Wacker to expand semiconductor-grade polysilicon cleaning capacity

BURGHAUSEN, Germany—As the demand for semiconductor wafers continues to grow on a global scale, the need for upstream, high-purity, electronic-grade polysilicon metal is increasing along with it.

Wacker Chemie A.G., one of the largest global suppliers of ultra-clean polysilicon metal (as well as silicone monomer, silicone rubbers, fumed silicas and other chemicals), will expand its cleaning line for semiconductor-grade polysilicon in Upper Bavaria by "well over 50 percent," the Munich-based company said June 12.

"As the only European producer of ultra-pure polysilicon, we are proud to be making an important contribution to strengthening Europe's microelectronics supply chain with this project," said Wacker CEO Christian Hartel.

Hartel said the investment is intended to "intensify its focus on polysilicon for applications that demand extremely high quality."

"By expanding our surface-cleaning capacity, we are creating the necessary conditions for meeting the continued fast-growing demand of our semiconductor customers," Hartel said. "We are also able to take the quality of our material to the next level so as to support the semiconductor sector's latest technologies."

The $328 million expansion—expected to come online in 2025—will add 100 jobs in Burghausen, according to Wacker.

Additional jobs are expected to be created via this investment at partner companies, Wacker said.

The infrastructure project also includes the potential for about $50.2 million in research and development funding, pending application approval from the German Ministry for Economic Affairs and Climate Protection.

While capacity expansions for cleaning existing high-purity grades are essential, innovations that solve the needs for even higher-purity polysilicons in the future also is critical.

"As well as expanding capacity, the project includes substantial capital expenditures for research and innovation," Wacker said. "The aim here is to further increase the purity of polysilicon by means of new, highly automated processes, thus enabling semiconductors to meet even smaller design rules and making chips even more powerful."

Wacker applied for funding under the EU's "Important Projects of Common European Interest" program, and received that approval June 8, according to the IPCEI website. This approval funnels Wacker to its next step, which is the pending application filed with the German Ministry of Economic Affairs.

Wacker said in March 2022 that its growth target for electronic-grade polysilicon—including material for solar cells, in addition to semiconductor wafers—is to double its sales by 2030.

Wacker Polysilicons, which has about $107 million earmarked for capital improvements in each of the next several years, saw sales of $2.48 billion in 2022, a 50-percent jump over the $1.66 billion generated in that business segment in 2021.

And that upward trend is expected to increase in 2023, according to Wacker.

A record year in sales for Wacker Chemie A.G. has given the silicone giant the financial strength to increase its capital investments in all business segments—Wacker Polysilicon, Wacker Biosolutions and Wacker Polymers—moving forward, despite an expected slowdown in sales growth in polymers in 2023.

Benefiting from higher selling prices and a positive exchange rate from a strong U.S. dollar, Wacker saw record overall sales of $8.93 billion in 2022, according to official financial results issued in March.

Last year's high mark for the German chemical company compares to $6.74 billion in net sales in 2021, a 32-percent jump. All business units contributed in 2022.

An understanding of the production process for refining silicon metal is important to understanding the capacity imbalance that many believe is looming over three North American manufacturing industries, all of which have crucial roles in quality of life and national defense.

According to the USGS, about 35 percent of silicon metal is refined as a chemical grade that is used for organosilicones and the silicone rubber industry; about 25 percent of refined silicon metal output is used to make polycrystalline (or electronic-grade) silicon for the semiconductor and solar power industries (the markets seeing the highest growth); and about 40 percent of output is a metallurgical grade that is used to make silicon alloy for the metals industry, typically aluminum.

With electronic-grade polysilicon, cleaning the surface of the polysilicon chunks used as a starting material for making semiconductor wafers is "a complex and technically very demanding process," Wacker said.

The cleaning requires strong acids to scrub off the uppermost layer from the surface of the polysilicon.

Using clean room production and packaging facilities, polysilicon cleaning uses cutting-edge automation, Wacker said.

And such high-tech production will be required in the future as electronic-grade polysilicon for microchips and solar arrays continues to require more refined production techniques, as the purity levels required grow higher and higher.

According to Wacker, cleaning polysilicon to an ultra-high purity level requires etching to "ensure the material surface purity."

"With this expansion, we are setting a further benchmark in the purity of polysilicon, making an important contribution to our customers' technology roadmaps," Hartel said.

While Wacker is making these major upstream contributions on the European continent, capacity expansions for refined silicon metal still are needed in North America.

When China's self-imposed brownouts of several major silicon metal refining facilities occurred in 2021, the tenuous nature of global capacity for the essential material fell into stark contrast for silicone rubber processors in North America.

For many, that was the moment when domestic manufacturers of silicone rubber—who depend on a steady stream of high-purity silicon metal—realized the effects of having about 70 percent (about 6 million of the 8.5 million metric tons produced globally in 2021) of the world's refined silicon metal produced at foundries in China.

Only about 5 percent of global capacity is produced in the U.S., a distant fifth behind Russia, Brazil and Norway, according to Portland, Ore.-based Allied Market Research.

Five North American companies, including Canada's Sinova Global, Mississippi Silicon L.L.C. and Ferroglobe P.L.C., accounted for a majority of domestic production.

Dow also refines a portion of its own silicon metal—about 300,000 metric tons per year—through joint ventures with Ferroglobe at two North American locations.

Also looming ominous for the domestic silicone rubber industry is the fact that only one monomer producer remains on U.S. soil: Dow.

Momentive Inc. moved its monomer production to Europe about three years ago.

Along with Wacker, Shin-Etsu Chemical Co. Ltd. in Tokyo and Elkem in Oslo, Norway, import product to the U.S., but supply lines remain a problem.

As one silicone expert put it, the refined silicon industry is "one South China Sea conflict away" from shutting down completely.