GALLIUM

What Is Gallium, Gallium Arsenide & Gallium Nitride And Where Do I Use It?

Elemental gallium (chemical symbol Ga) does not occur in free form in nature, but as the gallium compounds that are in trace amounts in zinc ores and in bauxite.

Gallium is a soft, silvery metal, and elemental gallium is a brittle solid at low temperatures. Gallium arsenide is a III-V direct bandgap semiconductor (different from silicon).
Gallium is mainly used for the manufacturing of Gallium arsenide which is the primary chemical compound of gallium in electronics. Smaller quantities are used for the manufacturing of Gallium nitride (GaN).

Gallium arsenide (GaAs) owns a high socio-economic importance being widely used for radio frequency chipsets in mobile and satellite communication, for laser diodes in fiber based communication systems, for LEDs in displays, automotive and lighting applications, for sensors in avionic, space and defence systems.

To a much lesser extent than GaAs, gallium nitride (GaN) is required for certain applications in fields similar to those of GaAs, wherever high efficiency, high power, high frequencies or high temperatures are important.

GaAs is often used as a substrate material for the epitaxial growth of other III-V semiconductors including: Indium gallium arsenide, Aluminium gallium arsenide and others.

Where is Gallium and Gallium Arsenide Produced?

The production of gallium metal is often connected with the processing of bauxite to aluminium. The majority (ca. 80%) is located in China. The only production site in Germany is owned by companies located Canada.
Gallium arsenide in the required high-pure quality is produced by only a few companies in the world (one in Europe, others in Japan, China).

Specific Issues for Gallium Arsenide

A particular concern for gallium criticality is its main use in growing and emerging markets in its compound form Gallium arsenide that forms the core substrate for semiconductors.
Gallium arsenide is manufactured from the raw materials arsenic (As) and gallium (Ga). The semiconductor is always used encapsulated in articles in very small quantities.
The economic importance of Gallium arsenide was established due to its very unique combination of properties that makes it non-substitutable (e.g. by silicon) in many demanding high-tech applications.
The consumer has no direct contact with Gallium arsenide hence there is absolutely no risk in using GaAs based products and technologies. Associated risks at the workplace are adequately controlled by already existing workplace safety regulations.
The harmonised classification of Gallium arsenide under the EU’s CLP regulation opens the opportunity for even more stringent regulations under REACH. However, none of gallium compounds is on the list of substances of very high concern.
Before any further regulatory action is taken, an obligatory risk assessment option analysis and check of proportionality by active involvement of industry expertise shall be performed.

Recycling

Recycling of gallium is only possible from industrial production waste. Gallium arsenide (GaAs) and gallium nitride (GaN) wafer manufacturing processes are considered the main secondary source of the metal, with around 40-50% waste generated and recycled in a closed loop. FCM’s aim is to increase this recycling rate to 70-80% and if more Ga waste from outside the EU would come back to the EU, this % could even go up to 90%.

From the perspective of an industrial company it seems possible to increase the recycling rate to 70 – 80% if Ga containing waste from outside the EU could be used as well.

Applications