"New Energy Semiconductor" New Nuclear "Core" in the Great era-- understanding Silicon Carbide in one article

The cornerstone of the semiconductor industry is the chip. According to the difference of semiconductor materials, semiconductors are divided into three generations: most of the first generation semiconductor materials are high purity silicon, the second generation compound semiconductor materials include Shenhua gallium and indium phosphide, and the third generation compound semiconductor materials are represented by silicon carbide (SiC) and gallium nitride (GaN).

Silicon carbide is an important basic material for the development of the third generation semiconductor industry. Silicon carbide power devices can effectively meet the requirements of high efficiency, miniaturization and lightweight of power electronic systems because of their excellent resistance to high voltage, high temperature and low loss.

At the same time, it has obvious advantages in new energy vehicles, photovoltaic power generation, rail transit, intelligent Electroweb and other fields.

Founder Securities Lu Zhuoyang and Chen Hang believe that at present, silicon carbide is limited by yield and technical influence, there is still a gap between domestic supply and demand, and the effective production capacity is insufficient. In the next few years, the upstream material terminal market of SiC will deeply benefit from the increasing demand of downstream applications such as automobile electrification, electric vehicle supporting equipment construction, 5G base station and data center construction, which can be expected in the future.

Iteration and comparison of the third generation semiconductors

The third generation semiconductors, represented by silicon carbide and gallium nitride, have obvious advantages in many aspects, such as high temperature, high voltage and high current, so they are more suitable for the fabrication of high temperature, high frequency, anti-radiation and high power devices.

The process of the first and second generation semiconductor materials has gradually approached the physical limit, and Moore's law has gradually failed. The third generation is expected to break through the bottleneck of traditional semiconductor technology, complement the first and second generation semiconductor technology, and play an important role in energy saving and emission reduction, industrial transformation and upgrading, and the birth of new economic growth points.

Compared with the previous two generations of semiconductor materials, the third generation semiconductor silicon carbide has the advantages of large band gap, large drift rate, large thermal conductivity, large breakdown field strength and so on. as a result, power semiconductor devices that are more suitable for harsh conditions such as high power, high frequency, high temperature and high voltage can be developed.

On the whole, the high pressure resistance of silicon carbide is 10 times that of silicon, the high temperature resistance is 2 times that of silicon, and the high frequency ability is 2 times that of silicon. Compared with silicon-based module, the module composed of silicon carbide diode and switch tube (all-carbon module) not only has the advantage of intrinsic characteristics of silicon carbide material, but also can reduce the module volume by more than 50% and reduce electron conversion loss by more than 80% in application, thereby reducing the overall cost.

The application scene of silicon carbide material is relatively clear. According to the different resistivity, silicon carbide wafers can be divided into conductive type (15-30m Ω cm) and semi-insulating type (no less than 10 ^ 5 Ω cm). Among them, conductive silicon carbide substrate (silicon carbide epitaxy) is mainly used to manufacture high temperature and high voltage power devices, which has been widely used in electronic and power fields, such as new energy vehicles, photovoltaic, intelligent Electroweb, rail transit and other fields. the market is large. Semi-insulating silicon carbide substrate (gallium nitride epitaxy) is mainly used in microwave radio frequency devices and other fields, such as power amplifiers in 5G communications and radio detectors in national defense. With the accelerated construction of 5G communication network, the market demand is increasing obviously.

According to the "2021-2025 Silicon Carbide substrate Industry Deep Market Research and Investment Strategy recommendation report" released by the New thinking Industry Research Center, the global market size of silicon carbide substrate materials is about 180 million US dollars in 2019. Due to the increasing performance requirements of power devices and RF devices in the downstream industry, the third generation semiconductor materials are gradually replacing the previous two generations, and the demand is growing rapidly. It is estimated that by 2025, the global market size of silicon carbide substrate materials will reach about 1.59 billion US dollars.

