News | Apr 1, 2019
US Air Force builds first-of-its-kind lab for growing gallium oxide crystals, semiconductors
Industry partners can leverage unique manufacturing capabilities through cooperative research or patent licensing
WRIGHT-PATTERSON AIR FORCE BASE, Ohio – The Air Force Research Laboratory has a new laboratory for growing special crystals needed for innovative electronics.
The Oxide Molecular Beam Epitaxy laboratory is poised to become a major developer of high-quality semiconductor materials used in a new breed of lighter, smaller, more powerful electronics.
At the center of the laboratory is the MBE chamber, a first-of-its-kind capability within the United States. This highly-specialized piece of equipment enables the growth of semiconducting materials that can be used for specialized power electronics that are common in today’s modern aircraft, as well as many consumer electronics.
“This is the first system of this kind specifically designed to grow gallium oxide, which is a promising new material for high-performance electronics,” said Dr. Don Dorsey, a materials research engineer at the lab.
Dorsey said that gallium oxide is emerging as an electronics material, but much remains to be learned about its properties and performance. Unlike commonly-used silicon-based semiconductors, gallium oxide can handle much higher operating voltages.
Current components in aircraft, like the side-looking airborne radar that is mounted to the belly of E-8 Joint STARS, which are necessarily large, could be made much smaller and lighter. Dorsey likens this to eliminating a laptop’s voltage converter.
“A simple example is the power adaptor located on the cords of laptop computers. We think the promise of this is that you could get rid of that entirely and have a small component on the circuit board that would do the same job,” Dorsey said.
What makes the Air Force’s Oxide MBE Laboratory ideal for this type of materials research is that it is specifically and solely designed for the growth of gallium oxide.
Dorsey said eliminating contamination is critical for growing quality crystals. Since the new MBE chamber will only be used for gallium oxide, there is no chance of cross-contamination.
“This unique piece of equipment gives us an advantage,” said Dorsey. “We are able to produce extremely pure samples and have the assurance that our material formulations are exactly as we intend them.”
The MBE capability enables AFRL materials experts not only to produce high-quality semiconducting materials but to further refine their production capabilities through a synergistic relationship with the lab’s sensors researchers, who incorporate the materials into their electronic components.
The sensor experts then provide feedback to the materials team, who use that information to adjust the material growth in the MBE chamber. This back-and-forth process is helping the team to learn more about the formulations that produce the best quality semiconductors for application-specific purposes.
Private companies can partner with the Air Force and access its specialized equipment through TechLink, the Department of Defense’s national partnership intermediary for technology transfer.
In 2018, Air Force researcher Eric Heller developed a new technology that confines electrons as they traverse high-power gallium oxide enabled semiconductors. And in January, the Air Force’s gallium nitride semiconductor technology was publicly disclosed in a U.S. patent application. Manufacturing the semiconductor’s special layers requires molecular beam epitaxy.
The patent-pending technologies are available for license to U.S. businesses that would use them in new products and services. And licensing inquires can be sent to TechLink.
- Electron carrier confinement in gallium oxide
- Growth of nitride semiconductors on thin Van der Waals buffers for mechanical lift off and transfer
Dr. Shin Mou, a materials researcher the MBE Laboratory, said the new capabilities bridge the gap between university and industry research efforts.
“The capability to produce up to four-inch wafers enables us to work with university Centers of Excellence as well as industrial research organizations to advance the material capabilities and open new doors for this technology,” he said.
Mou said that the long term goals for this work include refining the material to the point that it can be transferred to U.S. industry for large-scale production. Having a domestic supply chain for advanced semiconductors would ensure widespread, low-cost availability of these materials for both military and commercial use.
This story was adapted from reporting by Holly Jordan, Air Force Research Laboratory.