Ultrafast SEM Enables Functional Characterization of Devices

Researchers from the University of Tsukuba combined a femtosecond laser and a scanning electron microscope to create an ultrafast time-resolved scanning electron microscopy device. This novel system makes it easier to observe different materials’ instantaneous states. The study has been published in the journal ACS Photonics.

Modern society depends on electronic devices, whose rapid advancement necessitates ever-faster operating speeds. The next generation of technologies, referred to as Beyond 5G, is the focus of ongoing research and development efforts. These technologies outperform the fastest 5G band available today.

Precise measurement of high-speed phenomena like electric potential and electron transfer within the devices is essential to comprehending their operation and facilitating the development of these ultrafast semiconductor devices.

To measure possible changes in device materials with high temporal resolution, the research team combined a femtosecond (10⁻¹⁵ second) laser with a scanning electron microscope.

The team obtained 43 picosecond-resolution SEM images using this instrument to conduct scanning electron microscopy (SEM) of a photoconductive antenna device on a GaAs substrate.

These results allow electrical circuit performance to be measured over a bandwidth of 23 GHz, which is above and beyond the frequencies commonly used in 5G communications.

This innovative technology allows for the high-speed, non-contact, three-dimensional measurement of changes in dynamic potential at any point within device structures. It is expected to play a vital role in the creation of next-generation electronic devices.

Journal Reference:

Arashida, Y., et al. (2024) Visualizing the Transient Response of Local Potentials on Photoconductive Antennas Using Scanning Ultrafast Electron Microscopy. ACS Photonics. doi.org/10.1021/acsphotonics.3c01532