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by GhettoComputers
1683 days ago
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Yes it is refined and doped, my point is that he leaves out the sourcing of essential materials that you don't refine but must get that is already pure, it has to be purer than any random silicon its like saying just get any sand that people will assume comes from beaches for construction when its essential that they are not worn or have rounded edges, except this is so specialized that it must come from one mine in the world. The limit was well understood in Soviet Russia with their inability to source the raw materials of comparable purity to produce microchips, even if the design was the same, the USSR was not able to produce them without what is considered essential to chips of good quality. https://www.sciencedirect.com/science/article/abs/pii/S00652... Even today China cannot match the quality of American chips and relies on US raw materials from Spruce Pine for manufacturing chips. It isn't optional, its like saying you can make a 1:1 steak with nothing but beef bones or chicken. https://ashvegas.com/bbc-report-spruce-pines-high-quality-qu... >This ultra-pure mineral is essential for building most of the world’s silicon chips – without which you wouldn’t be reading this article. |
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(A note in passing: the semi industry doesn’t use hyperpure silicon. They use a lesser grade and add epitaxial layers.)
The crucible can stand the high temperature of molten silicon. The purified polycrystalline silicon is melted in the crucible. Then a single crystal ‘seed’ is dipped in the molten silicon and slowly withdrawn, while rotating. That’s how you make a high purity single crystal silicon ingot.
Before it’s zone refined, the poly is synthesized by reducing high purity silane gas (SiH4), which was in turn produced from quartz sand.
It would be interesting to know if the industry is still using natural quartz crucibles - the latest wafer size is now 450 mm - nearly 18 inches. Maybe someone else here can comment whether the traditional pulling process will be used at 450 mm.