X-bit labs

IBM Invents Technology to Turn Scrap Wafers into Solar Energy Panels.

Category: Other

by Anton Shilov

[ 10/30/2007 | 10:36 PM ]

IBM on Tuesday announced an innovative new semiconductor wafer reclamation process that helps to transform faulty semiconductor wafers into solar panels. Potentially, this reduces the cost of solar energy and generates some savings to chip manufacturers, however, it is unclear how many faulty wafers are actually generated.

The new process uses a specialized pattern removal technique to repurpose scrap semiconductor wafers – thin discs of silicon material used to imprint patterns that make finished semiconductor chips – to a form used to manufacture silicon-based solar panels.

Shortage of silicon constrains growth of solar panel industry: IBM has developed a process for repurposing scrap silicon wafers from its chip manufacturing operations for use in energy-producing solar panels. Through this new reclamation process IBM is now able to more efficiently remove the intellectual property from the wafer surface, making these wafers available either for reuse in internal manufacturing calibration as “monitor wafers” or for sale to the solar cell industry, which must meet a growing demand for the same silicon material to produce photovoltaic cells for solar panels.

“One of the challenges facing the solar industry is a severe shortage of silicon, which threatens to stall its rapid growth. This is why we have turned to reclaimed silicon materials sourced primarily from the semiconductor industry to supply the raw material our company needs to manufacture solar panels,” said said Charles Bai, chief financial officer of ReneSola, one of China’s fastest growing solar energy companies.

IBM and others in the industry use silicon wafers both as the starting material for manufacturing microelectronic products and to monitor and control the myriad of steps in the manufacturing process. According to the Semiconductor Industry Association, worldwide 250 thousand wafers are started per day across the industry. IBM estimates that up to 3.3% of these started wafers are scrapped. In the course of the year, this amounts to approximately three million discarded wafers. Because the wafers contain intellectual property, most can not be sent to outside vendors to reclaim so are crushed and sent to landfills, or melted down and resold.

The new wafer reclamation process produces monitor wafers from scrap product wafers – generating an overall energy savings of up to 90% because repurposing scrap means that IBM 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 - 90% of the energy that they would have needed if they would used a new silicon material source. These estimated energy savings translate into an overall reduction of the carbon footprint – the measure of the total amount of carbon dioxide (CO2) and other greenhouse gases emitted over the full life cycle of a product or service – for both the semiconductor and solar industries.

IBM intends to provide details of the new process to the broader semiconductor manufacturing industry. It is currently in use the Burlington, Vermont facility and in the process of being implemented at IBM's East Fishkill, New York, semiconductor fabrication plant.