Editing Czochralski method (section)

== Production of Czochralski silicon ==
[[File:Monokristalines Silizium für die Waferherstellung.jpg|thumb|left|Crystal of [[Czochralski-grown silicon]]]]

[[Semiconductor]]-grade silicon (only a few parts per million of impurities) is melted in a [[crucible]] at {{Convert|1425|C|F K}}, usually made of high-purity [[quartz]]. The crucible receives a ''charge'' consisting of high-purity [[polysilicon]].<ref>https://www.google.com.pa/books/edition/Springer_Handbook_of_Electronic_and_Phot/3JQ4DwAAQBAJ?hl=en&gbpv=1&dq=Czochralski+polysilicon&pg=PA305&printsec=frontcover</ref> Dopant impurity atoms such as [[boron]] or [[phosphorus]] can be added to the molten silicon in precise amounts to [[Doping (semiconductor)|dope]] the silicon, thus changing it into [[P-type semiconductor|p-type]] or [[N-type semiconductor|n-type]] silicon, with different electronic properties. A precisely oriented rod-mounted [[seed crystal]] is dipped into the molten silicon. The seed crystal's rod is slowly pulled upwards and rotated simultaneously. By precisely controlling the temperature gradients, rate of pulling and speed of rotation, it is possible to extract a large, single-crystal, cylindrical ingot from the melt. Occurrence of unwanted instabilities in the melt can be avoided by investigating and visualizing the temperature and velocity fields during the crystal growth process.<ref>{{cite journal |first1=Jalena |last1=Aleksic |title=Temperature and Flow Visualization in a Simulation of the Czochralski Process Using Temperature-Sensitive Liquid Crystals |journal=[[Annals of the New York Academy of Sciences|Ann. N.Y. Acad. Sci.]] |volume=972 |issue= 1|year=2002 |pages=158–163 |doi=10.1111/j.1749-6632.2002.tb04567.x |bibcode = 2002NYASA.972..158A |first2=Paul |last2= Zielke |last3=Szymczyk |first3=Janusz A. |pmid=12496012 |s2cid=2212684 |display-authors=etal}}</ref> This process is normally performed in an [[Inert gas|inert]] atmosphere, such as [[argon]], in an inert chamber, such as quartz. The quartz crucible is normally discarded after the process is terminated which normally happens after a single ingot is produced in what is known as a batch process, but it is possible to perform this process continuously, as well as with an applied magnetic field.<ref>https://www.google.com.pa/books/edition/Springer_Handbook_of_Electronic_and_Phot/3JQ4DwAAQBAJ?hl=en&gbpv=1&dq=Czochralski+polysilicon&pg=PA305&printsec=frontcover</ref>