Semiconductors and Critical Minerals: The Materials Behind the Chip Industry

When most people think of semiconductors, they think of silicon wafers processed in massive fabrication plants by companies like TSMC, Samsung, and Intel. Silicon is indeed the foundation of the digital economy, but an increasing share of the most strategically important semiconductor devices are built not from silicon but from compound semiconductor materials, alloys of two or more elements from the periodic table that offer performance characteristics silicon cannot match.

Gallium arsenide (GaAs) enables the radio frequency amplifiers in every smartphone and 5G base station. Gallium nitride (GaN) is transforming power electronics by switching energy more efficiently in EV chargers, server power supplies, and military radar systems. Silicon carbide (SiC) has become the inverter material of choice for high-performance electric vehicles, offering lower switching losses and higher temperature operation than conventional silicon. Indium phosphide (InP) is essential for fiber-optic communications and emerging photonic computing technologies.

The minerals that underpin these technologies, gallium, germanium, indium, arsenic, and high-purity silicon feedstock, face significant supply concentration risks. China's 2023 export controls on gallium and germanium were a vivid demonstration that semiconductor mineral supply is a geopolitical tool, not just an industrial commodity. This section examines the critical minerals behind the semiconductor industry, the compound semiconductor technologies they enable, and the export control and supply chain risks that threaten the sector.