Michigan researchers create ultrathin ferroelectric semiconductor for next-generation computing: 'This will be very important'

A team of researchers at the University of Michigan has developed an ultrathin ferroelectric semiconductor, measuring just 5 nanometers thick, with the potential to revolutionize computing and power next-generation technologies.

Ferroelectric semiconductors offer unique capabilities such as sustaining electrical polarization and can be used for sensing, energy harvesting and storage, the university said in a release.

The breakthrough opens doors for integrating ferroelectric technologies into mainstream devices like computers and smartphones, enabling advancements in artificial intelligence, Internet of Things (IoT) and battery-less devices, the release said. The study, published in Applied Physics Letters, has been recognized as an editor's pick and demonstrates the potential for highly efficient and low-power integrated devices in the future.

Ferroelectric semiconductors have emerged as promising contenders to bridge the gap between mainstream computing and next-generation architectures. The 5-nanometer measurement corresponds to a span of around 50 atoms.

”This will allow the realization of ultra-efficient, ultra-low-power, fully integrated devices with mainstream semiconductors,” Zetian Mi, a professor of electrical and computer engineering at the University of Michigan and co-corresponding author of the study, said in the article as he emphasized the significance of the achievement. “This will be very important for future AI and IoT-related devices."

What sets ferroelectric semiconductors apart from others, the article said, is their ability to sustain electrical polarization, similar to the electric version of magnetism. Unlike a typical magnet, they can switch between positive and negative poles. This unique property finds various applications, including light and acoustic sensing, as well as energy harvesting. The ability to harvest ambient energy is particularly exciting since these ferroelectric devices can become self-powered.

Furthermore, ferroelectric semiconductors offer an alternative approach to storing and processing both classical and quantum information. The two electrical polarization states can serve as the basis for computing, where they represent the binary values of one and zero.

This computing paradigm also emulates the neural connections in the human brain, enabling memory storage and information processing simultaneously, the release said. Known as neuromorphic computing, this architecture is ideal for supporting AI algorithms that rely on neural networks to process information.

One notable advantage of storing energy as electrical polarization is its lower energy consumption compared to capacitors in random access memory (RAM). Traditional capacitors constantly draw power to maintain stored data, whereas ferroelectric memory can endure and outlast solid-state drives (SSDs). Moreover, this type of memory can be packed more densely, increasing its storage capacity, while also exhibiting enhanced robustness against harsh environmental conditions, including extreme temperatures, humidity and radiation. In a previous study, the team of researchers demonstrated ferroelectric behavior in a semiconductor composed of aluminum nitride doped with scandium, a metal commonly used to reinforce aluminum in high-performance bicycles and fighter jets. However, to integrate this technology into modern computing devices, they needed to manufacture films with a thickness below 10 nanometers, equivalent to about 100 atoms.

Using molecular beam epitaxy, a technique commonly employed in the production of semiconductor crystals for devices like CD and DVD players, the researchers successfully deposited a crystal with a thickness of 5 nanometers—marking a new record in scale reduction. This achievement was made possible by precisely controlling each atomic layer in the ferroelectric semiconductor and minimizing atom losses from the surface.

Ding Wang, a research scientist in electrical and computer engineering and the first author of the study, highlighted the implications of reducing the thickness. "By reducing the thickness, we showed that there is a high possibility that we can reduce the operation voltage,” Wang said. “This means we can reduce the size of the devices and reduce the power consumption during operation.”

Additionally, the nanoscale manufacturing process improves the researchers' ability to study the fundamental properties of the material, explore its performance limits at small sizes and potentially pave the way for its use in quantum technologies due to its unique optical and acoustic properties. Ping Wang, a research scientist in electrical and computer engineering at the University of Michigan, emphasizes the significance of the thinness: "With this thinness, we can really explore the minuscule physics interactions. This will help us to develop future quantum systems and quantum devices." The research conducted by the team at the University of Michigan was supported by the Defense Advanced Research Projects Agency (DARPA). The studies were performed in the Lurie Nanofabrication Facility and Michigan Center for Materials Characterization, enabling the advancement of nanoscale research and innovation.