Plassys Evaporator

Overview

Physical vapour deposition tool of aluminium via e-beam evaporation for Josephson junction fabrication.

It also provides an ion gun for surface preparation and etching purposes.

The system has the capability of in-situ oxidation.

The sample stage can be cooled with LN2.

Film Quality: Surface roughness - 1.6 nm for 100nm thick film ( scan area 2 um /AFM Analysis (June 2023)

Currently loaded materials

Crucible position	Material	Comment
1	Ti	Currently In Use
2	-	Empty
3	-	Empty
4	Al	NBI crucible
5	Al	NQCP crucible

Substrates allowed

• Silicon and Sapphire only
• III/V substrates are not allowed in the chamber

Standard Operating Procedure

This is the standard operating procedure for the Plassys evaporator at the process lab on the second floor.

Pre-checks and log in

Pre-checks

1. Is the oxygen alarm beeping?

   Leave the room immediately and notify the cleanroom staff

2. Log the loadlock and main chamber pressures in the Excel log sheet at the external computer.
   • P_LL ~ 1e-7 bar
   • P_main < 5e-8 bar
3. Verify that the turbopump and the cryopump are both running (check main software interface)
   • Turbo should be running on 100% speed
   • T_cryo should be in the range 12-15 K
4. Verify that nobody has loaded a sample and that no user is logged on

Log in

• Click on the logged off indication of the GUI and use your group's credentials to log in

Sample loading

1. On the - LL state - side of the user interface click VENT
2. Wait for the load lock to vent.

   The venting is complete when you stop hearing the hissing sound of the N2 line

3. Wear gloves. Sleeves and hair net are also recommended.
4. Use the stepping stool to have better access to the loadlock

   Be careful with the ventilation unit above the tool

5. Open the loadlock lid
6. Use the dedicated screwdriver to loosen the three main screws
7. Rotate the holder to release it from the main stage.
8. Place the holder on a cleanroom wipe on the stable
9. Close the LL lid
10. Clamp your substrate to the holder. There are many available holders. Use the one that your group recommends.

    Keep the unused holders in the N2 desiccator

11. Align the holder pin with the pin in the chamber. This will help you with any angled evaporations.
12. Tighten the screws with the dedicated screwdriver and place it back in its holder.
13. On the - LL state - side of the user interface, click PUMP

    The loadock will start pumping first with the scroll pump (up to 1e-1 bar) and then with the turbopump.

Load your recipe

While the loadlock is pumping down, you can prepare your recipe

1. Click on the Edit process icon
2. File > Open recipe> ... Choose from your group folde
3. Edit the main parameters such as time, thickness, and tilt
4. Save the recipe

   On the saved recipe name you automatically get the date added

5. Close the window

Excecute your recipe

• Are you doing evaporation?

  Turn on the Carrera power supply

• Are you doing milling?

  Turn on the Kaufman control unit and open the valve of the argon bottle

• Are you doing oxidation?

  Verify that the oxygen bottle valve is open

1. Click on the Run process icon
2. Load your recipe
3. Verify all your steps
4. Click Execute