IBM has begun to
recycle the waste silicon from one of its chip manufacturing
plants to provide a source of silicon wafers for making solar
panels.
A new
process introduced in its Vermont manufacturing facility has
enabled IBM, to repurpose scrap semiconductor wafers - thin discs
of silicon material used to imprint patterns that make finished
semiconductor chips for computers, mobile phones, video games, and
other consumer electronics - to a form used to manufacture
silicon-based solar panels. The new process uses a specialised
pattern removal technique to reclaim the silicon.
The process enables these wafers to be made available either for
reuse in internal manufacturing calibration as "monitor wafers" or
for sale to the solar cell industry. IBM has estimated the process
would resulting annual savings of £725 million by enabling the
company to reuse the spent silicon.
The process is now being deployed at IBM's East Fishkill
semiconductor fabrication plant.
IBM has estimated that up to 3.3% of the 250,000 wafers used by
the semiconductor industry each day are scrapped. In the course of
the year, this amounts to approximately 3 million discarded wafers.
Because the wafers contain intellectual property, most cannot be
sent to outside suppliers to reclaim so are crushed and sent to
landfills, or melted down and resold, IBM said.
The wafer reclamation process produces monitor wafers from scrap
product wafers. IBM said this generates an overall energy savings
of up to 90% because repurposing scrap means that it no longer has
to procure the usual volume of net new wafers to meet manufacturing
needs. When monitors wafers reach end of life they are sold to the
solar industry. Depending on how a specific solar cell manufacturer
chooses to process a batch of reclaimed wafers - they could save
between 30% and 90% of the energy that they would have needed if
they had used a new silicon material source, IBM said.