Cleanliness or purity is one of the standards to consider if you’re looking for high-quality wafers. That is why silicon wafer processing is keen on making sure that the wafers are cleaned thoroughly to get rid of contaminants. If you need excellent quality wafers for your business, here’s how it is achieved:
The Cleaning Process
Materials:
Acid Apron
Safety Glasses
Neoprene Gloves
Safety Equipment
Hot Plate
Pyrex Bath Containers
Solvents:
Methanol
Acetone
Hydrogen Peroxide
Ammonium Hydroxide
Dilute Hydrofluoric Acid (2%)
Steps:
Solvent Bath
A two-solvent method is used to cleanse the wafers to get rid of organic residues and oils which could show on the surface.
In a glass container, pour the acetone and warm it up on the hot plate. Also, put the methanol on a separate glass container.
Soak the silicon for 10 mins in the warm acetone bath.
After 10 mins, remove the silicon wafer and put it in a glass container containing methanol for 2-5 mins.
This process is used to remove organic residues by oxidizing the silicon and leave some oxide on the surface of the water.
Materials:
65 ml H203 (30%)65 ml NH40H (27%)325 ml DI water
In a pyrex beaker, pour the 325 ml DI water then add 65 ml of NH40H (27%).
In a hot plate, heat the mixture to 70 +/- 5 deg Celsius.
After heating, remove from the hot plate and add 65 ml H202 (30%)
The solution is expected to bubble after a minute or two. This means that it is ready to be used
Soak the silicon wafer in the solution for 15 mins.
Put the wafer in a container with overflowing DI water from a tap to remove the solution.
HF Dip
Hydrofluoric acid is a dangerous chemical so proceed with precaution. HF gets rid of native silicon dioxide from wafers.
For 2 minutes, dip the wafer in a 2%HF solution.
Take the wafer and rinse it with running DI water
Curious about Silicon Wafer Processing?
Silicon Wafer Process is a multi-staged tedious process to produce the best quality wafers. At Wafer World, we have been serving our clients from all over the world for more than 20 years. Be a part of our family and contact us for any inquiries or purchase wafers online!
