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.