Aerospace’s Microelectronics Technology Department Images Space Parts at the Atomic Scale

Zachary Lingley (foreground) and Dr. Brendan Foran work with the scanning transmission electron microscope in the Microelectronics Technology Department’s laboratory. (Photo: Eric Hamburg)

The Microelectronics Technology Department at The Aerospace Corporation is a center for understanding the reliability and physics of the failure of microelectronic and optoelectronic devices used in space systems. The department solves hard problems at the intersection of physics, chemistry, and materials science.

Spacecraft and launch vehicles have numerous onboard microelectronic and optoelectronic components. It is essential that these parts have extremely high reliability, yet components in space systems do fail. These failures can occur from defects in design or workmanship, or because of materials-dependent wear-out related to use conditions, such as thermal cycling and radiation effects.

“Our role is to understand how devices are made, how they are used, and how they fail. This requires understanding materials science, chemistry, physics, and electrical engineering. Our goal is to determine the root cause of failures, provide reliability assessments, and guide improvements, all while trying to minimize the chance of recurrence,” said Maribeth Mason, director of the Microelectronics Technology Department.

The team studies current and future technologies with a variety of testing, modeling and simulation, and analysis techniques to explore device design and fabrication. They test materials, devices, circuits, modules, systems, and packaging. The team also studies materials characterization at the nanoscale.

An atomic resolution, aberration-corrected scanning transmission electron microscope image of a single layer of molybdenum disulfide (MoS2). The Mo atoms appear slightly brighter than the S atoms due to their larger scattering cross section. (Photo: The Aerospace Corporation)

One of the department’s newest pieces of hardware is an aberration corrected scanning transmission electron microscope (STEM) capable of imaging with 70-picometer resolution. This means this microscopy can resolve two small objects (such as atoms) that are 70-picometers apart. The typical atom-to-atom spacing in solids is on the scale of 100 picometers, so this microscope is capable of imaging single atoms. This level of resolution is necessary for seeing how modern microelectronics are made, and for learning how they fail, since modern device performance and reliability are often dependent on structures and interfaces where the ability to see atomic scale defects is critical.

For example, modern silicon-complementary metal-oxide semiconductor (CMOS) integrated circuits rely on gate dielectric layers that can be as thin as 10 atoms, where one defective atom site could play a significant role in allowing dielectric breakdown that would greatly change performance and reliability. “Knowing the quality of manufacturing greatly helps Aerospace assess the risk for use of such modern devices, where changes to operational use of a component could make or break mission success,” said Mason.

“While our department has made good use of TEM in the past, our new TEM has significantly improved resolution at low incident beam energies, and significantly improved detector efficiencies that enable analyses of sensitive materials, as well as offering up to 100 times improved data collection speeds,” said Zachary Lingley, manager, Electronic Materials and Devices Section. “With our new microscope, we can conduct dynamic experiments and look for changes in materials systems as a function of heating and/or electrical bias or current flow,” he added.

The Microelectronics Technology Department routinely uses its instrumentation and capabilities to support a broad range of program efforts across Aerospace’s customer base, from East to West coasts. This includes work supporting Civil Systems Group programs such as those for NASA and NOAA. The team also leads Aerospace Technical Investment Program (ATIP) projects to develop knowledge and capabilities in the areas of reliability for next-generation microelectronics and optoelectronics. The team conducts materials construction analyses and reverse engineering of devices, including on semiconductor integrated circuits, solar cells, laser diodes, ceramic capacitors, imaging sensors, such as charge-coupled devices and focal plane arrays, and a vast number of other types of microelectronic and optoelectronic devices, all of which are critical to Aerospace’s customers’ missions.

—Nancy Profera