Light Wavelength of SiC Defects, Long Misidentified for 15 Years, Corrected to 459nm
The light wavelength of defects in silicon carbide (SiC) power semiconductors has been found to be 459nm, not 424nm. The value that had been widely accepted for about 15 years was corrected through atomic-scale analysis. The wavelength indicates the position of the light emitted by a defect, and defects can only be identified accurately if this value is precisely known. Dr. Na Moon-kyung's team at the Next-Generation Semiconductor Research Center of the Korea Electrotechnology Research Institute (KERI) demonstrated this through joint research with a team led by Professor Hong Soon-koo of Chungnam National University, HORIBA STEC Korea, and SK Siltron.
SiC power semiconductors operate stably even under high-temperature and high-voltage conditions, and are widely used in electric vehicles, renewable energy facilities, and power conversion systems. Stacking faults—misalignments in the atomic arrangement that occur during manufacturing—degrade performance, so the ability to accurately detect defects is key.
The research team analyzed more than 100,000 defect data points obtained from 207 commercial wafers. After locating the defects optically, they fabricated specimens at the nanoscale and observed 176 nano-specimens using an atomic-resolution scanning transmission electron microscope. By simultaneously performing density functional theory calculations using a supercomputer to cross-verify the results, they concluded that the actual emission wavelength is 459nm. The study directly linked emission characteristics to actual atomic arrangements, revealing an error in the conventional defect identification information.
The research findings were published in Acta Materialia, a leading international journal in materials science. The manuscript was accepted for publication without any revision requests from reviewers.
In recognition of this achievement, Principal Researcher Na Moon-kyung received an encouragement award at the '2026 Horiba Masao Award,' hosted by Japan's HORIBA. It is the first time since the award was established in 2004 that a researcher from a Korean research institution has won it. "The significance lies in directly linking the optical signal to the actual atomic structure and correcting an identification standard that had been accepted for so long," said Na. "Going forward, we will continue to advance our analytical technology to help enhance the quality competitiveness of the domestic power semiconductor industry."
This research was supported by the Ministry of Trade, Industry and Energy's 'Compound Power Semiconductor Advancement Technology Development Project.'
