Diamond Foundry presents 200-mm single-crystal diamond

Diamond Foundry presented a 200-mm single-crystal diamond on November 5, 2026, at CarbonSemi 2026 in Ningbo, China. CEO Martin Roscheisen presented the material, which consists of one continuous crystal rather than a polycrystalline structure or multiple joined pieces. The 200-mm diameter matches the 8-inch wafer format used in the semiconductor industry.

Image: Igor's Lab

The company says the material could help cool AI accelerators by acting as a heat spreader. It would distribute heat over a larger area to manage hotspot peaks, though it would not replace existing cooling systems like liquid cooling or heatsinks.

The presented diamond is an unpolished crystal and is not currently a substrate qualified for mass production. The business has not published metrics concerning manufacturing output, structural flaws, or expenses. The company has also not announced a date for commercial mass production or specific customer qualifications. While the company suggests 300-mm crystals may be possible in the future, this remains a technical assessment.