Revolutionaries in the Semiconductor Industry: Gallium

Intrroduction: On August 12, 2022, the Bureau of Industry and Security (BIS) of the US Department of Commerce issued export restrictions, involving advanced semiconductors, turbine engines, and other fields, including semiconductor materials to diamond and gallium oxide materials .

On July 3, 2023, the General Administration of Customs of the Ministry of Commerce of China announced the implementation of export controls on items related to gallium and germanium.

Gallium and related materials have become important and key materials in the fields of science and technology. What kind of applications do they have in the semiconductor industry and how important are they?

The semiconductor industry is at the heart of the global high-tech sector

• Semiconductors have a huge impact on economic development and scientific and technological progress. They play a key role in many important fields such as information technology, communications, automobiles, medical care, and new energy, and are the basis for driving global digital and intelligent development.

In terms of market size, the semiconductor industry is large and growing. According to SIA data, the global semiconductor market sales will reach US$573.5 billion in 2022.

Furthermore, the importance of the semiconductor industry lies in its pivotal position in the global supply chain. Semiconductors are the core components of many high-tech products and have a major impact on the performance and functionality of products in smartphones, computers, automobiles, medical equipment and many other fields.

However, the semiconductor industry is also facing some challenges, such as fast technology iteration, large R&D investment, and a long industrial chain.

Therefore, accelerating the development of the semiconductor industry is the focus of enhancing a country's technological strength.

Gallium is a revolutionary in the semiconductor industry

Gallium (Gallium, chemical symbol Ga) is an element in the fourth period of the periodic table, located in the III-A main group of elements, between aluminum and indium. Gallium was discovered by French chemist Paul Emile Lecoq de Boisbaudran in 1875, and its name comes from the Latin "Gallia", which means France.

Gallium is a soft metal that is silvery white in its standard state. Gallium can be easily cut at room temperature and melts at a temperature slightly above room temperature (29.76°C), so if you hold gallium in your hand, it will probably melt slowly. But at low temperatures, gallium becomes very hard, even harder than iron.

In terms of chemistry, gallium usually exists in the +3 oxidation state and can form various compounds, including those with elements such as oxygen, sulfur, nitrogen, halogens, and phosphorus. Gallium exists in the form of Ga3+ in most compounds.

Semiconductors are usually classified based on their band structure and elemental composition. The most basic classification is based on their elemental composition, such as elemental semiconductors (eg, silicon, germanium) and compound semiconductors (eg, gallium arsenide, gallium nitrogen). According to their conductive properties, semiconductors can be divided into n-type and p-type. The following are several representative stages of semiconductors:

• The first generation of semiconductors: Early semiconductors were mainly elemental semiconductors, mainly silicon, and germanium. Silicon has become the basis of the semiconductor industry due to its abundant silicon source and good semiconductor performance.

• Second-generation semiconductors: mainly compound semiconductors, such as gallium arsenide (GaAs). Due to the characteristics of energy band structure, this kind of material shows better performance than silicon in special application scenarios such as high frequency and high power.

• Third-generation semiconductors: mainly include wide bandgap semiconductors such as gallium nitride (GaN) and silicon carbide (SiC). They have higher electric field strength, higher electron saturation drift velocity, and higher thermal conductivity, which make the m have excellent performance in extreme environments such as high voltage, high frequency, and high temperature.

• Fourth-generation semiconductors: mainly refer to 2D semiconductor materials, such as phosphide black phosphorus, boron nitride, etc. Due to their unique two-dimensional properties, these materials open up new possibilities for the exploration and application of physical properties.

In the field of semiconductors and chips, several gallium-containing semiconductors have a wide range of applications. Specifically:

• Gallium Arsenide (GaAs): Gaas is a direct bandgap semiconductor, which means it can effectively convert electricity into light and is therefore used to major red and infrared LEDs. Because of its high electron Mobility, Gaas is often used to make High-Frequency microwave electronic devices, such as mobile phones, radios, and radars.

• Gallium Arsenide has a higher electron mobility than silicon, making it a better performer in high-frequency electronic devices. In addition, GaAs can operate at higher temperatures, so it is widely used in space and military applications.

• Gallium Nitride (GaN): GaN is a wide bandgap semiconductor that can operate at higher electric field strengths than silicon and gallium arsenide, giving it an advantage in high-voltage power electronics. At the same time, GaN has high thermal conductivity , making it perform well in high-power devices. In addition, GaN is also a direct band gap semiconductor, so it is used to manufacture high-efficiency blue and white LEDs, greatly promoting innovation in the field of lighting.

• Gallium oxide (Ga2O3): Compared with other semiconductor materials, the emerging Ga2O3 has a wider band gap (about 4.8 eV), which makes it have significant advantages in high-voltage, high-frequency power electronic devices. It also means it can work in more extreme environments, such as higher temperatures and more radiation. On the other hand, the preparation cost of Ga2O3 is relatively low, which gives it an advantage in large-scale applications. In the future, Ga2O3has great application prospects in mobile phone fast charging, 5G communication, power supply, new energy vehicles, LED and radar.

• Gallium Antimonide (GaSb): GaSb has a very narrow bandgap, making it useful for infrared detectors and infrared lasers. This means it has potential applications in areas such as communications, medical care, military and environmental monitoring. In addition, GaSb also has potential applications in thermophotovoltaics, which can be used to efficiently convert heat energy into electricity. This is an important material for infrared detection, which can be used to manufacture infrared detectors and infrared lasers.

The following table is a comparison of their performance and disadvantages, challenges and advantages.

Gallium distribution, the possible impact of export controls

It was considered as a strategic and key metal during the Second World War. At present, the total reserves of gallium metal in the world are about 230,000 tons. China's reserves of gallium metal rank first in the world, accounting for about 80% of the world's total reserves- 85%.

190,000 tons in China, 4,500 tons in the United States, 11,400 tons in South America, 53,900 tons in Africa and 19,500 tons in Europe

Note: The global reserves of associated ores exceed 1 million tons, and mining and purification are more difficult.

The current major consuming countries and regions of gallium are Japan, the United States, and Europe, among which the consumption of gallium in Japan and the United States accounts for 80% of the global gallium consumption.

As far as the United States is concerned, according to the data of its National Minerals Information Center, from 2018-2021, the proportion of different sources of imported gallium in the United States is as follows: China, 53%; Germany and Japan, 13% each; Ukraine, 5%; others, 16%.

Obviously, having resources and having a mining technology system cannot be ignored.