CHA 3
CHA 3 is very similar to, if not easier than, CHA 1 and is used to evaporate metals (with exception of copper). You will most likely need to be trained on CHA 1 to be able to use this tool.
Allowed materials: metals (besides Cu - no dielectrics)
Supplied metals: Ti, Cr, Ag, Ni (all other, like Au and Pt - use our own proper crucibles from the metal toolbox)
There is also shorter distance between crucible and sample.
General Description of the Interface (refer to the picture below):
Generally, the Green Box is your Process Control, which you will be using the most. The Red Box is your Sequence control - Rico wants everyone to make sure the sequence is the same as it is preset at the end of your tool use, so if you do change something, change it back before you are done! (We’ll cover the changes further in the intructions)
The Yellow box is your gun control - you do NOT need to use it, unlike CHA 1, the only thing you need it for is to turn on the power to the Gun.
There is another Power Switch on the bottom right for the whole system - Main power.
Procedure for Use:
When you start, check that the tool is in the Auto Mode in Process and Sequence, if not, switch to it. (The mode you are in the within the Red box is the mode on top - so if it says Auto/Manual = you are in Auto, if it says Manual/Auto = you are in manual. )
Turn on the breakers for power - main power first, then the gun power.
Start Vent (takes about 8 mins) - prepare your sample in the meantime.
You can grab and clean a 4 in wafer from the wafer waste and place your sample on it with kapton tape and then wedge the wafer (with your sample) in the side of one of the holders. The sample holders can hold full 4 in and 8 in wafers with water cooling on the back (this CHA does not have a thermocouple inside, so you don’t need to watch the temperature and stop your process, but on the flip side you do not know how hot your sample gets and if your PR will bake.) If you want to mount with the thermal cooling on an 8 in or 4 in wafer - talk to Rico since you’ll have to take out the sample holder and it’s a finicky process.
When vent is done, click Standby.
Unlock - to unlock the door - might take another few mins to get to the atmosphere.
Load your wafer.
(IMPORTANT) Take out the shutter and vacuum it with vacuum cleaner - a lot of residue might remain - likely contamination.
Put shutter back.
(Optional) If using metals that are not supplied (like Pt and Au), replace the crucible. You can see the metals and corresponding pockets on red box by going to: Main menu - Next menu - process menu - first 6 metals correspond to respective pockets. Platinum is pocket 5.
On green box - Shutter Open - Select Pocket - click on Select Pocket - put in number you want - Done - Close Shutter.Close the chamber door and Lock the door on green box.
Click Start Pumpdown
Leave for at least half an hour (Rico encourages to let the pumpdown happen for an hour.)
After pumpdown is below 5e-6 (it won’t let you do anything otherwise), click AutoRun.
Click Sequence - select metal number by clicking on the number that pops up - Process OK.
If you need to edit the film thickness (again, remember to edit it back after you are done) you can do so in the red box iterface
Quick Edit - Film Thickness (2nd row) - use the rotational knob to change and press to ok.
If you need to start the deposition at lower power before the spike (Auto opens the shutter at around 0.7A/s), change into Manual (on the red interface) once Soak 1 is finished - can control power rise yourself - shutter will automatically open as you switch to manual. If want to rise back to 1 A/s - can click back to Auto.
After deposition finishes, let the system cool down for 10 mins.
If you need to switch to a new metal
Finish run
Process sequence
Abort - OK
Start Autorun and choose your new metal/sequence number. Repeat steps [14-16]
Once cooled down, Start Vent.
Unlock
Take out your samples and metals, if used ours.
Lock
Start Pumpdown
Check crystal life
Next Menu on red interface - Sensor Info - should be below 80 % - if approaches 80%( >75% - let Rico know - we do not know how to switch crystals yet - this will be updated when we do.)