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SUMCO Corporation

SUMCO makes the ultra-pure silicon wafers that computer chip makers build their chips on.

SUMCO sells the raw material that every computer chip is built on. It makes giant, perfectly round discs of ultra-pure silicon called wafers, and chip factories buy them by the millions. Those factories then carve transistors and circuits into the wafers, chop them up, and turn them into the processors inside phones, cars, laptops, and data centers. SUMCO almost never sells to you directly. Its customers are the big chip makers, and they keep coming back because a wafer with even a tiny speck of dust can ruin an entire batch of chips.

Think of it like a bakery that only sells the dough. SUMCO does not bake the final cake—it just makes sure the dough is flawless, the right size, and delivered on time. Roughly all of its revenue comes from silicon wafers, split between 300-millimeter wafers used for the most advanced chips and smaller 200-millimeter and 150-millimeter wafers used for simpler chips and sensors. The biggest chunk of sales goes to memory chip makers, the companies building the storage inside your phone and the memory used in AI servers.

The business is a rollercoaster. When chip demand is hot, wafer prices rise and SUMCO makes fat profits. When demand cools, chip makers cut production and SUMCO's sales fall fast. The company spends heavily on new plants and equipment because building wafer factories is expensive and takes years. It also pays a dividend and has been investing in extra capacity to serve the booming demand for AI-related chips. SUMCO traces its roots back to Japan in the 1930s and 1940s, when the country's early electronics industry began, and it has grown into one of the two biggest wafer makers in the world alongside Shin-Etsu Chemical.

Saved answer · last researched 14 Oct 2026