Specific Process Knowledge/Wafer cleaning/IMEC
Feedback to this page: click here
The IMEC process is used for cleaning of wafers prior to fusion bonding
The IMEC cleaning process is used in circumstances where extraordinary clean wafers are required. It is primarily intended for cleaning 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.
The user manual, user APV and contact information can be found in LabManager: Buffered HF-Wetting agent/IMEC info page in LabManager
| Step | Process | Details | Comments | Comments |
|---|---|---|---|---|
| 1 | Pre-bond cleaning of Si wafers prior to fusion bonding. | . |
|
Get CLEAN box for wafers!!! |
| 2 | Piranha | Mixture: H2SO4:H2O2 (4:1)
Temp: 80oC Time: 5 min (a yellow and a black spot) |
You can use the 'Mask Clean' bath in Wet Bench 04 (in cleanroom D-3). However, this requires planning at least a couple of days in advance, since the bath is primarily used for other purposes!. Alternatively use a very clean glass beaker.
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 | . | . | . |