Was tatsächlich transportiert wird
A silicon crystal is grown in a crucible of fused quartz, and any impurity in that crucible ends up in the chip. Only a few deposits on the planet are clean enough. The sand is not the product — it is the container the product is grown in, and it is consumed every time.
- Das Material
- High-Purity Quartz
- Die Varietät
- High-purity quartz sand, impurities measured in parts per million
- Wo es beginnt
- United States — Spruce Pine, North Carolina — the source of most of the world's crucible-grade quartz
Schritt für Schritt und Grenze für Grenze
United States · Spruce Pine, North Carolina gehalten von Quartz producers (Bergmann)
An unremarkable-looking quarry
Pegmatite is mined and the quartz separated from feldspar and mica. It then goes through a long purification sequence — flotation, acid leaching, chlorination — to strip aluminium, iron, titanium and sodium down to parts per million.
Warum hier: An accident of geology. These pegmatites formed with unusually little of the trace elements that ruin quartz for this purpose.
Germany · Fused-quartz manufacturers gehalten von Crucible makers (Hersteller)
Made into crucibles
The sand is fused into crucibles — bowls that will hold molten silicon while a crystal is pulled from it.
Warum hier: Fused-quartz manufacture is its own specialised industry, separate from both mining and chipmaking.
China · Polysilicon plant gehalten von Polysilicon producers (Chemisch)
Meanwhile, the silicon itself
Ordinary quartzite is reduced with carbon to metallurgical silicon at about 99%, then converted to trichlorosilane, distilled and redeposited as polysilicon — up to eleven nines of purity for semiconductors.
Was mit dem Rest geschah: This step is essentially electricity turned into purity, which is why it migrated to wherever power is cheapest.
Warum hier: Solar-grade polysilicon needs six or seven nines; semiconductor-grade needs eleven. The extra nines are what separate the two industries.
Japan · Crystal growers gehalten von Wafer manufacturers (Hersteller)
Growing the crystal
Polysilicon is melted in the quartz crucible and a seed crystal is slowly pulled and rotated out of it, growing a single cylindrical crystal up to 300 mm across and two metres long.
Was mit dem Rest geschah: The crucible is consumed. That is the whole reason this journey starts at a sand quarry rather than a silicon plant.
Warum hier: Crystal growing is dominated by a small number of Japanese, Korean, German and Taiwanese firms.
Taiwan · Fab, Hsinchu or Tainan gehalten von Foundry (Hersteller)
Hundreds of steps on a wafer
Deposition, lithography, etch, repeated hundreds of times, building transistors and copper wiring layer by layer. Tungsten fills the contacts; hafnium oxide forms the gate dielectric; neon lases the light that prints the pattern.
Warum hier: Leading-edge fabs are among the most capital-intensive facilities ever built and exist in very few places.
Vietnam · Assembly and test, then the world gehalten von Assemblers and device makers (Hersteller)
Millions of chips
Wafers are diced, packaged, tested and soldered onto boards. From 1,000 kg of a specific sand from one American county, a few million finished chips.
Warum hier: Six countries and roughly six months, for something that weighs a few grams.
Dies ist ein ausgearbeitetes Beispiel. Es verfolgt eine angegebene Ausgangsmenge anhand veröffentlichter typischer Ausbeuten und Ausbringungsgrade, sodass die Verhältnisse nachprüfbar sind; es handelt sich nicht um den Nachweis einer bestimmten Lieferung. Routenfakten — welche Länder, welche Prozesse und warum das Material nicht einfach anderswo verarbeitet werden kann — sind aus öffentlichen Berichten zusammengestellt.