Korea Zinc expanded its annual production capacity of ultra-high-purity sulfuric acid for semiconductors from 280,000 tons to 320,000 tons. The company increased capacity in response to growing investment in artificial intelligence (AI) infrastructure and the start-up of new production facilities by domestic semiconductor manufacturers.
Korea Zinc said on the 2nd that it expanded the No. 20 and No. 21 semiconductor sulfuric acid production lines at the Ulsan Onsan Smelter in Ulju-gun, Ulsan, and started full-scale operation. The two lines will add about 40,000 tons of annual production.
Korea Zinc has been gradually expanding its semiconductor sulfuric acid production capacity in line with domestic semiconductor manufacturers' facility investment schedules. The company produced 240,000 tons a year on 17 existing lines, then added the No. 18 and No. 19 lines in 2024 to boost capacity to 280,000 tons. With the start-up of the No. 20 and No. 21 lines this time, capacity increased to 320,000 tons.
Semiconductor sulfuric acid is a material used in the cleaning process to remove organic matter and minute contaminants from wafer surfaces during semiconductor manufacturing. As semiconductor circuits become finer, the allowable level of impurities decreases, and the purity and quality of sulfuric acid affect semiconductor Production yield and reliability. Suppliers must therefore undergo quality approval and process verification by semiconductor manufacturers.
Korea Zinc currently supplies more than 60% of domestic demand for semiconductor sulfuric acid. About 95% of its output goes to major domestic semiconductor manufacturers, and the company also exports to overseas chipmakers in Japan and Singapore.
Korea Zinc recovers and refines sulfur dioxide (SO₂) generated during zinc and lead smelting to produce "six nine (6N)" grade semiconductor sulfuric acid with a purity of 99.9% or higher. Instead of procuring sulfur from outside, the company uses sulfur dioxide generated in the smelting process as a raw material. In Dec. 2024, it received product carbon footprint (PCF) certification for its semiconductor sulfuric acid from Carbon Trust, a U.K. climate change specialist organization.
Korea Zinc plans to gradually increase semiconductor sulfuric acid production capacity to up to 500,000 tons in line with domestic chipmakers' expansion schedules. The company is also reviewing the establishment of a semiconductor sulfuric acid production line with an annual capacity of about 100,000 tons at the integrated smelter in Tennessee, which aims for pilot operation in 2029 and commercial production in 2030.
A Korea Zinc official said, "With this expansion, we will respond in a timely manner to the start-up of new production facilities and output increases at major domestic customers and help stabilize Korea's semiconductor materials supply chain," adding, "Going forward, we will gradually expand domestic capacity in line with customers' demand and investment schedules, and build a semiconductor sulfuric acid supply base in global markets including the United States to establish ourselves as a key partner in the global semiconductor materials supply chain."