Strain mapping inside an individual processed vertical nanowire transistor using scanning X-ray nanodiffraction

Depiction of the process of nanofocused X-ray beams scattering from a single nanowire transistor. Positively charged particles (+) and negatively charged particles (-) represent charge carriers in a p–n junction (where p–n junction is an interface between p-type and n-type semiconductor materials). Outgoing beams, depicted as white rays, represent scattering from different segments of the device (InAs and GaSb). The bending with arrows represents the strain revealed in the experiment. Illustration by Dmitry Dzhigaev, Lund University.

Thanks to the innovative concept of multi-bend achromats, MAX IV Laboratory has paved the way for fourth-generation synchrotrons. In a new publication, proof is given of the revolutionary impact that MAX IV’s X-rays can have for the advancement of nanoelectronics, both in research and for industrial manufacturers.

A team from Lund University’s Department of Electrical and Information Technology, Department of Physics, and NanoLund, came to MAX IV to study nanowires, and proved that X-ray light from fourth-generation synchrotrons is the key for developing new nanodiffraction and imaging techniques for the characterization of nanostructures.

At the NanoMAX beamline, researchers successfully performed non-destructive observations of nanowires structures for the first time.  “It took us only two days to complete the experiments successfully”, explains Dmitry Dzhigaev, first author of the article. “We could furthermore access length scales that are very difficult to reach with nanofocus beams from previous generation X-ray sources.”

A crucial step in the development of electronics is to assess the quality of the production process. This activity becomes extremely challenging when the electronic components are at the nanometer scale (a billionth of a meter). Currently, nanoelectronics, such as nanowires, must be isolated to be analyzed. “Up to now, we were measuring isolated structures, which do not resemble any practical application. We had no way to understand what happens to the functional parts inside a microprocessor.”

In practical applications, different nanocomponents are assembled in complex architectures, where the interaction between elements, as well as the assembly process, affect the performance of the components. “If you want to create new nanostructures, you must be able to assess how the components interact and behave once assembled. This is something that before fourth-generation X-ray sources could not be achieved without compromising the sample.”

There’s a clear potential for implementing these new analysis techniques in the industrial manufacturing of nanoelectronics. These X-ray techniques open new possibilities for manufacturers to operate a tighter control on the production process and prevent production flaws. “Companies producing nanoelectronics must be able to verify that the final product corresponds to the design. This is particularly important with regards to security.”

Researchers at the Electrical and Information Technology department at Lund University study how to make processors more power efficient. “There are conditions such as space exploration where the amount of energy is limited. By using different elements in different combinations, we can help making processors more energy-efficient.” X-rays beams from MAX IV are a crucial ally, enabling researchers to observe the performance and behavior of fully assembled nanoelectronics without altering the sample.

This new publication is yet another proof of the impact that new generation synchrotrons can have on the future of fields such as material science and technology. MAX IV is truly making the invisible visible.

Strain mapping inside an individual processed vertical nanowire transistor using scanning X-ray nanodiffraction