Researchers at the Korea Electrotechnology Research Institute (KERI) have identified a defect structure that reduces the yield of silicon carbide (SiC) power semiconductors. By analyzing the causes of defects occurring during the power semiconductor manufacturing process, this is expected to be utilized in the development of high-quality production technologies in the future.

The Korea Electrotechnology Research Institute announced on the 22nd that a research team led by Dr. Na Moon-kyung of the Next-Generation Semiconductor Research Center, in collaboration with Chungnam National University and Horiba Estec Korea, has identified the internal structure and origin principles of 'killer defects' in SiC power semiconductors.

SiC power semiconductors are power control semiconductors that operate even in high-temperature and high-voltage environments. In the epitaxy process of manufacturing, if the atomic arrangement is misaligned, stacking defects occur, leading to a problem of low yield.

In particular, 'trapezoidal defects (TZD)' with a length of about 1 mm have been known as major defects that degrade the overall performance of the chip.

The research team investigated the defect structure using multifaceted analysis techniques, including photoluminescence analysis, spectral analysis, atomic-level interpretation, and density functional theory (DFT) calculations.

As a result, it was confirmed that multiple defects consisting of up to 32 layers exist in combination within the trapezoidal defect. In addition, the process by which the defect diffuses into the epitaxial layer during the process and alters the structure was also identified.

The research team explained that this study is significant in that it revealed that a structure previously recognized as a single defect is actually a complex defect structure.

SiC power semiconductors are a material with increasing demand in AI data centers and electric vehicles, and securing manufacturing process stability and yield is considered a critical challenge.

The research results were published in the journal 'Acta Materialia' in the field of metal and inorganic materials.

The research team announced plans to expand defect research to wide bandgap (WBG) semiconductors in general, not just SiC, in the future.

Dr. Na Moon-kyung explained, “We identified the defect structures and change processes that affect power semiconductor performance.”