What are the differences between first-generation, second-generation, and third-generation semiconductors?
Third-generation semiconductors are wide-bandgap semiconductor materials, mainly silicon carbide (SiC) and gallium nitride (GaN), which have the characteristics of high breakdown electric field, high saturation electron velocity, high thermal conductivity, high electron density, high mobility, and the ability to withstand high power.
1. Materials
The first generation of semiconductor materials, invented and implemented in the 1950s, were represented by silicon (Si) and germanium (Ge), with silicon, in particular, forming the foundation of all logic devices. The computing power of our CPUs and GPUs is inseparable from silicon. The second generation of semiconductor materials, invented and implemented in the 1980s, mainly refers to compound semiconductor materials, represented by gallium arsenide (GaAs) and indium phosphide (InP).
Gallium arsenide plays an important role in radio frequency power amplifier devices, while indium phosphide is widely used in optical communication devices. The third generation of semiconductors, invented and put into use at the beginning of this century, has given rise to emerging semiconductor materials with wide bandgap characteristics such as silicon carbide (SiC), gallium nitride (GaN), zinc oxide (ZnO), diamond (C), and aluminum nitride (AlN), and are therefore also known as wide bandgap semiconductor materials.
2. Band gap
First-generation semiconductor materials have indirect band gaps and narrow band gaps; second-generation semiconductor materials have direct band gaps and narrow band gaps; third-generation semiconductor materials have wide band gaps and direct band gaps across all components. Compared to traditional semiconductor materials, the wider band gap allows the materials to operate at higher temperatures, stronger voltages, and faster switching frequencies.
3. Application
First-generation semiconductor materials are primarily used in discrete device and chip manufacturing. Second-generation semiconductor materials are mainly used to fabricate high-speed, high-frequency, high-power, and light-emitting electronic devices, and are also excellent materials for manufacturing high-performance microwave and millimeter-wave devices, widely used in microwave communication, optical communication, satellite communication, optoelectronic devices, lasers, and satellite navigation. Third-generation semiconductor materials are widely used to fabricate high-temperature, high-frequency, high-power, and radiation-resistant electronic devices, applied in semiconductor lighting, 5G communication, satellite communication, optical communication, power electronics, aerospace, and other fields.
Third-generation semiconductor materials are considered a new driving force for the development of the electronics industry. Taking silicon carbide (SiC), a typical representative of third-generation semiconductors, as an example, silicon carbide has the characteristics of high critical magnetic field, high electron saturation velocity and extremely high thermal conductivity, making its devices suitable for high-frequency and high-temperature applications. Compared with silicon devices, silicon carbide devices can significantly reduce switching losses.
Therefore, silicon carbide can be used to manufacture high-voltage, high-power power electronic devices such as MOSFETs, IGBTs, and SBDs for applications in smart grids, new energy vehicles, and other industries. Compared to silicon devices, gallium nitride (GaN) features a high critical magnetic field, high electron saturation velocity, and extremely high electron mobility, making it an excellent choice for ultra-high frequency devices suitable for applications in 5G communications, microwave radio frequency, and other fields.
Third-generation semiconductor materials possess characteristics such as resistance to high temperatures, high power, high voltage, high frequency, and high radiation. Compared to first-generation silicon-based semiconductors, they can reduce energy loss by more than 50% and reduce equipment size by more than 75%. Third-generation semiconductors belong to the post-Moore's Law concept, with relatively low requirements for manufacturing processes and equipment. The challenge lies in the preparation of third-generation semiconductor materials, while also requiring advantages in design.
II. Opportunities in Third-Generation Semiconductors
Due to disadvantages in manufacturing equipment, processes, and costs, third-generation semiconductor materials have only been used on a small scale for many years, unable to challenge the dominance of silicon-based semiconductors. Currently, silicon carbide substrate technology is relatively simple; domestic companies have achieved 4-inch mass production, and 6-inch research and development has been completed. Gallium nitride (GaN) fabrication technology still needs improvement. Domestic companies can currently produce 2-inch substrates in small batches, have the capability to produce 4-inch substrates, and have developed 6-inch samples.
Driven by new market demands such as 5G and new energy vehicles, third-generation semiconductor materials are expected to experience accelerated development. The performance of silicon-based semiconductors can no longer fully meet the needs of 5G and new energy vehicles, amplifying the advantages of third-generation semiconductors such as silicon carbide and gallium nitride.
Furthermore, advancements in manufacturing technology have led to a continuous decrease in the cost of silicon carbide (SiC) and gallium nitride (GaN) devices, fully demonstrating their cost-effectiveness advantages. Preliminary assessments suggest that the core growth drivers for third-generation semiconductors will be concentrated in areas where SiC and GaN each hold a distinct advantage.
