Diamond Foundry unveils world’s first 200mm single-crystal diamond wafer

The San Francisco company doubled its 2023 record and is pitching lab-grown diamond as a cooling fix for AI chips Diamond Foundry has grown a single-crystal diamond measuring 200 mm across, the first at that scale. The San Francisco company showed it off on November 5-6, 2026, at the CarbonSemi 2026 conference in Ningbo, China. The pitch has nothing to do with engagement rings. Diamond Foundry wants this material sitting underneath AI chips, pulling heat away from processors that keep getting hotter. A bigger diamond, with a specific job The company calls the new crystal D200mm. It doubles the diameter of the 100 mm single-crystal wafer Diamond Foundry announced in November 2023. The key word is “single-crystal.” The D200mm has one continuous crystal structure. That separates it from polycrystalline diamond, which is built from many smaller crystals fused together. That continuity is what makes the crystal a potential semiconductor substrate, meaning the base layer that chips are built on or bonded to. Grain boundaries in polycrystalline material can interfere with both heat flow and electrical behavior. The diamond on display is still unpolished. A raw crystal and a finished, fab-...