This article is reproduced from the [Electronic Engineering Album] public number
It is predicted that the electric vehicle market will maintain double-digit growth in the next decade. As the electric vehicle market gradually enters a better state, silicon carbide (SiC) power devices have broad prospects. In fact, most EV manufacturers are integrating or evaluating the use of SIC power devices in different EV systems, including traction inverters, DC-DC converters, and on-board chargers. In addition, as a fast-charging infrastructure necessary for large-scale promotion of electric vehicles, silicon carbide power devices are also a good choice.
According to McKinsey & Company, China is already the world's largest market for electric vehicles, and from 2020 to 2030, China will maintain the top spot of the most dynamic market with an annual growth rate of 24%. As a result, China has become a number one target for major silicon carbide device companies such as STMicroelectronics, Wolfspeed, Rohm Semiconductor, Infineon, Onsemi and Mitsubishi Electric, which together account for more than 80 percent of the global market. On the other hand, as the U.S.-China trade war has shaken China's semiconductor industry, the Chinese government has urged Chinese companies to catch up with the latest and most strategic technologies, including silicon carbide and gallium nitride, and ultimately achieve the goal of self-sufficiency.
In this context, Knowmade, as a company that has tracked silicon carbide patents for many years, has focused its recent research on Chinese companies that are changing China's emerging silicon carbide supply chain.
Over the past two decades, Japanese companies have dominated the number of silicon carbide patents, with Mitsubishi Electric, Sumitomo Electric, Denso, Fuji Electric and Toyota Motor pushing for patents, while China's silicon carbide patenting activity has grown rapidly over the past decade since the early 2010s. As a result, since 2018, Chinese patent applicants have surpassed Japanese patent applicants to gain a leading position in the intellectual property of silicon carbide (Figure 1).
In addition, Chinese companies have continued to make efforts in patent applications in recent years to catch up with foreign leading enterprises, while Japan's patent activities have entered a stable period since 2013, reflecting the high technological maturity of Japanese silicon carbide companies. "An interesting phenomenon is that China's patent applications are evenly distributed between materials (bulk silicon carbide, silicon carbide epitaxial wafers) and power appliances (silicon carbide MOSFETs and JFETs, etc.), and about half of the siC material inventions are concentrated on equipment and tools for the growth of siC, which is the first technical challenge and obstacle that all new entrants to the siC bare wafer business will face," dr. Rémi Comyn said. He is a technology and patent analyst in The Composite Semiconductor and Electronics Division of Knowmade. In fact, there is no unified standard path for silicon carbide growth technology, which is different from silicon growth technology.
The classification of Chinese patent applicants in the power-based silicon carbide supply chain shown in Figure 2 shows that there are already a large number of Chinese enterprises with intellectual property rights in all aspects of the supply chain. For example, in the field of bulk silicon carbide, research institutions such as the China Electric Power Research Institute, Shandong University and the Chinese Academy of Sciences (Shanghai Institute of Ceramics, Institute of Physics, Semiconductor Research Institute) have taken the lead in research on the growth of silicon carbide crystals in China, and have promoted the emergence of domestic industrial enterprises, such as Beijing Tianke Heda (founded in 2006), Shandong Tianyue (established in 2010) and Hebei Tongguang Crystals (established in 2012).
Recently, a number of new start-ups have been born from these institutes, such as Shanxi Shuoke Crystal Co., Ltd. (China Electronics) and Guangzhou Nansha Wafer Semiconductor Technology Co., Ltd. (Shandong University). In addition, several enterprises engaged in the development and commercialization of sapphire substrates for LED products have also entered the field of block silicon carbide intellectual property rights, such as Shanghai Jingfeng Mingyuan Semiconductor (entered in 2019) and Zhejiang Jingsheng Electromechanical (entered in 2020).
Finally, IP players such as Beijing Century Jinguang (entered in 2011) and Xiamen Sanan Optoelectronics (entered in 2020) aimed at establishing a vertical integration model also entered the field of block silicon carbide patents. With the support of the Shanghai Institute of Ceramics of the Chinese Academy of Sciences, Century Jinguang established its first four-inch pilot production line in 2012 and obtained the intellectual property rights of at least 17 patented inventions owned by Beijing Huajin Chuangwei Electronics in the field of block silicon carbide in 2016 and 2017.
