Growing a Perfect Crystal

10 atomic recall cards. Export to Anki and let spaced repetition do its slow work.

In Anki: File → Import, choose this TSV, set field separator to Tab, deck = Sand to Silicon · Ch 04, note type = Basic.

Front	Back
What is the melting point of silicon?	1,414°C.
Who invented the crystal-pulling technique, and in what year?	Jan Czochralski, in 1916 — by accident, when he dipped his pen into molten tin instead of his inkwell.
What material is the crucible that holds molten silicon made from?	High-purity SiO₂ (quartz) — the same Spruce Pine quartz discussed in Chapter 1.
Why is the Cz chamber backfilled with argon before the melt?	To protect the molten silicon from oxygen, which would contaminate it.
What is the approximate pull rate of the seed crystal during Czochralski growth?	About 1 mm per minute.
What happens to the crucible while the seed rod is pulled upward?	It counter-rotates — rotating in the opposite direction — to keep the temperature gradient symmetric and impurity distribution uniform.
How large and how heavy is a finished 300 mm Cz ingot?	About 300 mm in diameter, over a meter long, and weighing roughly 200 kg — about as much as a small motorcycle.
How many grain boundaries does a completed Cz ingot contain, end to end?	Zero. It is a single crystal across roughly 10²⁵ atoms.
What environmental disturbance can ruin a boule during pulling?	Vibration — even a passing truck on the road outside.
For what two applications is float-zone silicon preferred over Czochralski silicon?	Power electronics and certain detector-grade silicon, where the highest purity is required and large diameters are not needed.