On November 10, 2023, Wenzhou Xinshendai Technology Co., Ltd. grandly released the 850V Cynthus for high voltage and high current HEMT power device applications at the 2023 World Young Scientists Summit ® Series of silicon based gallium nitride (GaN on Si) epitaxial products. Industry clients and well-known investment institutions compete to understand and cooperate.
         The 850V Cynthus for high voltage and high current HEMT power device applications released this time ® Compared with other substrates for HMET power devices, the series of silicon based gallium nitride (GaN on Si) epitaxial products can achieve larger wafer sizes and more diverse applications, and can quickly be introduced into the mainstream silicon based chip process of FAB factories, which has its unique advantages in improving the yield of power devices. By adopting the most advanced silicon-based chip manufacturing process and integrating with Si CMOS drivers for high yield hybrid integration, utilizing the 850V Cynthus of chip generation technology ® The series of GaN-on-Si epitaxial products can develop 650V, 900V, and 1200V HEMT products, especially suitable for designing smaller and more efficient power supply solutions.
    Core Generation 850V Cynthus ® The release of the series GaN on Si epitaxial products is of iconic significance in the market. Traditional gallium nitride power devices, due to their highest voltage generally remaining in the low-voltage application stage, have narrow application fields, which limits the growth of the gallium nitride application market. For high-pressure GaN-on-Si products, due to the heteroepitaxial process of gallium nitride epitaxy, there are difficulties such as lattice mismatch, expansion coefficient mismatch, high dislocation density, and low crystal quality during the epitaxial process. Therefore, epitaxial growth of high-pressure HMET epitaxial products is very challenging. Under the leadership of Dr. Zhong Rong, the founder and chief scientist of Xinshendai Technology, the high uniformity of epitaxial wafers has been achieved by improving the growth mechanism and accurately controlling the growth conditions; Utilizing unique buffer layer growth technology to achieve high breakdown voltage and low leakage current of epitaxial wafers; Excellent two-dimensional electron gas concentration has been achieved through precise control of growth conditions. Thus, the difficulties brought by GaN-on-Si heteroepitaxial growth were successfully overcome, and an 850V Cynthus suitable for high voltage was successfully developed ® Series products (Figure 1).

Figure 1: Core Biotech 850V Cynthus ® Series GaN on Si epitaxial products

Specifically
    Really high pressure resistant. In terms of voltage resistance, it is truly achieved in the industry to maintain low leakage current under 850V voltage conditions (Figure 2), ensuring the safe and stable operation of HEMT device products in the voltage range of 0-850V, ranking among the forefront in the domestic market. By utilizing core generated GaN-on-Si epitaxial wafers, 650V, 900V, and 1200V HEMT products can be developed, driving gallium nitride towards higher voltage and high-power applications.
    The world's top level of pressure control. Through the improvement of key technologies through core generation, the thickness of the epitaxial layer is only 5.33 μ M can achieve a safe working voltage of 850V, achieving 158V/ μ Vertical breakdown voltage per unit thickness of m, error less than 1.5V/ μ m. The error is less than 1% (Figure 2 (c)), which is at the world's top level.
    The first GaN on Si epitaxial product in China to achieve a current density greater than 100mA/mm. Higher current density, suitable for high-power applications. By using smaller chips, smaller module volumes, and fewer thermal effects, module costs can be greatly reduced. Suitable for application scenarios such as power grids that require higher power and conduction current (Figure 3).
    Extremely low cost price, with a cost reduction of over 70% compared to similar domestic products. The core generation first uses the best unit thickness performance improvement technology in the industry to greatly reduce the time and material cost of epitaxial growth, making the cost of GaN-on-Si epitaxial wafers close to the range of existing silicon device epitaxy, thereby significantly reducing the cost of gallium nitride devices and promoting the development of gallium nitride device products in a deeper and broader direction.

(c) Vertical breakdown voltage per unit thickness

Figure 2 850V Cynthus ® Breakdown voltage of series gallium nitride epitaxial wafers

Figure 3 850V Cynthus ® Source drain current density of D-mode HEMT devices without field plates in the series

Figure 4 850V Cynthus ® Series epitaxial wafers after wafer casting

Dr. Zhong Rong said, "Due to the adoption of a new epitaxial growth process, we can significantly alleviate the thermal stress between GaN and silicon substrate, regulate the flatness of epitaxial wafers, and use a unique zero defect thin film preparation technology to significantly improve the quality of thin film growth in each layer of the epitaxial layer. Through self-developed high-voltage control technology, we have achieved 850V Cynthus ® The high voltage, high stability, and high quality of the series epitaxial wafers; At the same time, GaN HEMT device design companies can use field boards or other means to increase the available voltage to well over 850V, which means that we are collaborating with excellent device design companies, and our current technology is highly likely to be used in 900V scenarios. In addition, due to the significant advantages of our new method in cost control, the preparation cost can be reduced to 30% of the original. Through our method, 850V Cynthus ® The cost of a series of epitaxial wafers can be much lower than that of existing silicon epitaxial wafers, which means that gallium nitride devices will play an important role in 800V electric drive or other high-voltage applications. At the same time, compared to silicon carbide devices, they will also have greater cost advantages, proving that there will be greater development space for high-voltage gallium nitride devices in the industrial and energy application markets in the future. At present, the company is in an upward stage and is seeking opportunities for upstream and downstream cooperation and launching a new round of financing