SK Group has agreed to hand control of SK Siltron, South Korea's only dedicated semiconductor wafer maker, to Doosan Group for about 2.3 trillion won (US$1.6 billion). The two conglomerates signed the share purchase deal on July 31 after roughly seven months of negotiations, ending a sale process that dragged on longer than anyone expected.
Doosan will pick up a 70.61 percent stake in the wafer business, a position that combines the 51 percent SK Inc. holds directly with another 19.6 percent tied up in total return swap arrangements. SK Group Chairman Chey Tae-won still owns about 29.4 percent of the company, and Doosan says it plans to negotiate separately for those shares, which could take its ownership to 100 percent and make SK Siltron a fully owned subsidiary.
The boards of both companies cleared the transaction the same day, according to a regulatory filing. Doosan was named the preferred bidder back in December 2025, and the original plan was to close in the first half of 2026. That timetable slipped as negotiations got harder — largely because booming AI-related investment kept raising what people thought the wafer business was worth.
What Doosan Is Actually Buying
SK Siltron traces its roots to 1983 and joined the SK group in 2017. It ranks third worldwide in 300-millimeter silicon wafers, the thin discs every modern chip is built on, and it is the only company in Korea producing them at scale. That gives the country a domestic source of the single most important raw material in semiconductor manufacturing.
The deal also comes with a silicon carbide business. SK Siltron expanded into SiC wafers in 2019 when it bought DuPont's SiC division, and those wafers are now central to power electronics for EVs, chargers, and industrial gear. The boards of SK Siltron USA and its affiliates approved liquidation of that US unit on July 16, and Doosan and SK will set up a joint committee to run the wind-down. If the disposal gains beat book value, SK gets a share of the upside tied to its 70.61 percent stake.
There is an earnout structure on top of the base price. Doosan will pay SK 40 percent of any EBITDA above agreed targets between 2027 and 2034, with the bar climbing from 890 billion won in 2027 to 1.7 trillion won by 2034. There is also a customer-qualification clause: if SK Siltron qualifies four designated products with a specific customer by the end of June 2029, Doosan pays an extra 25 billion won per product, or roughly 70.6 billion won if all four land.
Why the earnout? Because both sides knew the price was a moving target. Wafer prices track memory demand, and memory demand has been anything but predictable. Tying part of the payment to future EBITDA lets SK share in the upside if the AI boom keeps running, while Doosan protects itself if the cycle turns. It is a compromise that took months to shape.
Why SK Is Selling
SK has been shedding assets for more than a year as part of a broad restructuring aimed at shoring up its balance sheet and freeing cash for newer bets. The holding company's chip operations have been spending heavily on AI memory, and the group has been pruning businesses it considers non-core. SK said the proceeds from the wafer sale will strengthen its finances and fund future growth initiatives.
The wafer maker had been flagged for sale well before the AI boom peaked. Doosan's December selection followed an evaluation that weighed growth potential, job stability, and other conditions — the kind of checklist a chaebol sale generates when regulators and unions are watching.
Doosan, for its part, has been quietly assembling a semiconductor portfolio. It already owns Doosan Tesna, a chip testing house, and Engion, which specializes in image sensor packaging. Its Electronics BG makes copper-clad laminates used in AI server substrates. SK Siltron plugs a gap at the front of that chain — the material stage — and Doosan says it expects the business to generate around 3 trillion won in revenue by 2031.
The acquisition is big for Doosan, but not reckless: the 2.3 trillion won price equals 6.98 percent of the group's consolidated assets and 18.8 percent of shareholders' equity as of the end of 2025. Doosan plans to fund the purchase with existing cash and borrowings, starting with an immediate deposit of 230 billion won, or 10 percent of the price.
The Bigger Picture for Wafers
The sale lands at a moment when wafer supply has become a strategic talking point across the industry. Chips are the bottleneck for AI servers, and wafers are the bottleneck for chips. Korea's position matters because it hosts the world's two largest memory makers, Samsung and SK Hynix, both of which consume enormous volumes of 300mm wafers every quarter.
Doosan's purchase keeps SK Siltron in Korean hands. That was not guaranteed — foreign buyers circled the business during the sale process, and the perceived value of the asset kept climbing as AI demand extended memory shortages well into 2028. The Samsung Semiconductor profit surge we covered recently is the same demand wave from a different angle, and it is precisely what made SK Siltron harder to price. You can read that story here.
There is also a China dimension. Beijing has been pouring money into domestic wafer and lithography supply, and Chinese wafer makers are expanding capacity even as export controls tighten. A Korean-owned, Korean-run wafer leader is a useful counterweight for chip buyers who want supply options outside China and outside the Taiwan concentration that dominates leading-edge logic. Korea's government has pushed for years to keep critical chip materials inside the country, and a domestic owner for SK Siltron fits that policy directly.
Wafer economics are also shifting under the surface. The industry is moving to larger ingots and thinner slices to squeeze more die out of every boule, and silicon carbide capacity is being added at a furious pace as EV makers lock in supply deals. SK Siltron's mix of legacy silicon and newer SiC exposure puts it in both conversations at once, which is part of why Doosan was willing to pay up.
What Happens Next
Doosan says it will not pursue a separate listing of SK Siltron. Instead it plans an integration task force, possible restructuring, and potentially a merger with its existing semiconductor units to squeeze out cost savings. The remaining 29.39 percent stake talks with Chey Tae-won are the next milestone; those shares are estimated to be worth around 900 billion won on top of the headline price.
The deal is scheduled to close on January 31, 2027, with Doosan paying a 230 billion won deposit immediately and the rest in cash at closing. For a group better known for construction equipment, power plants, and robotics, this is the clearest signal yet that Doosan intends to be a serious name in chips.
Customers will be watching the transition closely. Wafer buyers sign multi-year supply agreements, and a change of ownership always raises questions about pricing, allocation, and who gets priority when capacity is tight. Doosan has said SK Siltron's existing customer relationships will continue, but the real test comes when the next memory upcycle tightens supply again.
Analysts have also flagged the Chey Tae-won stake as the wildcard. If Doosan and the chairman cannot agree on a price for his 29.4 percent, SK Siltron stays a controlled-but-not-wholly-owned business, and the earnout math gets more complicated. Doosan has signaled it wants full ownership, and 900 billion won is the working estimate for what that would take.
For readers tracking the broader chip sector, this deal slots into a pattern: consolidation is accelerating at every layer of the supply chain, from materials to packaging. Read more on South Korea's memory industry and the broader semiconductor sector for context on why wafers have become one of the most contested pieces of the AI supply chain. The original announcement from Yonhap News and coverage from The Elec have the full deal terms.