Everyone already knows a lot about silicon-based semiconductors in the second generation of semiconductors. Today, what we are going to talk about is the next generation, that is, silicon carbide, an important material in the third generation of semiconductors.
Silicon carbide (SiC), along with gallium nitride (GaN), diamond, and zinc oxide (ZnO), belongs to the third generation of semiconductors. Third-generation semiconductors such as silicon carbide have unique properties such as large band gap, high breakdown electric field, large thermal conductivity, high electron saturation drift speed, and small dielectric constant. Power or electronic components manufactured with this characteristic have smaller size, faster transmission speed, higher reliability, lower energy consumption, and can reduce energy loss by more than 50% at the highest, and the product can be reduced by about 75%. Of particular importance is that third-generation semiconductors can work at higher temperatures, voltages and frequencies.
Therefore, third-generation semiconductors such as silicon carbide have shown great potential in semiconductor lighting optoelectronic devices, power electronics, radio frequency microwave devices, lasers and detection devices, solar cells and biosensors and other devices. In the military, SiC is mainly used for high-power high-frequency power devices.
The production steps of silicon carbide semiconductors include single crystal growth, epitaxial layer growth and device/chip manufacturing, corresponding to substrate, epitaxy, and device/chip respectively. The following article will discuss the development of the localization of the silicon carbide industry around these three aspects.
There are two types of silicon carbide substrates, namely, conductive silicon carbide substrates and semi-insulating silicon carbide substrates. On a conductive silicon carbide substrate, a silicon carbide epitaxial layer can be grown to make a silicon carbide epitaxial wafer, which can be further made into power devices, which are mainly used in new energy vehicles and other fields; on a semi-insulating silicon carbide substrate, nitrogen is grown The gallium nitride epitaxial layer is made of silicon carbide-based gallium nitride epitaxial wafers, which can be further made into microwave radio frequency devices for applications in 5G communications and other fields.
Silicon carbide substrate
The core foreign companies producing silicon carbide substrates are mainly CREE in the United States, II-VI in the United States, and Showa Denko in Japan, which together account for more than 75% of the market. Technically, it is transitioning from a 4-inch substrate to a 6-inch substrate, and an 8-inch silicon-based substrate is under development.
The leading manufacturers in China are mainly TKHD, SDTY, HBTG Crystal Technology, SJJG, ZD Group, etc. China's silicon carbide substrate is mainly 3-4 inches, and TKHD's 4-inch substrate has reached the world's advanced level.
In 2019, China's major silicon carbide technology companies have a 4-inch conductive SiC substrate equivalent capacity of about 500,000 pieces/year, and a semi-insulating SiC substrate equivalent 4-inch capacity of about 200,000 pieces/year. Among them, ZD Electronic Technology Group took the lead in realizing the industrial production of 4-inch high-purity semi-insulating silicon carbide single crystal substrate materials in China in 2018, and its silicon carbide material industrial base has achieved mass production of SiC 4-inch wafers.
China's 6-inch substrate research and development has also achieved breakthroughs, entering the stage of preliminary engineering preparation and small batch production:
In 2017, SDTY independently developed a new high-purity semi-insulating substrate material. Its 4H conductive silicon carbide substrate material product has reached 6 inches, and it has also independently developed a 6-inch N-type (conductive) silicon carbide substrate material.
In 2018, ZGDK also completed the research and development of 6-inch high-purity semi-insulating silicon carbide single crystal substrate.
Also in 2018, TKHD developed 6-inch silicon carbide wafers. In addition, HBTG has also successfully developed a 6-inch silicon carbide substrate in recent years.
On December 19, 2018, SA Optoelectronics Technology Group announced that it has completed all process qualification tests for the commercial version of 6-inch silicon carbide wafer manufacturing technology. And add it to the foundry service portfolio.
On July 19, 2020, SA's third-generation semiconductor project in Changsha started, mainly used for R&D, production and sales of 6-inch SIC conductive substrate, 4-inch semi-insulating substrate, SIC diode epitaxy, SiC MOSFET epitaxy, SIC diode epitaxy Chip, SiC MOSFET chip, silicon carbide device package diode, silicon carbide device package MOSFET.
