The oxides sputtering system is a epitaxial-growth high-pressure non-magnetron sputtering system with specially adapted sources that operate at pressures up to 5 mbar! The background pressure is typically <1e-6 mbar after a night of pumping and 1e-7 mbar is the minimum. The system is equipped with a 1200 C substrate heater that can rotate over the sources. Oxides are sputtered reactively, a 3-gas blending system for Ar, 0₂ and N₂ is mounted as well as special gas inlets for annealing. The power supplies are 2 slow-ramping DC supplies and a self-matching RF supply.

Safety issues for yourself and for the system:

• Before sputtering, make sure that all power supply cables are connected
• When pumping down, switch off cooling water for the sources and x-tal
• When starting, make sure the interlocks are wired correctly. Do not plug 2 power supplies in the connector for the same cooling water loop!
• After that, check flow meters and switch on cooling water for the sources and x-tal

oxide_YBCO

1. Check whether all gas inlet valves are closed
2. Close the gate valve
3. Switch off the pumps with the central pump switch
4. Switch off the cooling water

1. Vent the chamber
   1. open N₂ chamber valve
   2. turning the gas selector valve to N₂ 5.0
2. Close both valves when the pressure is 8e2 Torr.
3. Switch on the Lift main switch
4. Raise the top of the system using the lift control unit and rotate the top to the left.

1. ALWAYS wear gloves when touching substrates and system parts
2. Remove the heater shield
3. Remove samples, clean sideplates in HNO₃
4. Clean the heater surface
   1. with a razor
   2. 400 grit sandpaper
   3. 800 grit sandpaper
   4. Scotchbrite
   5. Clean with IPA. This step is crucial!
5. Mount the sample with SPI silver paste plus II (should be kept in freezer, warm up before use) and squeeze the substrate against the heater with the glass tool (clean before use)
6. Cut away glue around the substrate
7. Mount side plates, push them flush against the substrate using a cotton tip.
8. Set the heater to 80 C for 1 hour using the Eurotherm control software
9. Dry for >1 hour
10. Mount the heater shield, blow possible dust particles away with N₂

1. Rotate the top above the chamber and lock it in place
2. Lower the top very carefully making sure that the teflon guides slide along the chamber (take into account safety rules for working with heavy objects)
3. Switch off the lift main switch

1. Open the gate valve
2. Switch on diaphragm pump
3. Wait until the pressure is about 5 torr on the pirani or 8 mbar on the capacitance gauge
4. Switch on cooling water
5. Switch on turbo
6. At 800 Hz: open main gas valve under the chamber
7. Check that the ion gauge switches on
8. Pump overnight

1. Pressure <1E-6 mbar
2. Position heater between 2 sources, opposite to Target
3. Open N₂ purge on the pump. Do not forget this!
4. Open the O₂ valve at the front of the system. (Do not touch the O₂ needle valve! Flow should be around 40.)
5. Adjust Turbo speed to regulate pressure
6. Open the Target shutter, keep other shutters closed (unless you make a multilayer of course)

1. check cooling water
2. Switch on power supply, power regulation
3. Switch on matching power supply
4. Check for no reflection when turning power up
5. Let everything stabilize

1. Switch on the target power supply, current regulation
2. Set the setpoint at 8 ma, display actual current and voltage
3. when pressure is right, switch power supply to on. The plasma should ignite. Get help if it doesn't!
4. Let the pressure increase until the voltage gets below 350-380 V (the lower the better!)
5. The voltage keeps decreasing, keep it constant at 350-380 V by increasing current (it is critical that you follow this rate given by the O₂ backfill rate of the chamber and not faster!
6. Keep increasing current, set current to 350 mA (never get above 390 V!)

1. You will see that the conditioning of the target takes quite a while, check that while conditioning the voltage goes down to about the previous value in the logbook.
2. Presputter for >1 hour
3. Program the heater in the meanwhile.

1. Run temperature the recipe
2. When temperature is reached, turn sample above target.
3. Start a timer.
4. Time the epitaxial growth process

1. Turn off power supply
2. Cool down sample

1. Close O₂, if not done already
2. Let pump run for 20 minutes
3. Close N₂ purge on the pump.
4. Wait until the sample temperature is <50 C
5. Check whether all gas valves are closed

• Targets: 2 inch OD, 0.125 inch thick
• Backingcup: 53mm OD, 6.3mm thick