Dear All,
Please some one explain me the how does standard cleaning mechanism RCA-1,RCA-2 cleans the Silicon wafers? How does it removes the metal Ions and organic residue?
What is the mechanism behind the cleaning?
Thank You
Manoj
Dear manoj
RCA (Radio Corporation of America) is a standard procedure to clean semiconductor wafers. For detail procedure you may refer the attached pdf files.
Dear Manoj,
You may have a look also at the classical paper from Werner Kern (inventor of RCA cleaning) at:
http://jes.ecsdl.org/content/137/6/1887.full.pdf+html
It is really clear and puts this method in context.
David
Dear Manoj, I guess this will be helpful to you. :)
Wafer Cleaning Standard RCA Process
Getting ready:
1. Clean RCA bench, all RCA beakers, quartz boat etc. with DI water.
2. Switch on the heater in the RCA bench
3. Submerge the quartz boat in DI water and take it to the laminar bench for wafer
loading
4.Arrange the wafers in the boat in such a way that the polished surfaces are
aligned in one direction
5. Fill 3 Teflon beakers with DI water and rinse the wafers 3 times in each of these.
6.Prepare the solution for ‘HF Dip’.This is a 2% HF solution. Fill the beaker for HF
Dip with 192ml of DI water and pour 8ml of 49% HF in to this.
Chemical Process:
Organic Clean:
RCA-1 Solution:-NH4OH:H2O2:DI Water.
1. Take 180ml of DI water and 25ml of NH4OH.
2. Heat this solution to 75-80 degree Celsius for about 5 minutes. This is to
increase the
chemical reaction rate.
3. Remove from hot plate and add 50ml H2O2(30%).Solution will bubble
vigorously after 1-2 minutes,indicating that it is ready for use.
4.Soak the silicon wafer in the solution and keep it for heating for 6-8 minutes.
5.Remove it and allow it to cool for 8-10 minutes.
6. Rinse the wafers 3 times in 3 DI water beakers.
7.Give a 30Seconds HF Dip.
8.Rinse the wafers 3 times in 3 DI water beakers [Use fresh DI water in each step]
9.Wait for the solution in the beaker to cool down for 1 hour.
10.Dispose the RCA-1 solution in the ‘Used RCA-1’ bottle.
Ionic Clean:
RCA-2 Solution:-HCl:H2O2:DI Water.
1.Take 180 ml of DI water and 25 ml of HCl.
2.Heat the solution to 75-80 degree Celsius for about 5 minutes. This is to increase
the chemical reaction rate.
3.Remove from hot plate and add 50 ml H2O2 (30%). Solution will bubble
vigorously after 1-2 minutes indicating that it is to use.
4.Soak the silicon wafer in the solution and keep it for heating for 3-6 minutes.
5.Remove it and allow it to cool for 6-8 minutes.
6. Rinse the wafers 3 times in 3 DI water beakers.
7.Give a 30Seconds HF Dip.
8.Rinse the wafers 3 times in 3 DI water beakers [Use fresh DI water in each step]
9.Wait for the solution in the beaker to cool down for 1 hour.
10.Dispose the RCA-2 solution in the ‘Used RCA-2’ bottle.
The wafer cleaning process is over. Take the wafers submerged in DI water to the
laminar bench and allow it to dry in the drier.
Very much helpful information from Shashikant Sharma . Thank you so much.
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