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How are single crystals of silicon grown from molten silicon?

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A periodic table element square for silicon shows atomic number 14, symbol Si, atomic weight range, electron configuration, and name. Icons indicate it is a solid nonmetal with diamond crystal structure and equal relative strength. Labels explain each property. — silicon Chemical properties of the element silicon.

Single crystals of silicon are primarily grown from molten silicon using the Czochralski method, a technique developed by Jan Czochralski in 1916.12

The Czochralski Process

To grow a crystal, electronic-grade silicon is heated to approximately 1,500 °C (2,700 °F) in a fused quartz crucible. Small amounts of specific elements, such as phosphorus, arsenic, or boron, are added to achieve the desired semiconductor properties.1

The growth procedure involves the following steps:
* Seeding: A small "seed" crystal is attached to a rod and lowered until it touches the surface of the molten silicon.12
* Rotation and Pulling: The rod and the crucible are rotated in opposite directions while the rod is slowly withdrawn.1
* Growth: As the rod is pulled, a single crystal grows at the interface between the seed and the melt. Computer-controlled systems monitor the weight of the crystal to adjust the pulling rate, ensuring a consistent diameter.2

This process allows for the production of large, high-purity ingots that are subsequently sliced into wafers for integrated circuits.13