Demand for power devices released by new energy vehicles, photovoltaic and rail transit, benefiting from the depth of conductive substrates

In 2020, China has a production capacity of about 400000 SiC conductive substrates and 260000 devices. The production capacity of semi-insulating substrate is nearly 180000, and the production capacity of GaN RF devices is mainly GaN-on-SiC, with a production capacity of about 160000. The production capacity increases rapidly in the aspects of substrate, epitaxy and devices.

There is a huge demand for silicon carbide in the new energy vehicle market.

The components related to power semiconductor applications in the new energy vehicle system architecture include: motor drive system, vehicle charging system (OBC), power conversion system (vehicle DC/DC) and non-vehicle charging pile. Silicon carbide power devices are located between 1KW-500KW and work frequency between 10KHz-100MHz. In new energy vehicles, silicon carbide power devices are mainly used as main inverters in motor drive systems, which can significantly reduce the volume, weight and cost of power electronic systems, and increase power density.

Among them, the use of silicon carbide in 800V voltage platform is the core of electric drive upgrade. Silicon carbide has the characteristics of high temperature resistance, low switching loss, high voltage and high frequency resistance, which makes silicon carbide MOSFET the best choice for upgrading the voltage platform of electric vehicles to 800V. At the same time, the application of silicon carbide devices does not increase the cost of bicycles.

Photovoltaic industry policy is good, continue to release SiC demand

In photovoltaic, wind power and other power generation systems, inverters convert different voltage levels of DC into AC to drive household appliances, lighting and other AC loads.

SiC inverter provides a variety of perfect power conversion and access solutions for solar photovoltaic, wind power and other renewable power generation systems, which will also lead to the growth of the SiC market. SiC inverters are superior to silicon-based devices in terms of energy saving, system size reduction and life cost. These performance indicators are essential for wind power generation systems that need to successfully utilize wind energy with as little power loss as possible.

Rail transit: rail transit is widely used, and the advantages of SiC are fully demonstrated.

A large number of power semiconductor devices are used in rail transit vehicles, in which traction converter is the core equipment of locomotive high-power AC drive system. Silicon carbide devices applied here can greatly give full play to the high temperature, high frequency and low loss characteristics of silicon carbide devices. Improve the efficiency of the traction initiator device, in line with the rail transit large-capacity, lightweight and energy-saving traction current generation device application requirements, and improve the overall efficiency of the system.

5G, defense-driven RF market is rising steadily, and semi-insulating substrates are developing rapidly.

Gallium nitride device is replacing the application of LDMOS in communication base station, radar and other broadband fields because of its good thermal conductivity, high frequency and high power. It is the most ideal microwave radio frequency device so far, so it has become the core microwave radio frequency device of 4G/5G mobile communication system, new generation active phased array radar and other systems.

5G communication and national defense two-wheel drive RF GaN market

The application scenarios of RF GaN mainly include 4G LTE and 5G telecom infrastructure, mobile phones, national defense, satellite communications, RF power and civil radar. In the next few years, 5G communications and defense industry will continue to be the main drivers of the GaN RF device market, accounting for 41% and 49% of the total market by 2026, respectively. New opportunities will also be brought to emerging fields such as satellite communications.

According to Yole, the total market value of GaN RF devices will increase from US $891 million to more than US $2.4 billion, with an CAGR of 18% from 2020 to 2026.

The next driver of Mobile Satellite Communications or GaN RF Market

In the field of radio frequency and microwave communication, the anti-ionizing radiation ability of GaN makes it an excellent choice for satellite communication. In addition, the high electron mobility of GaN enables it to better amplify the power of satellite frequency band, which is beneficial to the uplink of satellite communication.

At present, mobile satellite communications have been deployed in fixed satellite communication systems. Due to the strict authentication cycle, the penetration of GaN in mobile satellite systems is still limited, but in the long run, mobile satellite communications may be the next market driver of GaN RF solutions.

At present, the downstream demand of silicon carbide industry is strong, but the bottleneck of upstream material end process and yield needs to be broken through, and the lack of production capacity seriously restricts the application of silicon carbide. Whether upstream or downstream, there is a situation that "he who gets the material gets the world".