Diamond Foundry Grows World’s First 200 mm Single-Crystal Diamond in the US

Diamond Foundry announced it has produced the world’s first 200-millimeter single-crystal diamond. The San Francisco-based company revealed the milestone on November 6, calling it the result of a 25-year effort to grow large, continuous diamond crystals.

The new crystal is a single continuous structure rather than a collection of smaller diamonds joined together or a polycrystalline disk. That distinction matters because grain boundaries and defects can disrupt how efficiently heat and electrical charge move through a material. Producing a large single crystal is difficult because manufacturers must maintain a tightly ordered carbon crystal lattice across the entire material as it grows. Even small inconsistencies can introduce defects that ruin the properties engineers want to preserve.

According to CEO Martin Roscheisen, the achievement required advances in plasma physics, reactor engineering, growth chemistry, crystal engineering, and manufacturing controls. He also credited Stefan Gsell and Martin Fischer, whose work on scaling single-crystal diamond started 25 years ago. The company previously announced a 100 mm single-crystal diamond wafer produced using diamond heteroepitaxy, though it has not disclosed if the new 200 mm crystal uses the exact same process.

The semiconductor industry is interested in diamond because of its exceptional thermal conductivity. High-purity single-crystal diamond can conduct heat at roughly 2,000 watts per meter-kelvin at room temperature, which is several times the thermal conductivity of copper. Modern artificial intelligence processors and high-performance computers concentrate heavy electrical power into tight spaces, and localized heat buildup can slow down performance, raise cooling costs, and wear out parts. Diamond could act as a heat spreader or substrate in advanced chip packages to draw heat away from hotspots. Its wide bandgap of about 5.47 electron volts also makes it a strong candidate for high-power and high-frequency electronics that run under harsh electrical conditions.

However, diamond is not yet a simple drop-in replacement for silicon. Manufacturing electronic devices from diamond remains difficult because reliably controlling its electrical properties through doping is challenging. Integrating diamond with existing semiconductor materials and factory processes also needs more development.

The newly unveiled sample is still in its as-grown, unpolished state straight from the growth process. Manufacturers must still achieve consistent thickness, surface flatness, low defect density, and reliable electrical and thermal properties across the usable wafer area before chip manufacturing can begin. They must also prove repeatability across multiple production runs and show that the material can fit into device fabrication.

Diamond Foundry states that the 200 mm breakthrough makes a future 300 mm crystal predictable, though it has not shared a timeline or detailed manufacturing data for that next phase. The company is also expanding its manufacturing goals through a planned $2.77 billion project in Spain supported by the European Chips Act, with the broader aim of turning single-crystal diamond into a mainstream industrial semiconductor material.

Summary

Growing the world's first large single-crystal diamond brings a material with unmatched heat-conducting properties closer to the semiconductor industry. While significant engineering hurdles remain before diamond can replace silicon in computer chips, the milestone opens a potential path to cooling next-generation electronics and high-performance processors.