High-temperature SiC power semiconductor technology for extreme environments such as aerospace draws attention
SiC power module technology for E-mobility is the focus… Shortened charging time and reliability are essential

Experts have analyzed that SiC power semiconductor technology will be developed in the future to further improve its characteristics beyond the 1200V to 1700V level devices applicable to applications such as electric vehicles, chargers, and solar power.


Kim Hyung-woo, director of the Korea Electrotechnology Research Institute, answered questions that he could not answer due to time constraints during the Mouser Power Seminar session titled “Domestic and International SiC Power Semiconductor Technology Development Trends and Market Status” on May 18.

▲Capture of presentation materials from the 2023 Mouser Power Seminar by Kim Hyung-woo, Director of the Korea Electrotechnology Research Institute

■ What SiC power semiconductor technology is expected to grow and develop significantly in 2023?>

In the case of SiC power semiconductor technology, technology development has been focused on individual devices such as MOSFETs and SBDs, and the ratings of the developed devices have been focused on devices in the 1200 V to 1700 V range that can be applied to applications such as electric vehicles, chargers, and solar power.

The above devices have been developed and commercialized domestically and internationally, and it appears that further technological development will be carried out in the future to further improve their characteristics.

After 2023, R&D is expected to focus on the following: △3300 V – 6500 V SiC discrete power semiconductor devices suitable for high-power applications, △high-temperature SiC power semiconductor technology for extreme environments such as aerospace and geothermal power generation, △high-current SiC power semiconductor device technology for fast charging of electric vehicles, △SiC material-based integrated circuit technology for development of all-SiC module technology, and △SiC power module technology for next-generation E-mobility (electric vehicles, manned drones, etc.).

There are many other technologies, but research and development is expected to focus primarily on the technologies above.

■ What are the important factors to consider and test when optimally applying and utilizing SiC power semiconductors in EVs and charging infrastructure?

The most important things to consider include: △Power level improvement technology to shorten charging time, △Efficiency improvement technology to increase the movable range, △Reliability improvement technology to ensure stability, and △Flexibility technology for V2G applications.

Among the above factors, the technology most in demand in the market is fast charging technology that can shorten the charging time and ensure passenger safety. It is a technology to improve reliability.

Specifically, these include: △DC charging infrastructure for fast charging, △400-800V batteries required for fast chargers, and △improved reliability of components to extend the replacement cycle of chargers.

■ What is the difference between CMOS and bipolar?

CMOS transistors are suitable for applications that require △low-power △high-noise immunity △high-integration density, while bipolar transistors are suitable for applications that require △high-power △high-gain △high-linearity.

However, in the case of SiC, the development of integrated circuit technology based on SiC materials is just beginning, and because the device process using SiC is difficult, there are many difficulties in implementing integrated circuits using CMOS.

Some foreign universities and research institutes are researching digital logic circuits using SiC CMOS and drivers for SiC MOSFETs, but there are still many problems to be solved.

■ What is the difference between the short circuit tolerance of a full SiC module and that of a Si-based power device?

The advantage of SiC material-based power semiconductor devices is that they have higher conductivity compared to Si-based power semiconductor devices.

On the other hand, due to its excellent conductivity, the short-circuit withstand time of SiC material-based power semiconductor devices is very short compared to Si-based power semiconductor devices.

For this reason, short-circuit detection circuits for SiC MOSFETs require fast response speed and high bandwidth.

■ When manufacturing SiC MOSFETs, parasitic diodes are automatically generated like trench MOSFETs.

In the case of SiC MOSFETs, as with Si MOSFETs, a body is formed between the source and drain during device manufacturing. This body diode is also called a parasitic diode or internal diode.