Purpose:  To deposit a conformal layer of metal or dielectric to the surface of a sample

Location: Marcus Inorganic Cleanroom

Tools: Denton Discovery, CVC DC Sputterer, PVD RF Sputterer, Unifilm Sputterer

Supplies Needed: targets, kapton tape (if necessary), tweezers, vacuum, isopropanol, texwipe, multi-meter, test wafer/ wafer pieces, witness wafer/ wafer piece

Setup Parameters

1. Schedule time well in advance
2. Know the required powers for sputtering the material you want to deposit
3. Check that the back of the sample is clean and the front of the sample is free of any unwanted debris
4. Vent and clean the chamber
   • Vacuum inside the chamber
   • Wipe down the o-ring and the chamber with isopropanol and a texwipe
5. Clean off the target with isopropanol and a texwipe
   • Check the target thickness prior to insertion in the tool.
6. Insert the target into the tool
7. Test the target with a multi-meter
   • After putting the target in the tool, place one prong of the multi-meter on the target and one on the shutter or side of the chamber
   • Make sure the multi-meter is set to measure continuity
   • If the multi-meter measures a resistance (it should measure overload), the target is shorting and not inserted correctly
   • Reseat the target and try testing for a short again
   • If this becomes a problem and you can’t get the target to stop shorting, please contact the staff
8. Make sure that the rotostrate is turning before closing and pumping down the tool
9. Run a deposition test on the tool
   • Using an extra clean wafer or wafer piece with a strip of tape across it, run the tool for a 5-10 minute deposition
   • Measure the deposition with a profilometer and determine the deposition rate
   • Calculate how long the process step must be run for the deposition thickness desired

Number of Substrates: < 1- 6 (4” wafer size)

Process Procedures

1. Allow enough time for the tool to pump down to process pressure
   • This will typically take 30-60 minutes
   • Make sure the tool gets down to at LEAST the 10^-5 Torr scale
2. Make sure the plasma starts (if the tool has a view port)
3. Check the power, current, gas flows, and pressure
4. Watch the plasma to make sure it does not flicker or change color during the run (If the tool has a view port)
5. Take note of the parameters both set point and actual
6. Remove the sample and measure it to check the thickness of the deposition
7. If the deposition is not as thick as desired, calculate the deposition rate of the process. Use this to figure out how much longer the sample needs to be run
8. After the process is finished, remove the target and put it in the appropriate storage location. (dry box or the table with a slot for each target)
9. Clean up the tool if necessary (Vacuum and wipe with texwipe and isopropanol)
10. Pump down the tool and cancel any unused time that was scheduled
11. If there is a log book for the tool, fill it with all of the required information from your process.

Verification:

• Sheet Resistance: can be measured with the Signatone Four-Point Probe
• Film Thickness: can be measured accurately with Nanospec Refractometer or the Woollam M2000 Ellipsometer
• Film characteristics: can be measured with the Woollam M2000 Ellipsometer
• Step Height: can be measured with the Dektak 150 Profilometer, Tencor P15 Profilometer, or the Wyko Profilometer NT3300