Recent developments in space technology have created exciting frontiers for the semiconductor industry. From 1973 to 2016, about 160 semiconductor crystals were grown in microgravity onboard Space Lab, the Shuttle and the International Space Station. In fact, the experiments concluded that 86 percent of the space-grown crystals had superior performance attributes compared to their Earth-grown equivalents. They had much larger sizes, better uniformity, and higher performance.
The initial, highly promising results from these experiments have raised enormous interest in using space-grown materials to produce high-performance electronics. Companies, from Space Forge to countless others, are blazing the trail for innovation. Their ForgeStar-1 satellite is purpose-built to grow seed crystals that will one day be used on Earth to manufacture substrates of gallium and aluminum nitride, or silicon carbide. These new materials could greatly increase the efficiency of power devices.
By leveraging the unique conditions of microgravity, researchers believe that the crystal growth process benefits from a “better head start.” Applying uniform temperature and pressure conditions allows for the formation of high-quality crystals. So, we could achieve 20-40 percent increase in switching efficiency over classic Earth-grown semiconductors.
The Advantages of Microgravity
Outstanding growth
Complementary to other facilities, the microgravity environment in space provides unique advantages for crystal growth. As one example, nitrogen can totally disrupt growth processes on Earth. This occurs at moons plume concentrations as low as 10 to the -11 in vacuum chambers. By comparison, space offers a much more pristine environment. The alternate explanation nitrogen is naturally present there at a concentration of roughly 10 to the -22 just above 500 kilometers altitude.
“For example, if you’re worried about nitrogen interfering with your growth process, on Earth [in a vacuum chamber] nitrogen might be present at a concentration of around 10 to the -11,” – Joshua Western
Out in space, the perfect vacuum just makes crystal growth that much better. All this occurs without most of the impurities that poison reactions here on Earth. Joshua Western explains how these environmental factors drastically improve the structural quality of the crystal. These improvements make them better suited to more cutting-edge applications.
That has yet to play out with convincing effects on the production of semiconductor materials in microgravity, some experts remain skeptical. Anne Wilson expressed caution, stating, “I don’t think that microgravity is going to be ideal for the manufacture of bulk materials.” The latter, she said, isn’t where large-scale production gets the most bang for its buck. Making investments in niche materials for very targeted applications likely makes sense.
Economic Viability and Market Potential
Even with the scientific promise of space-grown crystals, economic factors are still a major barrier. Getting everything blasted into space, and then back again for a test is a small fortune. Take SpaceX’s Falcon 9, for instance—it prices roughly $1,500 per kilogram to low Earth orbit. This leads to the critical question of whether the benefits of space-grown crystals can make up for these enormous expenses.
According to new research, the global in-orbit manufacturing market is expected to grow to $28.19 billion by 2034, reflecting a rising demand in this area. Ozark Integrated Circuits specializes in integrated circuits that are ruggedized for aerospace applications. In illustrating the above, they note that declining prices of silicon substrates have made their alternatives relatively more appealing. Matt Francis noted, “While I remember paying $20k a wafer in the early days, we are down in the hundreds of dollars range in volume markets like power.”
This decline in prices has left operators of any space-inflected infrastructure wary of spending on costly crystals grown in microgravity. They are deciding to go the cheaper routes instead. Francis remarked on this trend by stating, “When they were a prized commodity, maybe sending to space made sense. While the cost of space is decreasing, it’s not decreasing faster than the cost of producing wafers.”
The Future of Semiconductor Production
The promise of space-grown semiconductors goes much further than economic benefits. These materials, combined with electrony mobility have the potential to save substantial amounts of energy. In reality, we can get even greater reductions of up to 50 percent in big infrastructure deployments, like 5G pole clusters.
“There is potential for significant energy savings, perhaps as much as 50 percent within large infrastructure installations such as [5G] towers,” – Joshua Western
Furthermore, E. Steve Putna highlighted that space-grown substrates could be transformative for AI data centers where cooling expenses are a critical issue. He emphasized, “if a space-grown substrate increases the yield of a $10,000 high-end AI processor from 50 percent to 90 percent or allows a quantum computer to function closer to room temperature rather than near absolute zero, the launch cost becomes a negligible fraction of the total value created.”
There is a clear excitement for the possibilities space-grown materials can offer. Researchers are aware of challenges that may lie ahead. Joshua Western warned about the degradation that may occur over time: “There will be a level of degradation over time and over generations of growth.”