In July 2017, ZKJN invested in the construction of a silicon carbide growth production line project. The total investment of the project is 1 billion yuan. The project is constructed in two phases. The first phase investment is about 500 million yuan. It is expected to be completed and put into operation in June 2019. After completion, it can produce 50,000 4-inch N-type (conductive) silicon carbide crystal linings annually. Negative film and 5,000 pieces of 4-inch high-purity semi-insulating silicon carbide crystal substrate; the second phase investment is about 500 million yuan, after completion, it can produce 50,000 pieces of 6-inch N-type (conductive) silicon carbide crystal substrate and 5,000 A 4-inch high-purity semi-insulating silicon carbide crystal substrate.
Judging from the above news, China’s domestic 6-inch semi-insulating and conductive substrates already have a technical basis. At least four companies can start engineering and mass production in the next few years. If the speed is fast enough, they will basically Match the speed of commercialization in developed countries.
The most interesting thing is the news released on October 6, 2020 that SXLK's 8-inch silicon carbide substrate has been successfully developed and will soon enter engineering. In the future, China will form a 4-inch as the main body, 6-inch as the backbone, and 8-inch as the successor to the development of silicon carbide substrates, which will basically match the technological research and development speed of developed countries.
Silicon carbide epitaxial wafer
The core foreign companies in the production of silicon carbide epitaxial wafers are mainly Cree, DowCorning, II-VI in the United States, ROHM, Mitsubishi Electric in Japan, and Infineon in Germany. Among them, American companies account for 70-80% of the global share. Technically, it is also transitioning to 6 inches.
The main manufacturers of silicon carbide epitaxial wafers in China are HTTC, DGTY, GMTC, SJJG, and ZGDK of the national brand. At present, the domestic and foreign extension wafers are mainly to provide 4-inch products, and 6-inch epitaxial wafers have begun to be provided. The 6-inch production capacity of 2019 SiC epitaxial wafers is about 200,000 wafers/year.
Among them, the most important is HTTC. The company has formed a complete silicon carbide semiconductor epitaxial wafer production line of 3 inches, 4 inches and 6 inches, and meets the needs of 600V, 1200V, 1700V device production. On May 29, 2014, HTTC's first batch of industrialized 6-inch silicon carbide epitaxial wafers was put into production in the high-tech zone, and the first commercial order product was delivered, becoming the first commercial 6-inch silicon carbide epitaxial wafer provided in China.
In 2012, DGTY achieved an annual industrial production capacity of over 20,000 3-inch and 4-inch silicon carbide epitaxial wafers. Currently, it can also provide 6-inch silicon carbide epitaxial wafers.
GMTY issued an announcement on August 15, 2017 to build and operate 6-inch second and third generation semiconductor integrated circuit epitaxial wafer projects. The first phase of the project invested 450 million yuan.
Silicon carbide device
The core foreign companies in the production of silicon carbide devices are Infineon, which has a market share of 18.5%, and the second echelon led by ON Semiconductor, including STMicroelectronics, Mitsubishi Electric, Toshiba, Vishay Semiconductor, Fuji Electric, Swiss Large-scale semiconductor IDM companies in the United States, Japan, and Europe, such as SA Technology, Rohm, and Semikron. Internationally, 600-1700V SiC SBD and MOSFET have been industrialized, and the withstand voltage level of mainstream products is below 1200V.
Followed by Taiwan-based and continental-based companies, such as IDM companies Yang Jie Electronics, Suzhou Nengxun High Energy Semiconductor, Zhuzhou CRRC Times, CLP 55, CLP 13, Tyco Tianrun, Century Jinguang ; Fabless has Shanghai Zhanxin, Ruineng Semiconductor, Foundry has Sanan Optoelectronics; in terms of modules, Jiaxing Star, Henan Senyuan, Changzhou Wujin Kehua, CRRC Times Electric, etc.
In terms of the technical level of device production lines, the 6-inch SiC power device lines of CRRC Times, Century Jinguang, Global Energy Internet Research Institute, and CLP 55 have already started, and four 6-inch SiC pilot lines have been put into use in China. Among them, the research and development and manufacturing of 6-inch SiC SBD, PiN, MOSFET and other devices of CRRC Times have been done well.
In December 2016, Xinguang Runze's third-generation semiconductor silicon carbide power module industrialization project officially started construction. In September 2018, Xinguang Runze’s first domestic silicon carbide IPM device production line in Xiamen was officially put into production
Shenzhen basically relies on its unique 3D SiCTM technology. The performance of basic semiconductor silicon carbide power devices has reached the international advanced level and can be widely used in new energy power generation, new energy vehicles, rail transit and smart grids.
