Two Companies Make the Gas That Wires Every Advanced Chip. Both Just Announced They're Shutting Down.
On July 1, 2026, Kanto Denka and Central Glass — the only two Japanese producers of ultra-pure tungsten hexafluoride, the gas chipmakers use to wire together every advanced logic and memory chip — will permanently halt production. The reason: China, which refines roughly 80% of the world's high-purity tungsten powder, cut their raw-material shipments to effectively zero.
The chokepoint, in two supply paths
Simplified model of 2026 WF6 gas supply, based on industry-estimated shares: Japan's high-purity route (~25% of global output) runs entirely on Chinese tungsten powder; the rest of the world's producers (~75%) draw on more diversified feedstock. Numbers are rounded industry estimates, not exact figures. Press the button to see what China's 2026 export tightening actually did to the Japan path.
Both supply paths are flowing normally. Press "Cut Japan's powder supply" to simulate China's 2026 tungsten export tightening.
The plain version
Open up any advanced chip — the AI accelerator in a data center, the processor in your phone — and what you'd find under a microscope looks less like a wafer and more like a 200-story skyscraper of wiring squeezed onto a sliver of silicon. To connect one floor to the next, chipmakers drill millions of microscopic shafts through insulating layers and fill each one with tungsten, a metal that conducts well, doesn't melt during processing, and packs evenly into holes narrower than a virus. You can't pour solid tungsten into a hole that small. Instead, engineers pump in a gas called tungsten hexafluoride (WF6), which reacts and deposits a perfect plug of solid tungsten, one microscopic shaft at a time. In today's 3D memory chips, stacked over 200 layers high, that deposition step repeats for every single layer.
Here's the chokepoint: China refines roughly 80% of the world's ultra-pure tungsten powder, the raw ingredient WF6 is made from. Only two companies on Earth — Japan's Kanto Denka and Central Glass — turn that powder into the highest-grade WF6 that TSMC, Samsung, and SK Hynix actually use in production, together about a quarter of global WF6 supply. Early this year, China tightened tungsten export controls, and powder shipments to those two firms effectively dropped to zero. Both have now told their chip-making customers they're permanently shutting down WF6 production on July 1, 2026. Prices for the gas have already more than doubled.
It's a preview of a pattern AI-chip buyers are learning to watch for: a supply chain doesn't need to lose an entire material to break. It just needs to lose whichever single company happens to make the purest version of it.
Why it matters for tech + supply chain: it's a reminder that a chip's supply chain can bottleneck on a two-company gas plant nobody's heard of — not just on lithography tools or GPU allocations.
The expert version
Interconnect fabrication follows a set sequence: after transistors and an interlayer dielectric are laid down, vias and contacts are etched to the silicon or lower metal layer below, a thin Ti/TiN barrier is deposited to block diffusion and aid adhesion, and the via is filled by chemical vapor deposition — WF6(g) + 3H2(g) → W(s) + 6HF(g), around 300-400°C. The reaction conformally fills nanometer-scale openings at extreme aspect ratios that sputtering can't reach; a CMP step then removes the excess tungsten, isolating each plug. This tungsten-plug process, standard since sub-half-micron CMOS, still dominates the hottest, smallest tier of the interconnect stack — contacts and lower vias — because tungsten's high melting point (3,422°C) and strong electromigration resistance beat copper at that scale. In 3D NAND, where stacks now exceed 200 word-line layers, each layer needs its own tungsten-fill step, so WF6 consumption scales with stack height — one reason memory fabs are especially exposed.
WF6 is made by fluorinating high-purity (6N-grade) tungsten powder, itself refined mostly in China — an estimated 80% of global capacity. Kanto Denka and Central Glass are the only two Japanese suppliers of electronic-grade WF6 at that purity, and both source their powder from China. After Beijing tightened dual-use tungsten export licensing in early 2026, powder shipments to Japan reportedly fell to effectively zero; both firms have told TSMC, Samsung, and SK Hynix they will permanently halt WF6 production on July 1, 2026. Combined, their output is roughly 2,000-2,200 of the 8,000-9,000 metric tons produced worldwide each year — about a quarter of global supply concentrated in two production lines. Spot WF6 prices have risen over 200% since early 2026; exact levels vary by tracker, but the direction and the July 1 shutdown date are well corroborated across industry reporting.
Why it matters for tech + supply chain: it's a reminder that a chip's supply chain can bottleneck on a two-company gas plant nobody's heard of — not just on lithography tools or GPU allocations.