Making solar panels from scrap
A reclamation process at IBM’s Burlington, Vt., plant uses an innovative pattern-removal technique to turn scrap semiconductor wafers into silicon-based solar panels, among other things.
The process removes intellectual
property from the surface of the
wafers so they can then be reused
as “monitor wafers” in internal
manufacturing calibration or sold
to the solar-cell industry. The
company intends to eventually
provide details of the process to
the broader semiconductor-manufacturing
industry.
“One of the challenges facing
the solar industry is a severe
shortage of silicon,” says Charles
Bai, chief financial officer of Rene-
Sola, one of China’s fastest growing solar-energy companies.
“This is why we use reclaimed
silicon from the semiconductor
industry for the raw material.”
According to the Semiconductor
Industry Association, 250,000
wafers are started worldwide
per day. IBM estimates that up
to 3.3% of these are scrapped.
This amounts to about 3 million
discarded wafers each year. Because
the wafers hold intellectual
property, most are crushed and sent to landfills, or melted
and resold.
Making monitor wafers from
scrap wafers generates an energy
savings of up to 90%. When monitors
wafers reach end of life they
are sold to the solar industry. Solar
cell manufacturers that process
reclaimed wafers could save
from 30 to 90% of the energy it
takes to process new silicon.
James Procopio, an IBM chip
manufacturing project manager,
holds a semiconductor wafer prior
to refurbishment, and Michelle Bolz,
an IBM manufacturing engineer,
displays a solar panel.