View source for Physics:Boule (crystal)

{{Short description|Synthetic ingot of crystal}} 
{{Crystallization}}
[[Image:Monokristalines Silizium für die Waferherstellung.jpg|thumb|left|upright=0.5|[[Earth:Monocrystalline silicon|Monocrystalline silicon]] boule]]

A '''boule''' is a [[Earth:Single crystal|single-crystal]] ingot produced by synthetic means.<ref>{{cite book|url=https://books.google.com/books?id=WJzmBQAAQBAJ&dq=boule+silicon&pg=PA56|title=Fundamentals of Silicon Carbide Technology: Growth, Characterization|isbn=9781118313527|access-date=March 1, 2017|last1=Kimoto|first1=Tsunenobu|last2=Cooper|first2=James A.|date=24 November 2014|publisher=John Wiley & Sons }}</ref>

A boule of [[Chemistry:Silicon|silicon]] is the starting material for most of the [[Engineering:Integrated circuit|integrated circuit]]s used today. In the [[Physics:Semiconductor|semiconductor]] industry synthetic boules can be made by a number of methods, such as the Bridgman technique<ref>{{cite book|url = https://books.google.com/books?id=izaSIlOahJkC&dq=bridgman+technique&pg=PA485 | title = Springer Handbook of Crystal Growth | date = 2010 | isbn = 9783540747611 |access-date=February 25, 2017| last1 = Dhanaraj | first1 = Govindhan | last2 = Byrappa | first2 = Kullaiah | last3 = Prasad | first3 = Vishwanath | last4 = Dudley | first4 = Michael | publisher = Springer }}</ref> and the [[Physics:Czochralski process|Czochralski process]], which result in a cylindrical rod of material.

In the Czochralski process a [[Earth:Seed crystal|seed crystal]] is required to create a larger crystal, or ingot. This seed crystal is dipped into the pure molten silicon and slowly extracted. The molten silicon grows on the seed crystal in a crystalline fashion. As the seed is extracted the silicon solidifies and eventually a large, cylindrical boule is produced.<ref>{{cite web|url=https://books.google.com/books?id=ce-__G-L5iEC&dq=Czochralski+process&pg=PP11|title=Continuous Czochralski Process Development|access-date=March 1, 2017|last1=Rea|first1=Samuel N.|year=1978}}</ref>

A semiconductor crystal boule is normally cut into circular [[Engineering:Wafer (electronics)|wafers]] using an inside hole diamond saw or diamond [[Engineering:Wire saw|wire saw]], and each wafer is lapped and polished to provide substrates suitable for the fabrication of [[Physics:Semiconductor device|semiconductor device]]s on its surface.<ref name="BOSE2013">{{cite book|author=BOSE|title=IC Fabrication Technology|url=https://books.google.com/books?id=vnzvAwAAQBAJ&pg=PA53|year=2013|publisher=McGraw Hill Education (India) Pvt Ltd|isbn=978-1-259-02958-5|pages=53}}</ref>

The process is also used to create [[Chemistry:Sapphire|sapphire]]s, which are used for substrates in the production of blue and white LEDs, optical windows in special applications and as the protective covers for watches.<ref name="Colinge2004">{{cite book|author=J.-P. Colinge|title=Silicon-on-Insulator Technology: Materials to VLSI: Materials to Vlsi|url=https://books.google.com/books?id=RR0WinYaN14C&pg=PA12|date=29 February 2004|publisher=Springer Science & Business Media|isbn=978-1-4020-7773-9|pages=12}}</ref>

==References==
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[[Category:Crystals]]
[[Category:Semiconductor growth]]

{{Sourceattribution|Boule (crystal)}}