Specific Process Knowledge/Wafer cleaning/IMEC

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The user manual, user APV and contact information can be found in LabManager: Buffered HF-Wetting agent/IMEC info page in LabManager

The IMEC process is used for cleaning of wafers prior to fusion bonding:

This procedure is based on the IMEC cleaning process: M. Meuris et al. "The IMEC clean: A new concept for particle and metal removal on Si surfaces.", Solid state Technology, Vol. 38, Issue 7, pp 109-113, 1995.
Has been slightly modified by Karen Birkelund.

Step	Process	Details	Comments	Comments
1	Pre-bond cleaning of Si wafers prior to fusion bonding.	.	Takes 1½ hours Orient flat to minimize handling Preferable done just before bonding!	Get CLEAN box for wafers!!!
2	Piranha	Mixture: H2SO4:H2O2 (4:1) Temp: 80 oC Time: 5 min (a yellow and a black spot)	Clean tank (cleanroom B1, 7-up bath for wafers) and make your own or make in dedicated glass. Pour up H2SO4 first, put wafers in carrier (USE this in steps 2-7), add H2O2, wait 30 sec, dip wafers.	Maybe clean the tank the day before!
3	Rinse	2 min. rinse	.	Put into dedicated wet box for IMEC
4	IMEC	DI water:5% HF:isopropanol (100:10:1) Temp: 25 oC Time: 100 sec (two black spots)	Clean tank (cleanroom D-3, tank for buffer with wetting solution) and make your own. Mix in dedicated bottle (IMEC) in fume hood and add to tank using BHF pump from RCA fumehood!	.
5	Rinse	2 min. rinse	Put into dedicated wet box for IMEC	.
6	Piranha	Not nitride wafers! Mixture: H2SO4:H2O2 (4:1) Temp: 80 oC Time: 20 min	Re-use previous piranha Makes wafers hydrophilic	.
7	Rinse & spin dry	5 min rinse	.	.
8	Put wafers in new clean carrier box	.	.	.