Successful visualization of instantaneous states of materials in high-speed devices: novel scanning electron microscopy technique

Tsukuba, Japan—The rapid advancement of electronic devices, which underpins modern society, demands increasingly faster operating speeds. Active research and development efforts are directed towards the next generation of technologies that surpass today's fastest 5G band, known as Beyond 5G. To facilitate the development of these ultrafast semiconductor devices, precise measurement of high-speed phenomena such as electric potential and electron transfer within the devices is crucial for understanding their operation.

To tackle this challenge, the research group combined a scanning electron microscope with a femtosecond (10 ⁻¹⁵ second) laser to measure potential changes in device materials with high temporal resolution. They used this instrument for performing scanning electron microscopy (SEM) of a photoconductive antenna device on a GaAs substrate and obtained SEM images with a resolution of 43 picoseconds. These findings enable the measurement of electrical circuit performance across a bandwidth of 23 GHz, which exceeds the frequencies typically used in 5G communications.

This breakthrough technology offers non-contact, high-speed, three-dimensional measurement of dynamic potential changes at arbitrary points within device structures. It is anticipated to be a vital tool in the development of next-generation electronic devices.

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The corresponding authors and a part of the co-authors were supported by the Innovative Science and Technology Initiative for Security, ATLA, Japan (JPJ004596). This work was partly supported by the grant-in-aid for JSPS KAKENHI (19H00847 and 22H00289).

Title of original paper:
Visualizing the transient response of local potentials on photoconductive antennas using scanning ultrafast electron microscopy

Journal:
ACS photonics

DOI:
10.1021/acsphotonics.3c01532

Professor FUJITA, Jun-ichi
Assistant Professor ARASHIDA, Yusuke
Institute of Pure and Applied Sciences, University of Tsukuba

Institute of Pure and Applied Sciences

ACS Photonics

10.1021/acsphotonics.3c01532

Visualizing the Transient Response of Local Potentials on Photoconductive Antennas Using Scanning Ultrafast Electron Microscopy

8-May-2024