If you are using our gold source, write that we used our own source in the log book. Otherwise the cost of the gold (if over 50nm) may get added to our cleanroom bill.

Introductory notes and quick reference

1. The operating procedure is posted on the tool.

2. The crucibles are molybdenum and are a different size than the CHA crucibles. This means a CHA source cannot go in the KJL and vice versa.

3. If you need to fill a crucible, you should fill it about 2/3 of the way. Any less than 1/3 filled is too low. A lower fill level means it's more likely something goes wrong.

4. For gold, don't go over 3A/s. Preferably stick to 2A/s or less. This is gives us 180nm in about 17 minutes (really more like 25-30 minutes since you have to account for ramping/soaking).

5. Start with a low deposition rate for the first few nanometers to promote planarization. Stick to 0.5A/s or less (ideally 0.2A/s)

6. Do not touch random stuff on the screen unless you know what you're doing.

7. The golden rule: Let it soak. If you aren't sure if you should increase the setpoint yet, let the metal soak for another 60 seconds or so. The evaporation rate increases as the metal soaks.

Sample Loading

1. If you need to use our group's gold source, follow the Addendum at the bottom of this page.

2. Check that the metal you are evaporating is in the machine.

3. To vent the load lock, press "LL Vent" on the right side of the screen. Wait for the recipe to finish (bar at the top should turn green). This takes about 2 minutes.

4. While the load lock vents, you should mount your samples. Using kapton tape, secure your sample to the rough side of the handle wafer. If your sample is on a glass slide it is recommended to tape over the corners of your sample just to be safe.

5. Load the carrier wafer sample-down in the load lock. Make sure it sits properly in the slot.

6. Close the load lock and start the "LL Pump" recipe. This normally takes 5-10 minutes depending on the amount of tape you used. The recipe is done when the recipe bar turns green.

7. Run the "Sample Load" recipe. This will move the carrier wafer to the process chamber. It takes 1-2 minutes. Again, its done when the recipe bar turns green.

Deposition

1. Change to the material pocket you are using.

2. Check the reference sheet for the tooling factor, ramp rate, and set points for the material you plan on evaporating.

3. Double check that the e-beam shutter is open (the button should be blue). LISTEN to shutter open up! If not sure it's open, close and open the shutter - sometimes it glitches!

4. Set the tooling factor to the value on the sheet (for example: 120 for gold) below the "Accumulate" button

5. Turn on the electron beam

6. Set the ramp rate to the value on the reference sheet. DO NOT SET THE SET POINT UNTIL AFTER YOU SET THE RAMP RATE otherwise the tool will immediately reach that set point. This may cause the crucible to break.

7. Double check the ramp rate.

8. If you are using our gold, the set point is not the value on the sheet. Set to 4%, soak, and then increase by 0.5-1% with soaks between until you start seeing deposition. You will normally see deposition between 5.5-6%.

   1. We go slow here because it evaporates at a much lower power than the cleanroom source. As you get more comfortable with the tool, you can ramp our gold a bit faster but still be careful and remember to let it soak.
      
      

9. Set the set point to the first value listed on the sheet and let the metal soak for 2-3 minutes (until the metal turns orange). If two set points are listed, repeat this step for the second set point. 

10. Once you have a low but stable deposition rate (~0.2A/s), do the following. You should ideally do this within 2-3 seconds.

    1. Open the substrate shutter

    2. Press "Reset"

    3. Press "Accumulate

11. Deposit the first 2nm or so at this slower rate to ensure good adhesion and planarization.

12. Increase the set point in 0.5-1% increments until you reach a good deposition rate. Don't go over 3A/s but you shouldn't need more than 1A/s for anything thinner than 30nm. I've found 0.6-0.7A/s to be good for titanium and platinum, and 2A/s to be good for gold.

13. Record your maximum deposition rate and deposition power in the logbook.

14. When you reach your desired thickness,

    1. Close the substrate shutter

    2. Press "Reset"

    3. Press "Accumulate

15. Set the setpoint to 0%

16. Let the power ramp down.

17. Turn off the electron beam.

18. If you need, swap pockets and repeat steps 2-17

Unloading

1. Make sure the substrate rotation is off (it should be since we don't use it).

2. Make sure the electron beam is off.

3. Run the "Sample Unload" recipe. It takes 1-2 minutes.

4. Run the "LL Vent" recipe. It takes 1-2 minutes.

5. Take the carrier wafer out, close the load lock, and run "LL Pump". This is a good time to take your sample off of the carrier wafer.

6. Record the crystal power in the log book

7. If you loaded our' group's source, don't forget to unload it.

8. Log out of the tool

Addendum: How to change a source in the process chamber

Required if you are depositing more than 30nm of gold.

If you are using our gold source, write that we used our own source in the log book. Otherwise the cost of the gold (if over 50nm) may get added to our cleanroom bill.

1. Choose the pocket that you want to replace and make sure the source you are replacing is in the current position (it will be much easier to rotate the sources now than under atmospher.)

2. Run the "PC Vent" recipe. It takes about 5 minutes.

3. When the recipe finishes, the process chamber will still be closed. Turn off the PC Vent pump by clicking it on the monitor and wait for the process chamber pressure to read about 8.9E+02 Torr (turning it off means opening the valve in this case).

4. Open the process chamber door.

5. Change to the pocket you want to swap out. Remove the source and put it in the correct crucible box.

   1. If the source does not want to come out, you may need to slightly move the crucible holder. Press "Menu" on the manual pad and navigate to the crucible pocket screen to adjust the position slightly.

   2. You can also swap to a pocket with an easier to remove crucible. Just don't accidentally remove anything you may need.

   3. Note: Chromium is generally pretty easy to remove, which makes it a good candidate for swapping with our gold source.

6. Close the process chamber and latch the door. Turn on the "PC Vent" pump (close it).

7. Run the "PC Pump" recipe. It takes 15-20 minutes. Then proceed with sample loading and deposition as normal.

   1. Sometimes "PC Pump" recipe times up and throws an error. If that happens, Ack (acknowledge) the error and run the recipe again (sometimes 2 or 3 more times.)

Don't forget to remove our source when you finish. Once you start pumping the process chamber after replacing the cleanroom source, wait for crossover and then you can sign out.

Hints: 

If get an error messafe, do not click abort. Only click Ack (acknowledge). Abort turns off turbo and some valves practically bringing KJL into an idle state, will need to turn on those manually on the screen (to the state where valves/pumps are green as when started.)