By Jamie Liao, SEMI Taiwan
At the Power Electronics Conference in Taipei, hosted by SEMI Taiwan, industry professionals met to talk about the state of the industry. The need to improve product efficiency, lower power consumption, and streamline production processes is driving continuous innovation in power electronic technologies. SEMI invited speakers from leading research institutes and pioneering organizations in power electronics, such as Delta, Epiworld, GaN Systems, Toyota, and Yole Développement, present about the latest trends and technologies across the entire supply chain. The conference covered from materials and processes to final applications — discussing topics on both semiconductor materials (SiC and GaN) and automotive semiconductors.
Compound Semiconductor Materials: Transforming the Industry
As Pierric Gueguen, business unit manager of the Power Electronics and Compound Semiconductor Business at Yole Développement, pointed out, the need to revolutionize thermal management and thermal interface technology has made power electronics the next area of innovation in materials and applications. For example, SiC and GaN are transforming the supply chain and package structure of power semiconductors. As the values afforded by GaN continue to increase, its application market is estimated to grow 83 percent from 2015 to 2021, with power suppliers accounting for 60 percent of the growth. On the contrary, SiC will grow at a relatively slow pace (21 percent) during the same period.
Charles Bailley, senior director of Sales and Marketing for Asia GEO at GaN Systems, said that both GaN and SiC are wide band gap (WBG) semiconductors in terms of electrical and physical properties. However, in terms of the electron mobility in two-dimensional electron gap (2DEG, GaN (1,800μ) is better than SiC (125μ). That is why GaN is able to achieve high efficiency and high power density. Still, SiC has higher thermal conductivity (3.5W/m-K) than GaN (1.5W/m-K), and is more suitable for high power applications.
SiC and GaN: Key Role in Process Innovations
Gan Feng, general manager at Epiworld, said that in terms of materials, SiC is a polycrystalline compound. Its commonly available types including 4H-SiC, 6H-SiC, 15R, and 3C, all with 1:1 silicon-carbon ratio. On this base material, over 200 crystal structures can be formed, but only 4H is suitable for making vertical power components. As 4H-SiC has a stable 3C structure, it can be used in epitaxial growth on diagonally cut substrates.
According to Herman Chang, CTO and general manager of Delta, using discrete components requires connecting these components individually while taking parameters of IGBT and MOSFET into account at the same time, posing great challenges in production and design to application designers. This is where module makers can help. Although power electronics has not been a favorite for industry investments, the growth potential of power modules is worth taking a serious look at, as semiconductors, including SiC and GaN, are getting into the mainstream.
Kimimori Hamada, project general manager at Toyota, said that the company is working to increase fuel efficiency by 10 percent and reduce the size of the power control unit by 20 percent. To this end, Toyota is developing the next-generation automotive power semiconductors. Electric cars with SiC MOSFETs and SiC JBS diodes on board show better energy efficiency in road tests, demonstrating the advantage of SiC components over silicon counterparts. In addition, PCUs with SiC components are able to achieve higher control frequencies, which help reduce the sizes of power modules, coils, and capacitors.
According to the report from Yole Développement, the SiC power component market is expected to reach over US$110 million in 2020. Application areas such as telecommunication, solar energy, and electric vehicle are some of the niche markets with high profit potential. Clearly, the growth potential of compound semiconductor materials is not to be underestimated.
Terry Tsao, president of SEMI Taiwan, said that SEMI maintains a positive outlook on the growth of compound semiconductors. At SEMICON Taiwan 2017, there will be exhibition areas, international forums, and networking activities dedicated to compound semiconductors, allowing exhibitors to showcase their products and technologies while offering a platform for information exchange and opportunities for partnerships.
November 22, 2016