SK Siltron Co., Ltd. — AI supply-chain exposure

SK Siltron is an SK Group subsidiary and one of the handful of companies that grow and polish the bare silicon wafers every chip starts from. It supplies large-diameter wafers to both memory and logic fabs, and also produces silicon-carbide wafers used in power devices. It sits at the very base of the chain — the substrate layer beneath logic and memory — where a small club of producers feeds essentially the entire semiconductor industry.

The structural hook is that wafer supply is concentrated and slow to expand. Crystal-growing capacity takes years to build and qualify, so when leading-edge demand surges the wafer floor can tighten before anything downstream does. Being unlisted inside SK Group, its fortunes track the same memory cycle as its sister companies, but its exposure is broader — every fab, memory or logic, needs its output. The model places it mid-chain as a quiet input chokepoint rather than a visible product.