Recently, Qingchun Semiconductor officially launched the 1200V/3.5m Ω SiC MOSFET chip (model: SG2MA3512B) and corresponding SOT227 package product (model: S1P04R120SSE) to meet customers' needs for high-performance and high-power applications. Figures 1 and 2 respectively show the output and breakdown characteristic curves of the chip's single tube SOT227 package (Figure 3). At room temperature, the chip has a resistance of 3.5 milliohms and a breakdown voltage of not less than 1600V. Through design and process improvements, this product has optimized the high-temperature distribution resistance on the chip's current path, especially the compromise design between channel resistance and N-type resistance, achieving excellent temperature coefficient of resistance. The test results show that the on resistance of the chip at 175 ℃ is only 1.5 times that at room temperature.

With the continuous improvement of the quality and manufacturing technology of silicon carbide (SiC) materials, high current and low on resistance SiC power chips can be realized, which will further simplify the packaging of power modules and accelerate the application of SiC in new energy vehicles and other fields. This product has significantly reduced the impact of some key defects on performance through optimized design of structure and process; At the same time, a lower specific resistance design technology was adopted to reduce the chip area under the same resistance, thereby controlling the trend of decreasing yield and achieving mass production of high current, low resistance chips. On the other hand, SiC MOSFETs are susceptible to various interferences in high-power applications, leading to gate misoperation such as parasitic turn on caused by self charging of capacitors between upper and lower transistors, and crosstalk between different bridge arms. This product improves the ratio of input capacitance Ciss to transfer capacitance Crss and increases the threshold voltage by optimizing the layout of the gate microstructure, thereby suppressing crosstalk. As shown in Figure 4, the capacitance ratio of Ciss/Crss of the product reaches over 580 at 800V voltage. Figure 5 compares the relationship between device threshold voltage and temperature. The threshold voltage reaches 3.2V at 25 ℃ and is higher than 2V at 175 ℃. In terms of application, the chip is compatible with 18V and 15V driving voltages, adapting to the development needs of different driving circuits and facilitating direct substitution of IGBT in various applications.

    The Institute of Electrical Engineering of the Chinese Academy of Sciences has completed the packaging of the low-noise half bridge module based on the chip product SG2MA35120B, and the dual pulse test waveform is shown in Figure 6. Ning Puqi, a researcher at the Institute of Electrical Engineering of the Chinese Academy of Sciences, said: "With the support of the cross team project of the Chinese Academy of Sciences and the special project of the national key research and development plan for new energy vehicles, this single chip has achieved 350A current output energy when the ambient temperature is 150 ° C and the bus voltage is 800V. This chip is particularly suitable for high-power vehicle electric drive systems and can effectively suppress the problems of uneven current and temperature caused by parallel connection of a large number of small current chips.

Fig 6. 双脉冲测试波形。

    Qingchun Semiconductor always adheres to technological leadership, and its series of silicon carbide products have gained unanimous recognition from users for their excellent performance and high reliability. At present, Qingchun Semiconductor has completed the development and mass production of dozens of silicon carbide devices on voltage platforms such as 750V, 1200V, 1700V, and 2000V, and has laid out a sound production capacity guarantee system and strict quality management system. Qingchun Semiconductor will continue to make new breakthroughs on the path of China's original silicon carbide technology source and leading supplier.