MTL Fabrication

Perkin Elmer - Standard Operating Procedure


CORAL Name: perkin-elmer
Model Number: Perkin-Elmer Sputter system
Location: TRL
What it does: sputterer
Introduction: The Perkin-Elmer deposits metal Using a DC magnetron to strike an Ar plasma and sputters the target material onto 4, 5 or 6 inch wafers or wafer pieces. There is a reversible table that can hold 6 inch wafers on one side and 4 or 5 inch wafers on the other.  The table rotates and is set to rotate at 10rpm.  The system is capable of hoUsing 3 different targets; we currently have one Au target and one Ti target, while the other target is either Al or Cu depending on demand.
Safety: The power supply is capable of supplying ten thousand watts of power to the target assembly. This system is designed with a full array of electrical interlocks that should at no time be defeated or overridden. You should not remove any panels or attempt any repairs on the system.
Procedure:

If you need to do either Al or Cu deposition, please check the maintenance section on Coral to see which target is currently installed.  If you need the other target installed, please contact Eric Lim (x3-6897, eslim@mtl.mit.edu) to have the necessary target installed.

  1. Engage system on CORAL. The CORAL interlock disables the hoist for the chamber, so you must be engaged in order to load or unload your samples.
  2. Make sure ac power enable and hoist power enable toggle switches are on and the indicator lamps are on.
  3. Make sure the hivac, slow rough and fast rough valves are closed (down), the Ar valve toggle switch is off (down), table motor is off, and the throttle valve rotary switch is set to “open”.
  4. Turn off the ion gauge (open the panel for the ion gauge controller and press the IG1 button)

    Loading
  5. Bring the chamber up to atmosphere by opening the vent valve (toggle switch up).
  6. When the convectron gauge pressure reads 760Torr (7.6e2) use the “hoist up” switch to raise top until the red “Chamber lid open upper limit” lamp turns on. 
  7. Close the vent valve.
  8. Load wafers onto tray, deposition side up.
  9. Lower hoist Using the “hoist down” switch until the green “Chamber lid closed lower limit” lamp turns on. Make sure the chamber lid is centered over the lower chamber as you close it.
  10. Open the slow rough valve.
  11. When the convectron gauge pressure reads below 450T (4.5e2) open the fast rough valve.  Leave the slow rough valve on as well.
  12. When the convectron gauge pressure reads below 50mT (5e-2), close both the fast and slow rough valves and open the hivac valve.
  13. The ion gauge should automatically turn on once the convectron reads below range (below 1e-4).  If it does not come on, open the ion gauge control panel and press the “IG1” button to turn it on manually.
  14. After roughly 2 hours, the chamber should pump down to around 3e-6, and you are ready to begin deposition.

    Deposition
  15. Turn the magnetron key from “off” to “program”.
  16. The unit should start beeping and the vacuum and water LEDs and the “off” button should be blinking.  Press the “off” button to clear the alarms, the LEDs should stop blinking.
  17. Program power and time parameters for the appropriate target (target 1 for Al or Cu, target 2 for Ti, and target 3 for Au). Please see the “Recipes” appendix at the end of the SOP for specific process conditions. All adjustment to the power and time settings are done with the rotary knob on the magnetron control panel. To set the power level, press and hold the “Level” button and adjust with the rotary knob.  To set the ramp time, press and hold the “Ramp” button. To set the deposition time, press and hold the “Ramp” button, then press and release the “Setpt” button. The Ar flow, pressure setpoint, and table rotation speed should not be adjusted.
  18. Once the recipe is programmed and the tool has reached base pressure (typically around 3e-6 range), open the Ar valve. The flow should read 50sccm.
  19. Turn the throttle valve rotary switch to the “Auto” position.  The manometer readout should stabilize at 8 mTorr.
  20. Start table rotation.  Knob is marked at the 12rpm position. Do not adjust.
  21. Enable magnetron with magnetron power toggle switch. The magnetron enable indicator lamp should come on.
  22. Move the target shutter to pre-sputter position (any target other than your deposition target.)
  23. Switch the magnetron display to read minutes.  You can toggle through the parameters by pressing the “actual” button.
  24. Start the pre-sputter by pressing the “on” button on the magnetron panel.  You should be able to see a plasma up near the target when you open the view port shutter.  The power output should be ramping up, and the timer should be counting down from the programmed ramp/pre-sputter time.  The output, plasma, and ramp status LEDs should be on, along with the water and vacuum status LEDs.
  25. If you do not see plasma and/or the plasma indicator lamp on the magnetron control panel isn’t on, you shut off the Ar momentarily and turn it back on. This creates a short pressure spike which can help with plasma ignition.  This tends to happen more for Ti deposition than for any other film.
  26. When the ramp/pre-sputter time has elapsed (the machine will beep and the ramp led will go off, the setpt led should come on) move the target shutter to appropriate target.  The timer should be counting up to your preset deposition time.
  27. The power will turn off automatically when the step time has elapsed. At this point your deposition is complete.

    Unloading
  28. Turn off the “magnetron enable” toggle switch.
  29. Turn the throttle valve rotary switch to “open”.
  30. Stop the Ar flow by turning flipping down the Ar valve toggle switch.
  31. Stop table rotation.
  32. Close the hivac valve, and make sure both roughing valves are closed.
  33. Let the system pump back down to base pressure (typically around 3e-6)
  34. Turn off the ion gauge
  35. Open the vent valve.
  36. When the convectron gauge pressure reads >760Torr (7.6e2) use the “hoist up” switch to raise top until the red “Chamber lid open upper limit” lamp turns on. 
  37. Close the vent valve.
  38. Unload your wafers.
  39. Lower hoist Using the “hoist down” switch until the green “Chamber lid closed lower limit” lamp turns on. Make sure the chamber lid is centered over the lower chamber as you close it.
  40. Open the slow rough valve.
  41. When the convectron gauge pressure reads below 450T (4.5e2) open the fast rough valve.  Leave the slow rough valve on as well.
  42. When the convectron gauge pressure reads below 50mT (5e-2), close both the fast and slow rough valves and open the hivac valve.
  43. Disengage the system on CORAL.

If you have any problems or questions, please contact: Eric Lim (primary) x3-6897eslim@mtl.mit.edu or Bob Bicchieri (backup) X3-6418bic@mtl.mit.edu

Recipes

power

ramp time*

Ar

pressure

table rotation

rate

(KW)

(min)

(sccm)

(mTorr)

(rpm)

(A/min)

Al dep

2

2

50

8

12

325

Au dep

1

0.5

50

8

12

400

Ti dep

1

2

50

8

12

120

Cu dep

2

2

50

8

12

320

* The ramp time is important because we use it as our pre-sputter time to clean the target surface of any oxidation before deposition.
Author: Eric Lim, 10/14/05