On the other hand, Sanan Optoelectronics (whose silicon carbide patent portfolio was analyzed in a previous article on Knowmade) acquired Nortel New Materials in 2020 and began to establish a production platform in the Changsha Hi-Tech Industrial Park, covering all production steps from the growth of block silicon carbide crystals to wafers, power devices, packaging and testing.
In the field of patents for silicon carbide power devices (Figure 3), the main patentees in China are public research institutions (Xidian University, University of Electronic Science and Technology of China and Institute of Microelectronics of the Chinese Academy of Sciences) or state-owned enterprises (CRRC, State Grid and China Electricity Science and Technology). However, several companies specializing in silicon carbide, such as Basic Semiconductor (founded in 2009), Beijing Century Jinguang (2010) and Tektron Semiconductor Technology (2011), have now gained a foothold in the intellectual property landscape.
In addition, several companies engaged in the power semiconductor industry have also recently advanced into the patent territory of silicon carbide devices, such as Founder Microelectronics (entered in 2018), Wuxi Xinjie Energy (entered in 2018) and China Resources Microelectronics (entered in 2019). Similar to the situation of block silicon carbide patents, start-ups continue to emerge from domestic research institutions, such as Guolian Wanzhong (founded in 2015, linked to China Electronics), Dongguan Qingxin (founded in 2018, linked to Xi'an Jiaotong University), Xiamen Zisi (established in 2019, linked to the Semiconductor Research Institute) and Zhongke Hanyun Semiconductor (founded in 2019, linked to the Institute of Microelectronics of the Chinese Academy of Sciences). Pinegate Semiconductor, a start-up founded in 2018 by North Carolina State University alumni, entered the field of silicon carbide patents in 2019. This is a company engaged in the design of silicon carbide and gallium nitride power devices, mainly relying on X-FAB to produce silicon carbide devices (using planar gate MOSFET technology). The fabless-free company began mass production of its first siC wafers in September 2021.
"Overall, China has twice as many SIC MOSFET patent applications as SiC diodes, reflecting how difficult it is to develop reliable SIC MOSFETs, especially due to problems with gate oxide structure," Rémi Comyn noted. This can be confirmed by the majority of leading patent applicants, with the exception of Sanan Optoelectronics and Wuxi Xinjie Energy, whose patent activities were initially focused on silicon carbide diodes (Figure 3). "Interestingly, Chinese IP firms have a closer network of devices, modules and circuits than bulk SICs and SICs epitaxial sheets, especially between research institutions and corporate participants," adds Rémi Comyn.
Although China started late in patenting activities related to modules and circuits (starting in 2015), more than 800 inventions have been produced. Patent activities related to siC circuits have been strongly supported by Chinese academics such as Nanjing University of Aeronautics and Astronautics, South China University of Technology, and Xi'an Jiaotong University (Figure 2). Most importantly, in order to meet the future of the electric vehicle market, the leading companies in China's power module market, Star Semiconductor and Hongwei Technology, are also entering the field of silicon carbide patents in 2020/2021. In addition, Yuanshan Electronics, a pure silicon carbide company founded in 2020, also announced its first silicon carbide power module related patents in 2021 and will further consolidate its position in China's domestic supply chain.
In summary, China is accelerating its patenting activities to support the development of silicon carbide technology and to support the emergence of a complete domestic supply chain to stabilize its power semiconductor production line. Chinese patent applicants cover the entire supply chain, with relatively mature IP participants at every step of the way, who come from diverse backgrounds (academia, the corporate world, foundries, IDMs, integrators, pure R&D, etc.), and have a dense network of IP cooperation and transfer. Therefore, in most parts of the supply chain, the technology gap between China and foreign suppliers is expected to narrow.
Chinese companies will focus more on increasing the penetration of domestic silicon carbide products, a market that in the past was dominated by foreign companies. Chinese silicon carbide companies are backed by several companies that have been hit by U.S. restrictions, such as Huawei, which has invested in several key domestic companies in the patent space (Shandong Tianyue, Dongguan Tianyu, Hantian Tiancheng, etc.) to secure their future siC supply.
In this context, considering the domestic market size and the bottleneck caused by the low production capacity of block silicon carbide, Chinese silicon carbide enterprises have a long way to go on the road to conquering new overseas markets. In fact, less than 3% of Chinese patents are filed overseas. However, by filing more foreign patents than their domestic counterparts, certain Chinese companies, such as Shandong Tianyue, a manufacturer of silicon carbide substrates, have shown their international ambitions.