National Sun Yat-sen University’s Breakthrough in 6-Inch Crystal Growth Technology Boosts Taiwan’s Semiconductor Sector
Silicon Carbide (SiC) crystal, the essential next -generation semiconductor material, presents strategic prominence in industries such as electric car manufacturing, 6G communications, defense, aerospace, and green power. Ahead of its peers in Taiwan, the Center of Crystal Research at National Sun Yat-sen University (NSYSU) announced the successful development of the N-Type 4H 6-inch SiC monocrystalline. During the development process, all related facilities and procedures were made in Taiwan, including crystal growth furnaces, crucibles for material storage, thermal field design, crystal growth technology, and quality characterization. This further ensures the growth efficiency, stability, and reasonable manufacturing costs of SiC crystal, and will undoubtedly enhance the competitive advantage of Taiwan's semiconductor industries in the global market.
It is well known that SiC presents good performance regarding high voltage, high power, and thermal emission. However, the technical barrier for crystal growth is very high. It requires time and experienced professionals to implement the whole growth process. Currently, there is still a long way to go to improve the stability and yield rate. "For now, NSYSU's Center of Crystal Research is the only research institute to have successfully developed N-Type 4H 6-inch SiC monocrystalline with a 19mm central thickness, 14mm edge thickness, and a growth rate of 370um/hr, and the enhanced growth rate can be replicated. ", said Dr. Mitch Ming-Chi Chou, chair professor of Department of Materials and Optoelectronic Science, also the Vice President for International Affairs at NSYSU.
Dr. Chou also emphasized the prominence to establish the made-in-Taiwan technical supply chain from academic research, to facilities design, including crystal growth furnaces, crucibles, design of thermal fields, growth parameters, and defect inspection. By not relying on assistance from overseas manufacturers, research and production costs could be effectively reduced.
In 2022, the NSYSU research team utilized N-Type 4H 6-inch SiC growth furnaces and successfully grew 6-inch monocrystalline. Dr. Chou emphasized the researchers put lots of efforts to enhance the efficacy from the laboratory level to the industrialization level. The researchers kept adjusting growth parameters and eventually replicate the stable growth of N-Type 4H 6-inch SiC monocrystalline in February 2023. As a result, manufacturers utilizing these technologies will gain a significant competitive advantage and increased profitability.
“Taiwan’s semiconductor industry is in a leading position in the global market. Though, the development of advanced appliances, such as high power devices, electric cars, and low earth orbit satellites, has been limited without accomplished techniques of SiC crystal growth for next-generation semiconductor material”, said Dr. Chou. The NSYSU team has made a breakthrough in SiC crystal growth technology and plans to collaborate with industrial partners, enabling them to leverage the strategic positions in Taiwan’s semiconductor industry.
Currently, 4-inch and 6-inch SiC wafers are still main sizes in the market, but there is an increasing demand for 8-inch SiC wafers. Dr. Chou indicated that NSYSU team is developing N-Type 4H 8-inch SiC growth devices. Besides, the team is building a high-vacuum environment for Semi-insulating Silicon Carbide (SI.-SiC). “There have been discussions about Tesla incorporating the use of SiC wafers. According to the original article, Tesla will still equip high-temperature endurance components with SiC, as low-temperature ones with regular silicon wafers, utilizing different encapsulation lines. Thus, SiC wafers are still indispensable for Tesla, and demands for electric cars and charging stations are still high”, said Dr. Chou.
Since 2004, NSYSU’s Center of Crystal Research has put lots of effort in developing high-temperature crystals and growth techniques. It is the only research institute that is able to develop large-size SiC crystals with the growth temperature of more than 2300 Celsius. Through collaboration with partners from the industry of medicine, semiconductor, optoelectronics and laser, as well as sponsorship by the National Science and Technology Council and MOE’s higher education SPROUT projects, the center has obtained outstanding industry-academia reputations. Besides, the center has built two oversea research center in Lithuania and the Republic of Latvia respectively, developed laser crystals for Thin Disc Laser (TDL). The project presents magnificent results as well.