Semiconductor Materials Supply Chain: Concentration Risk and Input Criticality

Semiconductor fabrication draws on a narrow and geographically concentrated set of material inputs, and China's rolling export controls since mid-2023 have turned long-documented supply concentration into observed disruption across gallium, germanium, tungsten, and rare earth oxides. This report maps the full input stack, from Siemens-process polysilicon, where a handful of producers hold most advanced-node-purity capacity, through specialty process gases exposed by the Ukraine conflict, to the NdFeB magnets embedded in lithography tools themselves. Each chokepoint is assessed for utilization, geographic concentration, the feasibility of substitution or restocking, and the pace of Western capacity investment through early 2026. Near-term risk is most acute for high-purity gallium, heavy rare earth stabilizers, and specialty neon, while polysilicon and bulk silicon carry longer-horizon concentration risk.