image: At the center, the violet glow of a GaN semiconductor crystal represents the next-generation in electron beam technology, driving advances in inspection and metrology to improve semiconductor manufacturing yield. Surrounding it are silicon crystals—the very foundation of today’s semiconductor devices. This image symbolizes how GaN brings new possibilities into the silicon-driven world of the industry.
Credit: Photo electron Soul Inc.
NAGOYA, Japan — In late September 2025, KIOXIA Iwate Corporation (Koichiro Shibayama CEO) will begin evaluating a GaN-based e-beam technology developed through joint research between Photo electron Soul Inc. (PeS; Takayuki Suzuki CEO), a Nagoya University startup, and the Amano–Honda Laboratory at Nagoya University.
PeS has developed a next-generation electron gun specialized for GaN (gallium nitride) photocathodes and has demonstrated its effectiveness for semiconductor inspection and metrology (I&M), enabling electron microscopy of nanoscale transistors and high-aspect-ratio structures.
These advances open possibilities for non-contact electrical I&M during the front-end stages of semiconductor manufacturing—previously unattainable with conventional technologies—as well as defect and structural I&M deep inside high-aspect-ratio features, both of which could improve semiconductor manufacturing yield.
KIOXIA Iwate will begin evaluating the technology in its production lines to verify its impact on defect detection, yield improvement, and root cause analysis. This initiative is gaining attention as a model for implementing university-originated technologies and marks a concrete step toward semiconductor manufacturing innovation through collaboration between a university startup and a major corporation.
GaN photocathodes achieve industrial breakthrough
The potential value of photoelectron beam technology from semiconductor photocathodes for semiconductor manufacturing I&M has been recognized for more than a quarter of a century, yet its industrial application has been limited by issues of fragility. To overcome this barrier, researchers at Nagoya University developed GaN photocathodes, achieving more than twenty-fold improvement in durability over conventional technologies and realizing a breakthrough toward electron beam (e-beam) innovation that had been sought after for nearly five decades.
Further advances were achieved by PeS, which developed a type of electron gun specialized for GaN photocathodes. These electron guns demonstrated the lifetimes and uptime stability necessary for semiconductor manufacturing environment, thereby reinforcing the industrial viability of GaN photocathodes. Moreover, PeS has focused on pulsed e-beams and invented Digital Selective e-Beaming (DSeB), a technique that synchronizes e-beam scanning in scanning electron microscopy (SEM)—widely used for semiconductor I&M—with the laser irradiating the photocathode. This innovation enables the delivery of e-beams with controlled intensity to arbitrary pixel-level locations within SEM images, opening new possibilities for selective e-beam irradiation in semiconductor I&M.
An innovative approach to semiconductor inspection and metrology
While process technologies for device miniaturization and 3D integration are well established, I&M technologies began to reach critical limitations without any solutions in sight for solving yield issues. However, PeS has successfully demonstrated the effectiveness of a new I&M approach that addresses the following two challenges in semiconductor manufacturing:
- Electrical I&M of nanoscale transistors: In semiconductor chips consisting of densely integrated nanoscale transistors, it is extremely difficult to perform electrical testing of individual transistors by conventional contact-probing. Using Digital Selective e-Beaming (DSeB), specific regions of nanoscale transistors within memory devices were selectively irradiated with the e-beam. By exploiting electron-beam–induced charging to generate gate bias (non-contact switching), PeS observed this electrical behavior in SEM images.
- I&M of 3D semiconductor devices with high aspect ratios: In advanced devices such as 2.5D and 3D chiplets, high-aspect-ratio trench structures with submicron openings are introduced. This makes it challenging to inspect and measure sidewalls, bottom structures, and defects. For deep observation of high-aspect-ratio silicon trenches, DSeB was used to selectively target the trench bottoms, enabling the detection of residues and visualization of bottom structures.
These achievements open new possibilities not only for non-contact electrical I&M during the front-end stages of semiconductor manufacturing—previously unattainable with conventional technologies—but also for defect and structural I&M in deep high-aspect-ratio regions. Accordingly, this project is expected to provide a novel solution to persistent yield challenges in semiconductor device fabrication.
Significance and outlook
Based on these demonstrations, KIOXIA Iwate will begin evaluating the technology in its production lines with the goal of making it a core technology for future semiconductor manufacturing. The company will conduct detailed evaluations in actual production processes to determine its impact on yield improvement through enhanced defect detection and root cause analysis.
This initiative is also recognized as a model for the societal implementation of university-derived technologies, marking a concrete step toward innovation in semiconductor manufacturing through collaboration between a university startup and a major corporation.