A significant upgrade at Cornell University aims to enhance research capabilities in nitride semiconductors, pivotal materials for technologies such as LEDs and 5G communications. The newly installed metal-organic chemical vapor deposition (MOCVD) system in Duffield Hall will enable researchers to explore next-generation materials, including those that support quantum computing and advanced radiofrequency devices.
The MOCVD system functions by injecting vapors of custom-designed chemicals onto a heated substrate, facilitating a process known as epitaxial growth. This method allows for the creation of ultra-thin crystalline layers with atomic-level precision. Traditionally, MOCVD has been instrumental in developing common nitride semiconductors, including gallium nitride, aluminum nitride, and indium nitride, which have revolutionized energy-efficient lighting and high-frequency electronics.
Researchers at Cornell, led by Hari Nair, assistant professor of materials science and engineering, are now looking to expand the functionalities of nitride materials. “The established family of nitrides do a fantastic job, but now we are at a point where we can move on to other nitrides, like niobium nitride, which is a superconductor,” Nair stated. This new exploration could lead to advancements in high-coherence microwave qubits and next-generation quantum communication systems.
One of the system’s innovative capabilities includes the potential replacement of conventional aluminum-aluminum oxide Josephson junctions, essential components of quantum computers, with all-epitaxial nitride versions. Another promising research trajectory involves modifying aluminum nitride to exhibit ferroelectric properties by incorporating small amounts of scandium, a trend gaining traction in both academic and industrial sectors.
Many of these advanced nitrides have primarily been produced using molecular beam epitaxy, a method useful for laboratory research but not easily scalable for industrial applications. In contrast, MOCVD is already widely used in commercial production of LEDs and gallium nitride-based power devices, making it a crucial tool for translating research into practical applications.
“Every single LED that’s commercially made uses MOCVD,” Nair emphasized. “If we can develop growth processes for these new nitrides using MOCVD, they’ll be much easier to translate into industry. That’s what makes this so exciting – it’s not just about what we can study in the lab, it’s about how we can scale it.”
The Cornell team collaborated with AIXTRON to design this unique MOCVD system, specifically tailored to address the challenges of growing new nitride materials. This is the first system in the United States configured from the outset for the purpose of cultivating both new and established nitrides. It features dual metal-organic delivery channels—one for traditional precursors and another for low vapor pressure precursors, such as scandium and niobium. Moreover, a triple-plenum showerhead ensures that these precursors do not mix until they enter the reactor, enhancing the precision of the growth process.
Nair remarked, “When we talk about a materials science breakthrough, it’s many evolutionary steps that build up. This system is one of those steps. It gives us the platform to explore, discover and ultimately help drive a new era in materials for electronics, optoelectronics and quantum information systems.”
The MOCVD system aligns with national priorities, supporting various research initiatives funded by the U.S. Department of Defense. This upgrade was made possible through a grant from the Department of Defense, championed by Kenneth Goretta, a retired program manager at the U.S. Air Force Office of Aerospace Research and Development.
Furthermore, Cornell researchers expect that this system will bolster technologies being developed by Soctera, a Cornell-based startup focused on millimeter-wave power amplifiers utilizing high-quality aluminum nitride. Soctera’s innovations are aimed at defense applications, including advanced radar systems, autonomous vehicle communications, and satellite networks.
As Cornell embarks on this new journey in nitride research, the implications for future technologies are vast, potentially transforming fields such as quantum computing and high-frequency electronics.