Yangjie Technology's device products include power diodes, rectifier bridges, Schottky diodes and MOSFETs. Its 4-inch line has doubled its production, and the 6-inch line will be fully operational by the end of 2018. At the same time, the company has strategically deployed 8-inch line IGBT chips and IPM module business and other high-profit products, and the coordinated development of multiple product lines has helped the company increase its market share in power devices.
In May 2018, the first domestic 6-inch silicon carbide MOSFET device wafer manufactured by Shanghai Zhanxin was launched. Wafer-level test results show that various electrical parameters have met expectations. (Note: They officially released a few days ago)
In terms of the technical level of silicon carbide devices, domestic companies are relatively concentrated in low-end areas such as basic diodes and medium and low-voltage devices, and have relatively low market penetration in high-end products that require high device performance and reliability.
The localization of high-voltage devices has recently begun to show some good news.
For example: Tyco Tianrun’s silicon carbide Schottky diodes, silicon carbide MOSFETs and silicon carbide modules, among which the 600V/5A-50A, 1200V/5A-50A and 1700V/10A series of silicon carbide Schottky diode products have been Put into mass production. In addition, Tyco Tianrun has built the first domestic production line for silicon carbide devices, and SBD products cover a voltage range of 600V-3300V. It is also a gratifying breakthrough for high-voltage products.
In addition, China Resources Micro also released its first-generation SiC industrial-grade Schottky diode (1200V, 650V) series products to the market in 2020, which is an example of my country's localization of high-voltage devices.
Finally, add one more point. The above three aspects are introduced separately. In fact, domestic companies that can do the whole process layout from the three aspects of substrate-epitaxial wafer and devices are represented by Sanan Optoelectronics and Century Jinguang. Of course, if you combine all the institutions and enterprises of the Guozihao, you can also be regarded as the third enterprise with full-process layout.
Silicon carbide production equipment
Similar to second-generation semiconductors, my country's silicon carbide production equipment also comes from imported products from the United States, Europe and Japan. For example, Hantian Tiancheng, the first domestic producer of epitaxial wafers, silicon carbide epitaxial wafer growth furnaces and various imported high-end inspection equipment are imported from Germany’s Aixtron company. The epitaxial growth technology has reached the international advanced level of Dongguan Tianyu. The four core SiC-CVD and supporting testing equipment are also imported products.
The localization of silicon carbide equipment has also made some progress in the past two years.
For example, the single crystal growth equipment used for substrate production-silicon growth furnace: on November 26, 2019, Roshow Technology signed a cooperation agreement with Zhongke Steel Research and Guohong Zhongyu, relying on Zhongke Steel Research and Guohong The research and development results that Zhongyu has achieved and continued to produce in the growth process technology of silicon carbide crystal materials, combined with Roshow Technology’s vacuum crystal growth equipment design technology and rich equipment manufacturing technology and experience, are jointly developed and suitable for Zhongke Steel Research The silicon carbide crystal growth equipment of 4 inches, 6 inches, 8 inches and even larger sizes required by the process technology, currently the first batch of 2 sets of sublimation silicon carbide crystal growth furnaces have completed the equipment performance acceptance and delivery.
On February 28, 2020, the China Electric (Shanxi) Silicon Carbide Material Industrial Base was officially put into operation in the Shanxi Transformation Comprehensive Reform Demonstration Zone, and the first batch of equipment was officially launched. According to reports, the first phase of the base project can accommodate 600 silicon carbide single crystal growth furnaces. After the project is completed, it will have an annual output of 100,000 4-6 inch N-type (conductivity) silicon carbide single crystal wafers and 50,000 4-6 silicon carbide single crystal wafers. Inch high-purity semi-insulating silicon carbide single crystal wafer production capacity.
Another example is the silicon carbide epitaxial wafer production equipment-silicon epitaxial furnace:
The 6-inch silicon carbide epitaxial equipment developed by Jingsheng Electromechanical is compatible with 4-inch and 6-inch silicon carbide epitaxial growth. The 4-inch process verification passed at the customer, and the 6-inch process verification is in progress. This equipment is a monolithic device with a deposition speed of 50um/min, thickness uniformity <1%, concentration uniformity <1.5%, and is used in new energy vehicles, power electronics, microwave radio frequency and other fields. The silicon carbide epitaxy equipment developed by the company. The better news is that the 8-inch silicon epitaxial furnace developed by it has passed some customer product performance tests and passed technical verification. It has the characteristics of high epitaxial layer thickness uniformity and resistivity uniformity, and its technical indicators have reached the same level as imported equipment. , Have the basis for mass production.