A research collaboration between Hong Kong and Mainland China has led to the development of new silicon carbide (SiC) power devices that reduce leakage current by 30-fold. The project, involving Hong Kong's academic sector and Mainland industry, aims to enhance energy efficiency in electric vehicles (EVs) and renewable energy systems, where reducing power losses is critical.

Significant Efficiency Gains in SiC Power Devices

Collaborating with Alpha Power Solutions (APS), Professor Francis Chi Chung Ling from Hong Kong University's research team developed a fabrication process that reduces leakage current in SiC diodes—a key factor contributing to energy loss. The team's approach involved refining aluminum implantation and annealing processes to reduce carbon vacancy defects, which negatively affected device performance.
Alpha Power Solutions (APS), the Mainland industrial partner, has already integrated this process into its production lines, manufacturing over 20 million SiC diodes. The production represents a market value of over HKD 300 million, demonstrating the scalability and economic viability of the new technology.

Economic and Environmental Impacts

The newly developed SiC devices offer improvements in energy efficiency for industries that depend on high-power electronics, such as electric vehicles and power grids. The devices will lower energy losses by reducing leakage current, resulting in cost savings and better performance in power-intensive systems.
This technology will reduce emissions through energy savings, particularly in sectors like renewable energy, where efficiency gains are essential.

Industry Feedback

Alpha Power Solutions acknowledged the research team's contributions in an appreciation letter, noting the successful integration of the new SiC technology into its production processes. With over 20 million SiC devices manufactured using the updated process, APS highlighted the impact on improving production efficiency and expressed optimism about further technological advancements.

Scientific Backing and Collaboration

This project builds on extensive research and international collaboration, including partnerships with institutions like the University of Oslo. The findings from these studies provided the scientific foundation for the new manufacturing process. Key publications include:

• 'Low energy electron irradiation induced deep level defects in 6H-SiC: The implication for the microstructure of the deep levels E1/E2’, X. D. Chen, C. L. Yang, M. Gong, W. K. Ge, S. Fung, C. D. Beling, J. N. Wang, M. K. Lui and C. C. Ling*, Phys. Rev. Lett. 92, 125504 (2004).
• 'Carbon vacancy control in p⁺-n silicon carbide diodes for high voltage bipolar applications', H. M. Ayedh*, K-E. Kvamsdal, V. Bobal, A. Hallén, F.C.C. Ling, and A. Yu. Kuznetsov, J. Phys. D: Appl. Phys. 54, 455106 (2021).
• 'Suppression of the carbon vacancy traps and the corresponding leakage current reduction in 4H-SiC diodes by low-temperature implant activation in combination with oxidation', Tianxiang Lin, Lok-Ping Ho, Andrej Kuznetsov, Ho Nam Lee, Tony Chau, Francis Chi-Chung Ling*, IEEE Electron Device Lett. 44, 578 (2023).
• 'Correlations between reverse biased leakage current, cathodoluminescence intensity and carbon vacancy observed in 4H-SiC junction barrier Schottky diode', Lok Ping Ho, Sihua Li, Tianxiang Lin, Jack Cheung, Tony Chau, Francis CC Ling*, Semicond. Sci. Technol. 38, 115007 (2023).

Looking Ahead: Further Developments in SiC Technology

This research is part of the Guangdong Province's Key-Area Research and Development Program, with a budget of RMB 56 million. The project addressed manufacturing challenges, such as reducing carbon vacancy defects impacting SiC device performance.

Moving forward, the research team focuses on enhancing SiC epi wafers and MOSFET devices in modern power electronics systems. Collaborations with institutions such as the Songshan Lake Materials Laboratory in Dongguan and Huairou National Laboratory in Beijing will further explore advancements in SiC technology to improve device efficiency and reliability in various industrial applications.