In recent years, the appearance of SiC power devices has greatly improved the performance of semiconductor devices, which is of great significance to the development of the power electronics industry. According to Yole's forecast, the SiC power device market is expected to reach 1.4 billion U.S. dollars by 2023, and its main market growth opportunities are in the automotive field, especially in the electric vehicle application market such as EVs, hybrid vehicles and fuel cell vehicles.

Compared with Si devices, SiC power devices can effectively achieve high efficiency, miniaturization and light weight of power electronic systems. It is understood that the energy loss of SiC power devices is only 50% of Si devices, the heat generation is only 50% of Si devices, and there is a higher current density. Under the same power level, the volume of the SiC power module is significantly smaller than that of the Si power module. Taking the smart power module IPM as an example, using SiC power devices, the module volume can be reduced to 1/3 to 2/3 of the Si power module.

At present, more and more manufacturers are increasing investment in silicon carbide (SiC) devices. Well-known foreign manufacturers include ROHM, Bombardier, Cree, SDK, STMicroelectronics, Infineon Technologies, Littelfuse, Ascatron, etc., and many domestic manufacturers have successively launched SiC power device products. , Such as Tyco Tianrun, Basic Semiconductor, Shanghai Zhanxin Electronics, Yangjie Technology, Xinguang Runze, Ruineng Semiconductor and so on.

Recent developments in SiC power semiconductor device technology

1, SiC power diode

There are 3 types of SiC power diodes: Schottky diodes (SBD), PIN diodes and junction barrier control Schottky diodes (JBS). Due to the Schottky barrier, SBD has a lower junction barrier height. Therefore, SBD has the advantage of low forward voltage. The appearance of SiCSBD increases the application range of SBD from 250V to 1200V. At the same time, its high temperature characteristics are good. From room temperature to 175°C, which is limited by the shell, the reverse leakage current hardly increases. In the application field of rectifiers above 3kV, SiCPiN and SiCJBS diodes have attracted much attention due to their higher breakdown voltage, faster switching speed, smaller size and lighter weight than Si rectifiers.

2, SiC MOSFET device

Si power MOSFET devices have ideal gate resistance, high-speed switching performance, low on-resistance and high stability. It is the preferred device in the field of power devices below 300V. It is reported that a SiC MOSFET with a blocking voltage of 10kV has been successfully developed. Researchers believe that SiC MOSFET will occupy an advantageous position in the field of 3kV to 5kV. Despite many difficulties, the research and development of SiCMOSFETs with large voltage and current capabilities has made significant progress.

In addition, there are reports that the reliability of the gate oxide layer of SiC MOSFET has been significantly improved. It has good reliability at 350℃. These findings indicate that the gate oxide layer will hopefully no longer be a significant problem for SiC MOSFETs.

3, silicon carbide insulated gate bipolar transistor (SiC BJT, SiC IGBT) and silicon carbide thyristor (SiC Thyristor)

Previously reported a silicon carbide P-type IGBT device with a blocking voltage of 12kV, and has a good forward current capability. The on-resistance of SiC IGBT devices can be compared with unipolar silicon carbide power devices. Compared with Si bipolar transistors, SiC bipolar transistors have 20-50 times lower switching loss and lower conduction voltage drop. SiCBJT is mainly divided into epitaxial emitter and ion implanted emitter BJT, and the typical current gain is between 10-50.

Regarding the silicon carbide thyristor, there are reports introducing a 1 square centimeter thyristor chip with a blocking voltage of 5kV, a current of 100A (voltage 4.1V) at room temperature, and a turn-on and turn-off time of tens to hundreds of nanoseconds.