The memory devices fabricated using tantalum oxide on this chip can store data for both conventional memory and in-memory computing above 1000°F. (Photo credit: Brenda Ahearn, Michigan Engineering)
New tech could open doors to using computers in environments with extreme heat, like Venus.
ANN ARBOR, Mich. — Scientists have developed a groundbreaking computer memory device that can operate at temperatures over 1100°F (600°C) – hot enough to withstand the blazing conditions inside jet engines, geothermal wells, and even on the surface of Venus. This breakthrough could help overcome one of the most fundamental limitations of modern electronics: their inability to function at very high temperatures.
Contemporary electronics are built on silicon semiconductors, which start to fail at temperatures above 150°C (302°F). When heated above this temperature, these semiconductors begin conducting uncontrollable levels of current. Since electronics are precisely manufactured to operate at specific current levels, this heat-induced current can wipe information from a device’s memory. This temperature limit has prevented the use of sophisticated electronics in environments like aerospace engines (150°C-600°C), Venus exploration missions (550°C), and deep geothermal wells (300°C-600°C).
A research team led by scientists from the University of Michigan, in collaboration with Sandia National Laboratory, has now shattered this thermal barrier. Their device, detailed in a recent paper published in the journal Device, operates through an electrochemical process similar to a battery, but instead of storing energy, it stores information. The system uses a solid electrolyte barrier that allows only oxygen ions to move between layers while blocking other charged particles.
“It could enable electronic devices that didn’t exist for high-temperature applications before,” says Yiyang Li, assistant professor of materials science and engineering at the University of Michigan and the study’s senior corresponding author, in a statement.
Yiyang Li, an assistant professor of materials science and engineering at UM, and Sang Yong Lee, a doctoral student of materials science and engineering in Li’s lab, are preparing to measure the temperature tolerance of the memory device. (Photo credit: Brenda Ahearn, Michigan Engineering)
The device’s architecture consists of three main layers: a semiconductor made of tantalum oxide, a metal layer of tantalum, and a solid electrolyte called yttria-stabilized zirconia (YSZ) sandwiched between them. Three platinum electrodes control the movement of oxygen ions through this structure. Unlike the electrons in conventional memory, these oxygen ions remain stable even at extreme temperatures.
When oxygen atoms leave the tantalum oxide layer, they create a region of metallic tantalum. Simultaneously, a tantalum oxide layer forms on the opposite side of the barrier. These layers maintain their separation, much like oil and water, ensuring the stored information remains stable until deliberately changed by applying a new voltage. By controlling the oxygen content, the researchers can change how easily electrical current flows through the material, creating different states that represent stored information.
The researchers demonstrated their device’s remarkable durability through rigorous testing. It could switch between different states more than 10,000 times without failing and maintained its stored information for at least 24 hours at both 400°C (752°F) and 600°C (1,112°F). Currently, the device can store one bit of information, but Li notes that “with more development and investment, it could in theory hold megabytes or gigabytes of data.”
With the device secured in the heater, the researchers will be able to test how well it works at extreme temperatures. (Photo credit: Brenda Ahearn, Michigan Engineering)
The system does have one significant limitation: new information can only be written to the device at temperatures above 250°C (500°F). However, the researchers suggest this constraint could be overcome by incorporating a heater for devices that need to operate at lower temperatures.
Beyond just storing binary information (ones and zeros), the device can maintain multiple intermediate states, making it capable of analog storage. This capability could be particularly valuable for artificial intelligence applications in extreme environments, where processing power and energy efficiency are crucial concerns.
“There’s a lot of interest in using AI to improve monitoring in these extreme settings, but they require beefy processor chips that run on a lot of power, and a lot of these extreme settings also have strict power budgets,” explained Alec Talin, a senior scientist at Sandia National Laboratories and study co-author. “In-memory computing chips could help process some of that data before it reaches the AI chips and reduce the device’s overall power use.”
While other high-temperature memory technologies exist, this new device offers distinct advantages: it operates at lower voltages than alternatives like ferroelectric memory and polycrystalline platinum electrode nanogaps, while providing more analog states for in-memory computing. The device can maintain its information states above 1100°F for more than 24 hours, matching the temperature performance of the best existing technologies while offering these additional benefits.
The ceramic heater glows red when brought to high temperatures. (Photo credit: Brenda Ahearn, Michigan Engineering)
The researchers have already filed a patent and are seeking partners to bring the technology to market. This advancement could enable new generations of electronics capable of operating in environments that were previously off-limits to sophisticated computer systems, from the depths of geothermal wells to the surface of other planets.
Paper Summary
Methodology
The researchers created their device by carefully layering different materials using a technique called sputtering, which involves shooting atoms at a surface to build up thin films. They started with a silicon base, added various layers including tantalum oxide, yttria-stabilized zirconia (YSZ), and platinum electrodes, and protected everything with a silicon nitride coating. They tested the device’s performance using specialized probe stations in an argon atmosphere with very low oxygen content, carefully controlling temperature and electrical conditions throughout their experiments.
Results
The device demonstrated several key achievements: it could switch between states reliably at temperatures up to 600°C, maintained stored information for at least 24 hours at these extreme temperatures, showed consistent performance over more than 10,000 switching cycles, and could store multiple analog states. The team verified the phase separation mechanism using transmission electron microscopy, providing direct visual evidence of how the device maintains stability at high temperatures.
Limitations
The current device requires temperatures above 250°C to write information effectively, making it impractical for room-temperature applications without additional heating elements. The prototype is also relatively large compared to modern computer memory, and would need significant miniaturization for practical applications. Additionally, the protective coating used isn’t sufficient for operation in oxidizing environments, meaning additional protection would be needed for many real-world applications.
Discussion and Takeaways
This research represents a significant advance in high-temperature electronics, demonstrating performance far beyond the capabilities of conventional silicon-based devices. The use of phase separation as a stability mechanism is particularly innovative and could inspire new approaches to creating heat-resistant electronics. The device’s ability to store analog values also makes it potentially valuable for specialized computing applications, particularly in artificial intelligence systems operating in extreme environments.
Funding and Disclosures
The research was primarily supported by the National Science Foundation and a Sandia University Partnership Network program. Work was conducted at various University of Michigan facilities, including the Lurie Nanofabrication Facility and the Michigan Center for Materials Characterization. The authors have filed a patent based on this work with the US Patent and Trademark Office.