Specific Process Knowledge/Wafer cleaning/IMEC

From LabAdviser

IMEC process for cleaning of wafers before fusion bonding:


Step Process Details Comments Comments
4.0 Pre bonding cleaning of Si wafers with cavities and SOI wafers with nitride Use wafers with cavitys on and SOI wafers

Takes 1½ hours Orient flat to minimize handling Preferable done just before bonding!

Get CLEAN box for wafers!!!
4.1 Piranha Mixture: H2SO4:H2O2 (4:1)

Temp: 80 degC Time: 5 min (en gul og en sort prik)

Clean tank (cleanroom 4) and make your own or make in dedicated glass.

Pour up H2SO4 first, put wafers in carrier (USE this in steps4.1-4.6), add H2O2, wait 30 sec, dip wafers.

Maybe clean the tank the day before!

Put into dedicated wet box for IMEC

4.2 Rinse 2 min rinse Put into dedicated wet box for IMEC
4.3 IMEC DI water:5% HF:isopropanol (100:10:1)

Temp: 25 degC Time: 100 sec (to sorte prikker)

Clean tank (cleanroom 4) and make your own, it needs 2 bottles

Bottle in service room 2 on the left, pump by Leica microscope in cleanroom 3

Bottle for mixing is in service room 2, use bHF pump from RCA fumehood!

Put into dedicated wet box for IMEC

4.4 Rinse 2 min rinse
4.5 Piranha Not nitride wafers!

Mixture: H2SO4:H2O2 (4:1) Temp: 80 degC Time: 20 min

Reuse previous piranha

Makes wafers hydrofilic

Put into dedicated wet box for IMEC
4.6 Rinse & spin dry 5 min rinse Put into dedicated wet box for IMEC
4.7 Put wafers in new clean carrier box