As tech giants aggressively expand data centers to power cutting-edge AI, these facilities are guzzling electricity at an unprecedented rate. Surprisingly, the majority of this power isn’t even used for computations; it’s lost as waste heat, radiating from the countless transistors packed into every modern computer chip.
According to R. Martin Roscheisen, an electrical engineer and entrepreneur at South San Francisco’s Diamond Foundry (which creates specialized diamonds for electronics), “the chips’ dirty little secret is that over half of all energy is simply wasted as leakage current at the transistor level.”
This excess heat isn’t just wasted energy; it drastically reduces a chip’s lifespan and forces it to operate less efficiently, which in turn creates even more heat. Therefore, a major challenge for data centers is effectively managing server temperatures to ensure smooth and reliable operation.
Roscheisen is among a growing number of engineers exploring the unexpected solution of embedding tiny synthetic diamond fragments directly into computer chips to regulate their temperature. Beyond its famous hardness, diamond boasts an extraordinary ability to conduct heat.
Paul May, a physical chemist at the University of Bristol, highlights that “most people don’t realize diamond possesses the finest heat-conduction properties of any known material.” He explains that diamond transfers heat several times more rapidly than copper, a common component in existing chip heat sinks.
Diamond’s impressive thermal conductivity stems from the very same atomic structure that makes it incredibly tough: each carbon atom is rigidly bonded to four others, forming a robust, interconnected crystal lattice. These strong bonds are remarkably efficient at transmitting the atomic vibrations that constitute heat.
Dr. May predicts a future where “high-end electronics already incorporate diamond heat-spreaders,” and suggests that “within just a few years, even the processors in our personal computers and mobile phones will likely feature diamond-based cooling solutions.”
Recently, Roscheisen’s company has focused on creating ultra-thin, single-crystal diamond layers designed to dissipate heat, which can then be bonded to the reverse side of silicon wafers used in chip manufacturing. While single-crystal diamonds excel at heat transfer compared to multi-crystal arrays, their production is more complex and costly.
The company’s innovative manufacturing process involves creating an intensely hot carbon-rich plasma, then carefully guiding the carbon atoms to deposit in a precise crystalline structure. A crucial technique, they explain, is to “trick” each new diamond into believing it’s growing on an already perfectly aligned diamond layer.
This method essentially provides a blueprint for the incoming carbon atoms. Without such guidance, their website likens the process to “multiple people tiling a floor from different room corners without a template: the pieces would inevitably clash in the middle” instead of forming a single, flawless crystal.
Once these four-inch diamond disks are formed, the company employs patented smoothing techniques to achieve an atomic-level flatness, ensuring no defect exceeds the size of a single atom across the entire wafer surface. This perfectly flat diamond wafer can then be seamlessly integrated onto the underside of silicon chips.
Roscheisen asserts that these diamond layers “completely eliminate chip hotspots,” making them “effectively vanish.”
While Evelyn Wang, a mechanical engineer at M.I.T., acknowledges that “this approach holds the potential to significantly reduce thermal resistance,” she also points out that the technology’s commercial viability is still under evaluation.
Element Six, a De Beers subsidiary, has a long history of producing industrial diamonds, including those for cooling chips in high-power radio communication, like satellite systems. Now, they’re expanding into the computer chip cooling market.
Bruce Bolliger, head of business development at Element Six, notes that “the intense thermal requirements of next-generation AI and high-performance computing are sparking a resurgence of interest in advanced cooling technologies.”
Earlier this year, Element Six unveiled a novel material: a copper-diamond composite. This hybrid aims to outperform pure copper in heat transfer while remaining more affordable than pure diamond. Bolliger states that this “copper-diamond composite offers an optimal thermal management solution” for powerful new chips, potentially enabling faster operation, extended lifespans, and reduced data center cooling expenses.
At Stanford University, electrical engineer Srabanti Chowdhury is leveraging diamond properties to research an entirely new generation of more potent computer chips.
Traditionally, boosting chip speed meant making transistors smaller and packing more onto a single silicon wafer. However, manufacturers are now hitting fundamental physical limits in transistor miniaturization. While layering transistors was explored as a solution, it unfortunately leads to a significant increase in heat generation.
Dr. Chowdhury’s team aimed to tackle heat dissipation using polycrystalline diamond layers, which are simpler to produce than single-crystal ones. Yet, they encountered a challenge: in these multi-crystal layers, the crystals typically align vertically, making them less effective at the crucial horizontal heat transfer required for flat, wide computer chips.
A further complication is that diamond usually requires temperatures exceeding 1,300 degrees Fahrenheit for growth, a heat level far too extreme for the delicate silicon foundation of a chip. When Dr. Chowdhury’s team attempted lower-temperature diamond deposition on silicon, they struggled with proper crystal formation. As she explained, “every crystal accustomed to high-temperature growth faces challenges when grown at lower temperatures.”
This research receives partial funding from DARPA, the U.S. Department of Defense’s research agency. Yogendra Joshi, a mechanical engineer at Georgia Tech and a DARPA program manager, believes that “combining this low-temperature diamond technology with other cooling methods could unlock computing potentials currently beyond our reach.”
Dr. Chowdhury emphasizes that she and her colleagues are confronting a challenge that is both familiar and rapidly escalating. “The issue of heat has always existed, but with the explosive growth of AI, this problem is accelerating like a hockey stick,” she stated. “I haven’t witnessed anything become so critically important so fast.”