Diamond Foundry Grows 200mm Single-Crystal Diamond
The company revealed a continuous diamond disc matching the 200mm silicon wafer size used in many power and analog chips.
Updated on Nov. 8, 2026 in Semiconductors
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Diamond Foundry has grown the first single-crystal diamond measuring 200mm across, shown as grown and unpolished. CEO Martin Roscheisen revealed the crystal in a video keynote at the CarbonSemi 2026 conference in Ningbo, China.
Why it matters
Diamond conducts heat at roughly 2,000 W/mK, about five times better than copper, making it a candidate for cooling high-power chips. Chip plants are built around 200mm and 300mm wafers, so a substrate of matching size could fit more readily into existing production lines.
The disc is one continuous crystal rather than tiled or polycrystalline pieces, and diamond's bandgap of about 5.5 eV compares with 1.1 eV for silicon and roughly 3.3 eV for silicon carbide. Diamond Foundry has not disclosed yield, defect density, or per-wafer cost for the 200mm crystal.
The players
Diamond Foundry
A San Francisco-based company producing lab-grown single-crystal diamond for semiconductor and industrial applications.
Martin Roscheisen
The chief executive of Diamond Foundry who revealed the crystal during a video keynote at CarbonSemi 2026.
The details
Diamond Foundry credits advances in plasma physics, reactor design, and process control for the growth. Scientists Stefan Gsell and Martin Fischer joined the company in 2022 through its acquisition of Augsburg Diamond Technology, and the company says its work reflects about 25 years of experience scaling single-crystal diamond.
Timeline
November 5, 2026: Diamond Foundry announced the 200mm single-crystal diamond.
November 6, 2026: The company issued a press release and website post on the crystal.
The Tech Race
The effort to use diamond in chips follows years of research into wide-bandgap materials such as silicon carbide, which are already used in power electronics. Diamond's far higher thermal conductivity and bandgap position it as a potential successor if its wafers can be produced at volume and cost.
For now, the crystal does not change what chips people can buy, since the company has not released a commercial timeline or yield data. Any eventual benefit to devices would depend on finished 200mm wafers reaching production at a workable cost.
The takeaway
The 200mm crystal is a meaningful demonstration of size, but the next proof point is finished wafers with published quality and cost data. Readers should watch for those figures before assuming diamond substrates are close to real products.
Further reading
Explore more on Semiconductors to see how new substrate materials are reshaping chip manufacturing.
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