27 January 2026

Silicon: from metallurgical grade to semiconductor and quantum purity

Key insights from this briefing

What is the difference between metallurgical-grade silicon and semiconductor-grade polysilicon?

Metallurgical-grade silicon is typically around 98% to 99% pure and is used in industrial applications such as aluminium alloys. Advanced semiconductor manufacturing requires vastly higher purity, with the briefing highlighting "eleven nines" polysilicon to minimise defects in modern integrated circuits.

Why is isotopically pure silicon-28 important for quantum computing?

Natural silicon contains silicon-29, whose nuclear spin can interfere with fragile quantum states. Enriching silicon in non-magnetic silicon-28 reduces this source of noise and can extend qubit coherence times, making it attractive as a material platform for scalable quantum devices.

Excerpt from this briefing's Industry Insight

Silicon's strategic role changes completely with purity. Metallurgical-grade silicon is a large industrial input, while ultra-high-purity polysilicon and single-crystal material underpin advanced semiconductors and solar technologies. The briefing also highlighted adjacent materials such as silicon carbide and gallium nitride for high-power defence and aerospace electronics, and isotopically purified silicon-28 for quantum computing. In each case, strategic value depends on the ability to refine and manufacture material to extraordinarily exacting specifications.

This is an excerpt from the Industry Insight in the full Market Briefing. Log in to access the complete briefing.