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Engineers at IBM’s Burlington, Vermont semiconductor facility have developed and introduced a novel process for pattern removal on wafers that significantly reduces the process costs and environmental waste. The new process is also currently being implemented at IBM's East Fishkill facility.

Traditionally, IBM would strip pattern wafers stripping using corrosive acids such as H2SO4, HF, HNO3, and ozone. The new process avoids the use of corrosive chemicals, removing the pattern using an abrasive pad, water and slurry with the pattern materials coming off as a solid, and is done with fewer physical steps.

The new process allows IBM to select reclaimed wafers for internal reuse as monitor wafers or to sell them on to solar cell manufacturers, who would otherwise have scrapped the silicon. IBM is following many other chip manufacturers in selling scrapped wafers in bulk to solar manufacturers as polysilicon supplies remain tight around the world, and the added attraction of semiconductor grade silicon is that it is of a higher quality than solar silicon.

According to the SIA, worldwide 250,000 wafers are started per day across the industry. IBM estimates that up to 3.3 percent of these started wafers are scrapped. In the course of the year, this amounts to approximately three million discarded wafers.

IBM claims that the new process and reuse program has meant reduced spending on monitor wafers and increased efficiency in IBM's wafer reclaim program. For the IBM Burlington site, the annual savings in 2006 were more than half a million dollars. The projected ongoing annual savings for 2007 is nearly $1.5 million and the one-time savings for reclaiming stockpiled wafers is estimated to be more than $1.5 million.