German silicones manufacturer Wacker Chemie AG has recently finished expanding its production of hyperpure hydrogen chloride at its Burghausen site in Germany. The facility which was commissioned in mid-July significantly increased overall production. Buyers for the newly added production volumes come from the semiconductor industry, which uses ultrapure hydrogen chloride as an etching and cleaning agent. Investment costs for the new plant are in the low double digit million euros range. The increase in capacity will strengthen the company’s specialty chemicals portfolio for the semiconductor industry, it adds.
Hydrogen chloride (HCl) has many different applications in the chemical industry. Use of this reaction gas allows manufacturers to turn low-energy raw materials into reactive intermediates for down-stream production steps. Wacker, for instance, uses HCl for manufacturing silicones, pyrogenic silica and polysilicon for the solar and semiconductor industries.
The colourless, water-soluble gas is also an important processing aid for the semiconductor industry. Hydrogen chloride is used for etching hyperpure silicon wafers and for cleaning plant components. However, the media used must be extremely pure to prevent contamination.
“A lot of our competitors have dropped out of hydrogen chloride production in recent years for reasons of cost and quality. That, along with growing demand for semiconductor components, has made ultrapure HCl difficult to come by right now,” says Wacker Executive Board member Christian Kirsten.
Wacker says it is currently one of the very few companies in Europe that is able to deliver HCl in the quality and quantities needed. The company initiated investments in the low tens of millions of euros to cover the recently completed expansion work and associated infrastructure at its Burghausen site.
Wacker adds it manufactures hydrogen chloride using rock salt from its own mine in Stetten, Germany. The composition and purity of the salt mined there is especially suitable for production.
“Up to now, 99.9979 percent purity was the benchmark for HCl suitable for semiconductors,” says Thomas Koini, president of the Wacker Silicones business division. “Our hydrogen chloride is 99.9995 percent pure, which makes it much purer than most of what is available. That’s also going to meet the quality and purity requirements of the chip industry in the future.”
In addition to hydrogen chloride, the chemical group also produces other specialty chemicals for the semiconductor industry. Examples from its product portfolio include precursors for coating hyperpure silicon wafers as well as pyrogenic silica, which is used as a grinding agent for CMP slurries.
Key buyers for these kinds of products are international gas suppliers that sell processing aids and other specialty chemicals to semiconductor companies.