Diamond Foundry has crossed a major size barrier for synthetic diamond with a 200mm single-crystal diamond—a development that could eventually give chipmakers a powerful new way to move heat away from AI processors.
The company says its D200mm sample is one continuous crystal rather than a collection of fused pieces or a conventional polycrystalline slab. At roughly 7.9 inches across, it matches the diameter of wafers still used in parts of the semiconductor industry, creating a possible path toward manufacturing diamond-based substrates with equipment and processes closer to established chip production.
Diamond is attractive for this job because its thermal conductivity is dramatically higher than copper’s, allowing heat to spread quickly away from concentrated hotspots. It also combines that thermal performance with mechanical strength and electrical insulation. Those properties could make single-crystal diamond useful beneath or alongside high-power processors, where increasingly dense AI hardware is turning cooling into a fundamental design constraint. Diamond Foundry describes the milestone as a step toward manufacturing diamond at semiconductor scale.
The breakthrough is the result of a much longer effort than the company’s 2012 founding date suggests. Diamond-growth specialists Stefan Gsell and Martin Fischer have spent 25 years pursuing larger, higher-quality single crystals, joining Diamond Foundry in 2022 through its acquisition of Augsburg Diamond Technology. The company credits advances in plasma generation, reactor engineering, growth chemistry, process control, metrology and automation for making the new crystal possible. CEO Martin Roscheisen said hundreds of employees contributed to the effort, which involved years of failed experiments and rebuilt equipment.
There is an important distinction between growing a large crystal and delivering a finished wafer to a chip manufacturer. Diamond Foundry’s displayed D200mm specimen is still unpolished, meaning it must undergo additional cutting, flattening, surface treatment and characterization. Yield, defect density, thickness uniformity, cost and compatibility with commercial fabrication processes will determine whether the achievement becomes a practical semiconductor product rather than a materials-science demonstration.
The company is already pointing beyond the current milestone, projecting a possible D300mm single-crystal diamond before the end of the decade. A 300mm format would align with the wafer diameter used by many leading-edge silicon fabs, although that projection remains a manufacturing target rather than a shipping product. Diamond Foundry’s broader portfolio also includes diamond plates intended for direct chip bonding and research into diamond transistors, suggesting the company sees the material as more than an exotic thermal spreader.
Diamond Foundry is entering a field with several competing approaches. Akash Systems is developing GaN-on-diamond and chip-on-diamond technologies that place synthetic diamond beneath computing and radio-frequency devices, while describing diamond cooling as up to five times more thermally effective than copper. Other efforts include diamond-copper composites for AI and high-performance computing hardware. For now, the D200mm crystal is best understood as a promising foundation: the next challenge is proving that wafer-scale diamond can be polished, processed and produced economically enough to cool the machines driving the next generation of computing.
