Silicon wafers are the heart of many devices thanks to their use in semiconductors. Most people are aware of that fact, but most aren’t aware that these components are incredibly delicate and need specialized cleaning so they can be used as intended.
At Polishing Corporation of America, we are a silicon wafer manufacturer that knows the ins-and-outs of cleaning wafers, and we’re happy to share that knowledge here.
The first thing you need to know is that wafers can become contaminated through simple exposure to the air. Their robust electrostatic forces are directly at odds with organic particles in the air, and that’s why they require precise cleaning before they can put into use.
Using solvents is an instrumental first step for cleaning wafers, but it leaves a residue itself. Applying acetone removes oils and organic compounds while following that with methanol removes the acetone.
Next, the silicon wafer manufacturer uses an RCA-1 cleaning bath of ammonium hydroxide and water to remove additional organic compounds. This creates a thin oxide layer on the wafer.
Finally, to remove the oxide layer, the manufacturer takes one more step to clean the silicon wafer. This involves using a hydrofluoric acid dip to remove the oxide layer. This three-step process is useful for eliminating contamination and can be used by manufacturers both large and small.