EasyNetWorld

From cell phones to electric cars! What is the next generation of compound semiconductors?

Compound semiconductor is composed of two or more chemical elements belonging to different groups in the periodic table of elements, such as gallium arsenide (GaAs) combined with Group III and Group V semiconductors, which is also the most representative and most widely used compound semiconductor. Compared to elemental silicon semiconductors, compound semiconductors have unique material properties such as direct band gap, high breakdown voltage and high electron mobility, enabling optoelectronics, high-speed, high-power devices and integrated circuits.

For a simple example, a transistor made of gallium arsenide, where the electron movement speed is about 6 to 8 times that of the ordinary silicon transistor, so we are very suitable for high-speed circuit applications. Everyone may be curious, since there are so many benefits, why are the other main semiconductors on the market now based on silicon?

One of the main reasons for this is that compound semiconductor transistors are not as reliable and radioactive as silicon-based components, making it easier to make high-density integrated circuits and therefore not suitable for logic chips that require a large number of transistors, such as cpus and graphics processors for artificial intelligence computing, which are currently very popular in computers. Using current advanced silicon semiconductor processes, such as TSMC's 5-nanometer transistors, the number of transistors in a chip can easily reach billions or even tens of billions of levels.

Black applications of compound semiconductors

Although not suitable for logic chips, compound semiconductor materials are well suited for some current emerging applications due to their unique properties, and their size is unmatched by silicon semiconductors. The compound semiconductor is considered suitable for high-efficiency power electronics applications, such as 5 g and above 5 g (or even 6 g) high-frequency power amplifiers for millimeter wave and terahertz communications, converter technology for electric vehicles and fast charging.

Unlike the more mature gallium arsenide, gallium nitride (GaN), silicon carbide (SiC), indium phosphide (InP) in the new generation of compound semiconductors have excellent potential for these emerging applications, and the market growth is quite exciting. Silicon carbide and gallium nitride are often referred to internationally as "wide-band gap semiconductors", and their energy gap is about three times that of silicon (Si), so they can be used for high-power operation without causing transistor damage.

At present, silicon carbide transistors are mainly used in electric vehicle power conversion systems and charging piles, which require high power applications. Gallium nitride is used for relatively small power, such as the very popular mobile phone and pen fast charge system currently developed in China. Due to the high-speed characteristics of compound semiconductors, these systems can be operated at a higher switching speed, so we can effectively improve the working power electron density to meet the requirements of thin and small.

On the other hand, gallium nitride and indium phosphid, due to their relatively high electron saturation rates and electron mobility, are well suited for the application of RF front-end power amplifiers in next-generation millimeter wave/terahertz communications. However, due to the limitation of material properties, silicon transistors are difficult to achieve high power output at high operating frequencies. Therefore, Gan and inp have broad application prospects in the next generation RF front-end power amplifiers and integrated circuits.

Beyond Moore's Law -- beyond Moore

Moore's Law is one of the most famous laws in the semiconductor field, which predicts the number of transistors that a silicon semiconductor can fit in its integrated circuit. As transistors shrink in size, they double roughly every two years. But due to physical constraints, the continuation of Maurer's Law has slowed down.

The International Semiconductor Technology Roadmap (ITRS) clearly identifies three major challenges for the future development of the semiconductor industry :(1) More Moore's Law to explore the ultimate miniaturization limits of transistors; (2) The application of multi-mole technology to improve the efficiency, function and value of the chip; (3) The post-Moore's Law era (beyond CMOS) will pursue next-generation electronic components that can replace the current CMOS.

Of these three challenges, compound semiconductors play a key role in the "More than Moore" project. In a system, a variety of different semiconductors are used to achieve different functions in the system to achieve the overall performance optimization. Of course, in current applications, silicon-based semiconductors are definitely an indispensable or missing role, but the role of compound semiconductors will also become more and more heavy.

At present, whether it is gallium nitride, silicon carbide or indium phosphide in the entire process, there is still a lot of fine space for research and development of the reliability of materials and components. Taiwan is currently a world leader in silicon semiconductors and has recently invested a lot of resources in the research and development of next-generation compound semiconductors. Based on the solid foundation we have built in the semiconductor-related industry chain over the years, we believe that in the near future, we will also play a very important role in next-generation compound semiconductors.