Samsung HBM4 yield hits 80%, pressuring SK Hynix's AI memory dominance

Samsung Electronics' HBM4 yield has climbed to roughly 80 percent, four months ahead of its year-end target, giving the chipmaker the production stability to challenge SK Hynix's AI memory dominance.

Lee Jong-hwan, a professor of system semiconductor engineering at Sangmyung University, said Nvidia and other major customers benefit from multi-vendor sourcing, giving Samsung a window to expand its market presence as HBM4 volumes ramp.

The yield, which stood below 60 percent when mass production began in February, crossed the 80 percent threshold roughly six months later, according to Seoul Economic Daily. Samsung has set a goal of tripling HBM4 revenue in the third quarter from the prior quarter and lifting HBM4 to more than 60 percent of total HBM sales in the second half. The company also aims to raise its HBM market share to near its DRAM share of about 38 percent by year-end.

The yield breakthrough directly supports Nvidia's Vera Rubin AI accelerator production, which depends on high-bandwidth memory supply. Samsung's expanded HBM4 output could also pressure SK Hynix, which has controlled the HBM market since the AI boom began, and give hyperscalers a second reliable source for the memory chips that power large language model training.

"One Team" Approach Drives Yield Gains

Samsung attributed the rapid yield improvement to an integrated strategy in which its memory, foundry, and advanced packaging divisions collaborated from the design phase rather than working in silos. The company also resolved a key technical hurdle in the thermal compression non-conductive film (TC-NCF) process, which had limited yields by affecting how memory dies are stacked and bonded. SK Hynix's own HBM4 yield has also touched 80 percent, according to industry estimates, but Samsung's pace of improvement has narrowed the gap faster than analysts expected.

In semiconductor manufacturing, an 80 percent yield — often called the "golden yield" — means defect rates are low enough that unit costs drop sharply and production can scale without sacrificing quality. Samsung's ability to reach this threshold in six months, versus the roughly year-long timeline typical for advanced memory products, gives it a faster path to profitability on HBM4.

The broader HBM market is tightening as AI infrastructure investment accelerates. AI demand reportedly books nearly all 2027 DRAM and HBM supply from Samsung, SK Hynix, and Micron, according to industry reports, which has driven memory prices higher across the board. Samsung's yield gains come at a moment when supply constraints are the primary constraint on AI accelerator production.

HBM4E Adds Momentum

Samsung's next-generation HBM4E has reportedly crossed 70 percent yield in reliability testing, and the company is expanding capacity at its Hwaseong and Pyeongtaek facilities to meet demand from Nvidia, AMD, and other AI customers. Samsung shipped HBM4E samples in May 2026, positioning the company to compete in the next wave of high-bandwidth memory even as it ramps HBM4 volumes.

The company's 2026 HBM sales could more than triple from 2025 levels, according to Samsung's own guidance, as it uses both existing cleanroom capacity and new fab construction to maximize supply. Samsung's HBM4E mass production timeline has also been accelerated, suggesting the company is betting on a sustained multi-year AI memory cycle rather than a short-term supply squeeze.

Samsung's HBM4 yield milestone and supply expansion could reshape the AI memory market, which has been dominated by SK Hynix. Samsung's semiconductor division stands to benefit from higher HBM4 revenue in the second half, while SK Hynix (000660.KS) faces increased competition as Samsung's HBM market share target of about 38 percent would roughly match its DRAM share. Micron (Nasdaq: MU), which has also reported high-volume HBM4 production for Nvidia's Vera Rubin platform, adds another layer of competition to the market.

This article is for informational purposes only and does not constitute investment advice.