As we become more dependent on our notebooks, smartphones and laptops, the demand for the integrated circuits to power our devices will climb. So will the price of thin silicon wafers used in the semi-conductors that power them.
To cut costs, many semi-conductor manufacturers resort to “reclaiming” their test-quality thin silicon wafers. They’re the slightly less-than-perfect wafers the companies use to monitor and cast their semiconductor manufacturing equipment.
Priced at approximately $100 each, these test wafers cost less than a third of the prime-quality wafers used to make semiconductors. Top semi-conductor makers can drop close to $25 million in a single year on their test wafer supply. So it’s no wonder that–instead of replacing them–they send the used ones out for reclamation.
How Are Thin Silicon Wafers Reclaimed?
The semiconductor companies ship their used wafers to qualified reclamation facilities. There they undergo an extensive process designed to separate all the wafers that are beyond reclamation before restoring the remainder.
The Reclamation Process
Upon reaching a reclamation facility, the test wafers are thoroughly inspected for scratches and chips. Unsalvageable ones are discarded and the rest are measured. Those thick enough for reclaiming are then run through chemical baths that clean their surfaces of patterns and films,
Then comes the silicon wafer polishing process. Its job is to return the test wafers to usable condition without destroying an excessive amount of silicon. After polishing, the wafers face a second chemical bath followed by a rinse in purified, de-ionized water.
The Final Check
Polished, washed, rinsed and dried wafers are checked again for defects. Their final stop is at a Class 10 clean room, where they’re carefully packaged for shipping.
The Future of Thin Silicon Wafer Reclamation
As demand for their services soars, reclamation companies are collecting, restoring and shipping thousands of thin silicon test wafers daily. And as long as people continue their love affair with silicon-based devices, that’s not about to change!