in table 1.
8. After waiting for a 1 minute, the high voltage switches on, and you can slide the horizontal scrolling bar slowly to the right, to increase the emission current of the electron beam until you have reached the desired setpoint
9. Close the lower viewport to prevent getting welding eyes (especially when evaporating Ti, Co, Nb, etc.)
10. When the deposition rate is roughly halfway towards the desired deposition rate, turn the Rate Control on.¹⁾
11. Once your required deposition rate is reached, click the Start button to initiate deposition.
12. Write the process pressure, deposition rate and thickness in the log book.
13. Once the thickness is acquired, the shutter will be closed, emission current will drop, and the HV will turn off automatically.
14. Wait for 2 minutes, so that the evaporated source can cool down.
15. You can either
    • Deposit another layer (go back to step 2).
    • Transfer your sample to the loadlock, and unload (continue steps).
16. In the Process Diagram, click the LL « Evap button.
17. After your sample is back in the loadlock, you can vent the loadlock.
18. Take the sampleholder out, using gloves.
19. Remove your samples, and place the sampleholder in the loadlock.
20. Pump the loadlock down.

Recipes can be useful for more complex processes.

To run a process with a recipe, simply follow the loading procedure described above, and click Run Process in the Process Diagram. This will open a pop-up menu in which you can select the specific recipe, and give a name to the log-file. When you run a process, you can abort the recipe, skip steps (with caution!), or pause the process. Once you abort a process, you cannot resume it.

The manual mode actually is a kind-of-manual mode, in which you operate the computer - you don't have to manually open and close the valves, the computer will control these subprocesses.

The following instructions can be followed after you have loaded your sample.

1. First, we transfer the sample from the loadlock to the evaporation chamber. Click the LL » Evap button in the Process Diagram.
2. Select the e-beam gun process.
3. Now we turn to the Xtal Monitor. Select the correct crucible (i.e. the required material).
4. Enter your desired thin film thickness.
5. Enter a target deposition rate, a common value is 0.10 nm/s.
6. Turn on the 10 kV high voltage.
7. Check your material's setpoint in table 1.
8. After waiting for a 1 minute, the high voltage switches on, and you can slide the horizontal scrolling bar slowly to the right, to increase the emission current of the electron beam until you have reached the desired setpoint
9. Close the lower viewport to prevent getting welding eyes (especially when evaporating Ti, Co, Nb, etc.)
10. When the deposition rate is roughly halfway towards the desired deposition rate, turn the Rate Control on.²⁾
11. Once your required deposition rate is reached, click the Start button to initiate deposition.
12. Write the process pressure, deposition rate and thickness in the log book.
13. Once the thickness is acquired, the shutter will be closed, emission current will drop, and the HV will turn off automatically.
14. Wait for 2 minutes, so that the evaporated source can cool down.
15. You can either
    • Deposit another layer (go back to step 2).
    • Transfer your sample to the loadlock, and unload (continue steps).
16. In the Process Diagram, click the LL « Evap button.
17. After your sample is back in the loadlock, you can vent the loadlock.
18. Take the sampleholder out, using gloves.
19. Remove your samples, and place the sampleholder in the loadlock.
20. Pump the loadlock down.

There are several types of liners. The most commonly used liner is the graphite liner, either with or without a copper adapter. Every material uses its own liner, since the choice of the liner is material specific.

e.g. heavy samples